Explosion, now no start.
 

A bit stumped, frustrated, would love help making a diagnostic task list to get my car started again. MKIII turbo swap into 1989 NA body, ran okay but was tracking down high pressure boost leaks with custom piping to the new intercooler. IN the process i carelessly set the timing wrong, or I think I did. It started with difficulty, ran horribly with a lot of fuel smell, wouldn't rev, and when i opened the throttle it exploded, loudly, and stopped abruptly. Restarted the same way, then did the same thing. Hasn't started since then. found CPS timing badly off but intake cam was still up when crank was at TDC. Turns over, but no sense of any ignition happening. pulling injector resistor connector doesn't affect the turn over sound at all.

Fuel: Fuel pressure is good, tried anywhere from 30psi to 45 with no luck.

Spark: Iridium plugs damp but not damaged, except number 6 plug was dry, also undamaged. cleaned them, checked resistances of plugs, wires, injectors, injector resistors. observed good sequential sparking in all 6 plugs mounted in a threaded metal holder. Engine grounds are all retapped and clean.

Compression: about 155psi in all cylinders.

Turbo impeller turns freely without play.

New RC injectors were working, but i put a new heat shrink on all of them. Don't know that I have any reference on what polarity they need, so if that matters please let me know. worried about injectors stuck open.

Questions:
is that explosion "detonation"? SOunded like the sound of a block on the bench being static pressure tested and having the valve popped open with a mallet to seat it. that type of loud pop but much louder resonating through the exhaust system.
What else should I test?

Thanks!

Mods:

K&N filter to Lexus AFM | 660cc RC | Holley 255 LPM FP | JE/Eagle internals | 2.5" hard pipes | Toyo high flow intercooler| S Sanchez ported head | 1.2mm beaded MHG | compression 9:1 w/0.5 overbore | modified ex mani | CXR 3" full exhaust | Slotted/drilled rotors |New WG spring @12psi w/ dual switching man boost | Colt Mild perf. Cams | Bosch BOV | XTD clutch | Tokico Illumina w/TEMS | ES bushings | 18" Pirelli P-zeros | Manual AFPR

update and no progress
 

Wow. Kind of quiet here. Is it always like this? Anyway, in case anyone reads this, yesterday I pulled the turbo - perfectly good rebuilt stock turbo with no sign of damage. Then while it was off I thought I'd do a leakdown test for boost leaks. Got pressurized to 60psi and found slow leakage from multiple places, greatest was from the gasket between the upper and lower intake manifolds, so I separated them slightly, painted some copper RTV from a spray can in there, and resealed with significant improvement. Then various other slow leaks showed up that didn't seem worth chasing, since it obviously was sealing sufficiently that even at 30psi it wouldn't leak enough to make a big difference.

checked cam timing, both set to stock TDC.

checked all the voltmeter tests you can do without the engine cranking or starting, all were ok, except EFI main relay was 1v below battery voltage, but still within specs with a charged battery. Will check connections and ground there and clean that up.

So that's it. For want of a better idea, I guess I'll put the turbo back on. and try starting it again.

I'm thinking maybe the problem is lack of fuel, for lack of a better idea. Spark and compression and timing all were checked and are pretty easy to observe, though I could stand to double check he igniter circuit to coil wiring. Would like a more direct test of the new RC 650 injectors to be sure they are opening and spraying correctly when installed in the engine, trying to think of how I can be absolutely sure they are operating ok.

I'd like to triple check everything possible before trying to start again. I'm beginning to consider swapping the ECU if I don't come up with a better idea soon. That will involve using an automatic trans ECU and making changes in wiring internally so it works with the manual trans, at least to start it. that's a bit of a PITA, so I was hoping to avoid it.

That's it: no real smoking gun found. Feeling like i'm missing something obvious here. Would love to hear from another real live supra owner out there.

This isn't the busiest of Supra sites, no. I've been pretty busy and haven't had a chance to really read through it but I've been meaning to make some time to go through your post and see what I can come up with.

I'll look it all over tomorrow (it's very late here now) and let you know if I can think of anything that's missing. One issue that comes up from time to time it the CPS being clocked 180? off (refer to the FAQ thread on timing to make sure that one is right). And no, there is not proper polarity for the RC injectors, just a simple coil in there so nothing to worry about unless they're not wired in the proper order.

Thanks for your kind and generous attention. I do appreciate it. I dont know that timing was off by any specific amount. I know it was way off, and I think I must have forgotten to set the crank to tdc. I know the cam timing was correct and still is.

The cam's timing is entirely dependant on the crank's position. Timing is not set in any way if all of the components are not set at a matching degree. The distributor, cams and crank ALL must be at zero or your efforts are wasted. First go and ensure that the mechanical timing is properly set, then set the ignition advance (as detailed in the TSRM). Report back with any additional findings.

EDIT:
Ok, I re-read your post and am a little confused I suppose. Go over the thread linked to below and make sure everything is 100% correctly aligned. If you've removed the cam gears at any point make sure the dowels were installed in the center hole on each cam and likewise on the gears. If you're running adjustable cams dial them to 0? initially.

http://www.toyota-supra.info/forums/...-e-timing.html

timing settings
 

Got this but apparently my response was swallowed by the Verizon network.

Rechecked timing this week. it was set according to the exact procedure you linked to, and cam matchmarks and crank mark are still aligned correctly. The pictures are very nice and clear, and I've set the timing many times before. Unfortunately, the timing advance can't be set without the engine running, but I can approximate it with the engine cranking using a timing gun. I think that type of electrical test for timing would be a good reality check anyway and I hope that will be sufficient proof without pulling the CPS again. The CPS was the last thing I had pulled and reset - and done carefully - before posting the problem on here. The timing gears were removed when rebuilding, They are the stock gears, so position is set by the fit of the gear on the cams.

I will
1) verify that the cam lobes are aligned as expected with the match marks, just to be extra certain, on Saturday.
2)Will check each cylinder for spark with inductive timing gun to verify correct sequence as wiring from igniter to coils was extended and soldered due to fraying and breakage.
3) remove CPS cover and verify armature alignment with crank and cam timing marks at TDC.

I'll let you know when this is completed.

Thanks.

found something!
 

Good instincts on looking at timing. the timing was all set correctly: cams, crank, CPS installation, but I found two wires reversed on the connector to the CPS.

My understanding from the TEWD is that the engine harness connector is supposed to look like:

Blue Red
pin1 pin 2

Black Yellow
pin 3 pin 4

I had black and yellow reversed when I fixed the worn connector. How i had any spark at all I still don't understand.

Now the coil packs are still confusing. In the tewd it doesn't clearly say which wire from the igniter goes to which coil, but labels the wires
IG1 to coil pack connector pin 1,
IG2 to coil pack connector pin 2
and then the third wire to pin 3 isn't labeled with a moniker
coil pack pin 4 is B+ common.



Fixing and putting engine back together. will report back.

The coil pack wiring is a common upset but, oddly enough, it's not something which has made its way into my repository of Supra tech info. It has been posted here in the MKIII forum a couple times though. If you find a good thread with solid info on it let me know and I'll copy it into the FAQ section... I'd look for something but I've got company and had to sneak away to get on here for this long.... The wife's just real funny about me not paying her family enough attention. :dunno:

Coil pack wiring info for 7MGTE
 

7MGTE ignition system wiring specs


WARNING: post edited - had error in my wiring which I hope I corrected. this is my best understanding of how it is supposed to look.

adapted from another forum, TEWD, and also my TCCS manual from the Allen Instutute training manual from 1990


Coil pack order is: (left to right from front of motor)

Coil pack____________To cyls__wire colors

Coil A Passenger coil____1&6____Black, Tan

Coil B Middle coil_______3&4____Green, Tan

Coil C Driver side coil____5&2____White, Tan

To Engine harness per TEWD:
(Here's where it gets messy! The TSRM appears to have the WRONG pin numbers in their diagram on page IG-15 for the ignitor test procedure, where pin 3 and 4 appear to be labeled in reverse. The test procedure should not work as diagramed because the IGDA and IGDB signals do not appear to be correct. More on this below. Also, the functions from the CPU don't wire to the same function at the ignitor. The functions labeled at the ignitor in the diagram don't make sense and my TCCS manual from the Allen Institute says they are WRONG. The functions from the CPU make perfect sense so I included these in my table below. They mean "IGT = ignition trigger, IGDA = ignition determinant A, IGDB = ignition determinant B, and IGF - Ignition Fail)

CP wiring___CP connector _Engine harness wire color __Ignitor 6 way con._____Function __|_ CPU Activating Function__Ignitor 4 way con. pins to activate
Black__________Pin 1 __light blue/red stripe__________Pin 2______________"IG1" __|___IGT and IGDB__________ 2&3 in TEWD (and TCCS manual)
Green_________Pin 3 ___yellow___________________Pin 4 _____________ "IG2" _|___IGT and IGDA __________2&4 in TEWD
White_________Pin 2 ___light blue/yellow stripe_______Pin 1______________"IG3" ___|___IGT alone _________ 2 Alone in TEWD
Tan___________Pin 4 ___Black/orange stripe_________Pin 3______________"B+" -goes to ignition switch and EFI resistor pin 2


coil firing order: Note coil packs fire vehicle right to vehicle left, ie passenger side to driver's side. . that is how most sources number the coils 1-3 or A-C:

Coil A, plug 1 (and 6 wasted) ie "IG1" , IGDA=0, IGDB=1
Coil B, Plug 3 (and 4 wasted) ie "IG2" , IGDA=1, IGDB=0
Coil C, Plug 5(and 2 wasted) ie "IG3, IGDA=0, IGDB=0

Coi. A, Plug 6 (and 1 wasted) IG1 again
Coil B, Plug 4 (and 3 wasted) IG2 again
Coil C, Plug 2 (and 5 wasted) IG3 again

SO to test the ignitor, it should be the following procedure:

Apply a constant +3v where indicated in first column then touch pin 2 with a +3v pins on the ignitor 4 pin connector:

constant 3V transient 3v read resistance
none ignitor Pin 2 coil C connector (center coil) white wire pin 2
ignitor Pin 3 ignitor Pin 2 coil A connector (passenger side coil) black wire pin 2
ignitor Pin 4 ignitorPin 2 coil B connector (driver side coil) green wire pin 2

Note: my digital voltmeter, which is a high end model, does not respond quickly enough to reliably see the drop in resistance in the coil connector wires. I made a bracket for my plugs to watch them fire and confirmed that they work as expected when wired and tested this way.

Update and some progress
 

Well it took a while, because I fried a few links and fuses jumpering the car too late at night and not paying attention. Now I can say the car is back to where it was before the explosion, when it just wasn't quite starting and was misfiring. It catches slightly and sputters just barely for a second. It seems to barely combust, and disconnecting the fuel injector resistor to cut fuel leads to a stronger sputter on the first try. It's like it is flooding before starting. then checking timing while cranking, I get almost no gun flashes, like it's not picking up a spark current. Pulling plug one and trying with plug exposed shows it sparking erratically and weakly and fouled but not wet plug.

So I think I have a problem with spark. I have tested coil and wire resistance, all fine, but I put in new irridium plugs after I tested compression, and i went with a colder plug due to my increased compression ration and plan to boost to 20 or 25psi eventually. I will try again with plain old copper plugs, retest coils and wires, check ignitor transistor, and report back here for posterity.

Questions: when people run colder plugs for high boost do they generally also have aftermarket ignition? WOuld there be any benefit to keeping my plugs and increasing spark power via different ignitor or coils? What are the best upgrades to the ignition, if any?

No, you don't need to make any changes to the ignition system because you're running a colder or hotter plug. The thermal transfer characteristics of a plug have little effect on the spark. Why are you running a colder plug? Preignition problems, damaged spark plugs or high EGT?

colder plugs
 

Yeah, I thought about that after I posted: plug gap should be the overriding determinant of spark. I'm running colder based on various postings on plug choices. I haven't run the engine enough to know where my EGT's will be in various conditions, but that's an obvious and interesting way to select plugs. I'm surprised I haven't noticed that approach posted.

So it's down to the ignitor or coils. And ignitor makes more sense to me. Clearly my spark is inconsistent, and it sure seems like the ignitor fires inconsistently in the TSRM transistor test, no matter how carefully I clean the probe and terminals> I have a replacement from a running motor to test when the weather allows. Thanks.

I don't see that you've mentioned running an extreme amount of boost. It doesn't matter much. It won't hurt anything, they'll just foul frequently if they're too cool.

There's a thread in the FAQ, I believe, about a known grounding problem with the igniters (it's an internal issue). See if you can find it and see if the fix listed works for you.

ignitor didn't fix it
 

Thanks. I already had the ground mod in place. I replaced the ignitor and it is not much different. WIth all the injectors unplugged it behaves EXACTLY THE SAME as with them plugged in. I believe it is sputtering a bit and firing into the intake runner due to fuel from the cold start injector. It sputters a bit more consistently maybe with the new ignitor, but no real change. Also no different with plug to injector resistor connected or not.

So without the injectors making a difference, and good fuel pressure, is it fair to conclude that I'm down to injectors not opening as my problem? If so, i've already tested the injector resistor with an ohmmeter, simple device. So now am I to check wiring continuity to the ECU, repeat the voltmeter tests at the ECU from the TSRM, and then swap ecu if those check out normal?
I am out of other ideas at this point.

Are the injector's grounded at the correct location and is the ground clean and sound?

I've had issues like this on a couple MKIIIs and it's always something different. Wiring harness, CPS drive gear installed 180? out after a rebuild or on a new (reman) unit, igniter and coil pack grounds were the issue in all of those cases.

You can measure the timing of the injectors against the crank pulley with a timing light. If you don't have an adjustable it's just a light show and you have to guess what the timing is but nonetheless if the injectors aren't getting power or don't have a good ground you shouldn't see anything. You just connect the pickup to the injector's wiring clip, shine the light on the markings on the balancer and while someone cranks you watch for a consistent pattern. I think you'll be looking around the 50? range but I'm not positive, I haven't done this on a 7M. The timing isn't important though, this SHOULD show if the injectors have a solid signal.

This is a great tip! Thanks, I will try it.

Thanks for the generous donation! Made my day. I think some people think this is my site and the advertising dollars come to me... it's not and sadly, they don't. I'm just a volunteer. Thanks again.

One more thing you might want to check is that the ECU is getting a signal of >11v+ at the STA input when the starter is cranking.

new ECU, new game
 

OK, had a spare ECU for an automatic transmission, same grey plugs. I have a M/T with a converted A/T harness, so I swapped the ecu anyway and it cranks fine. STA actually not checked once it cranked ok. Other voltmeter tests for the ECU and the "ignition on" were all correct, including all 3 injector channels, KSU signal, MREL, and ISC1-4.

Now the symptoms are back to before the explosion: With injector resistor connected I'm getting something. It chugs for a second and sputters, seems like it will almost go, but won't start all the way. When it was doing this before I managed to get it barely running a a few times and that's when it exploded and stopped, so I'm afraid to keep trying to start it without a clearer idea of what is wrong. Timing is set approximately according to the TSRM instructions for installing the CPS, which usually is enough to get it started.

Timing light didn't work in the injector wire. I put the magnetic pickup that normally goes on a plug wire over one of the two wires going to injector 1. Didn't trigger the light with old or new ECU.

Timing light does flash on plug wire #1, maybe not perfectly regularly, but better with the new ignitor than with the old ignitor, I think. STill not sure the spark is 100% regular. checked coil resistances - all ok. Plug wires (MSD) checked a month ago - some were close to 20K ohm, which is in spec but barely. I have some old stock plug wires left, as well as stock injectors and stock AFM, and an extra coil pack.

1)Should I focus on trying to get the timing more accurate by having someone crank while I check timing? Or do I need to double check anything else before going further. Not sure about these RC injectors, Lexus AFM, AFPR: haven't worked with this setup before.

2) Should I scrap the setup and go back to stock AFM, injectors, and plug wires just to test it? That's of course a couple of hours converting, and a couple more changing it all back later, but well worth it if I learn something from the exercise. Actually, I crimped the new injector pigtails and heat shrunk the connections, so I can't really go back to stock injectors very easily. I could make a adaptors of the old injector pigtails and some crimp on female terminals, I suppose. I'd do that if it would help.

3) should I go back to stock on just the plug wires, maybe swap the coil pack?

4) Should I continue with the A/T ECU? How much difference will it make?

At this point I don't want to shoot from the hip. I'd just be picking at random from the list.

Thanks.

I would start with swapping the electronic part of the old AFM into the Lex AFM. The electronics are the same and you know the old one works I presume.

I don't understand your reply about the STA signal. This signal is important as it tells the ECU that the car is being started and despite the airflow being below the specified threshold for the emergency fuel cutoff that it should power the pump and injectors for a set period of time. At least this is my understanding of how it's applied in the 7M-GTE's case. The timing light on the injector wires is to ensure that they are getting a proper signal when cranking. If you know it's getting fuel then this probably doesn't matter.

As I reflect I feel that the explosion may have been either due to the ignition timing being wildly off from the mechanical timing OR the injectors are firing way out of order and fuel is pooling in the runners until that unfortunate spark lights one off. The injectors are low impedance right?

I wouldn't worry about keeping the other ECU in place. I don't think that's the issue... I could be wrong though.


I'll go back over this thread in its entirety tomorrow, think about it for a bit and try to see if I can think of anything specific which we've neglected. Have you verified that the injectors are connected in the proper order?

new inspection to-do list
 

Yes, though the part number is different by one digit and might not be eletroncially identical. I have to supra part in the lexus body now, I will try that swap.

Ok, I didn't understand the STA function. I will check it. My only proof that i'm getting fuel is that it almost starts when the injector resistor connector is connected and not otherwise. I believe this takes the injectors on and off line. With my lovely assistant, I will also verify that pressure is over 30psi WHEN cranking.

both issues may have come to play, i think so. those are the two issues I considered: back fire or ignition timing. It sounded more like timing, too loud and crisp for a back fire, not a pop, but a boom. and a lot of protesting cranking, like the engine was kicking back at the starter. That isn't happening any more so I think the timing is at least better.

I feel the symptoms are different with the new ECU: It definitely is much closer to starting now, chugs in it's own for a second, so I'm thinking the old ecu was damaged by jumping it incorrectly. there was smoke and an ozone smell in the passenger compartment... Just a matter of whether to buy a new M/T ecu. Plan was to wait until I get it running before worrying about that. I will take the old ECU apart and inspect just to see if the board is burned.


I really appreciate your help. the injector plugs are long enough now that they could be connected out of order, but it would be pretty obvious. Only #5 and #6 are easy to mix up. I will verify continuity to the correct injector resistor pins per TEWD with a voltmeter. Also will verify that both leads to 1 and 4, 2 and 6, and 3 and 5 are in continuity with each other. Connection of each of the 3 circuits to the ECU was already verified with voltmeter yesterday.

FWIW - I wonder if air/fuel mixture could be way too rich. I have AFPR, A/F adjust screw on the AFM, and a bosch 'BOV' (recirculating discharge with stock plumbing). I have checked for boost leaks carefully, so I don't think that is a problem, but I might have been fixing boost leaks when the problem starting first occurred, before I screwed up the timing. Just another factor to consider.
Thanks again.

Ok, I didn't notice you had mentioned the smoke and burnt electrical smell previously... Wow, did I actually miss that? Check wiring too, more may have burned than than the ECU. The ECU is pretty well closed up, actual smoke is more likely to present from wiring or a relay. Do you know that you jumped the wrong pins? If so which ones? One big issue with burning wire harnesses is that the wire doesn't always burn to the point that continuity is interrupted, you often get shorts across other wires where the bundle is wrapped tightly together... not fun to track unless you can narrow it down by locating two devices which are not both operating and share the same harness.

No need to buy another M/T ECU, the A/T ECU should function the same. I'm pretty sure there aren't even any wiring changes to be made.

The fuel mixture would have to be obscenely rich to prevent the engine from at least chugging for a minute after a cold start. Especially if it's been allowed to sit long enough for the excess fuel to evacuate. I'm talking rich to the point that the injectors are leaking. Now, that said, it might behoove you to pull them and test them as specified in the ECU to be sure they're not leaking and are opening when voltage is applied. The shock of the combustion in the intake could damage injectors but I don't think it's very likely. If you think the cylinders are flooded then pull the plugs, crank the engine for several seconds and let it rest for 24 hours to ensure that the vapor has had time to evacuate the cylinders.

The electrical components in the two AFMs are identical and present the same scaling when tested in the same housing. They are completely interchangeable. The housing swap generally requires tuning. I do not recommend using the air bypass screw for this purpose. Its scope is full spectrum and the airflow signal needs to be tuned selectively for the best performance and to ensure that you're not creating any lean spots or washing a cylinder. Do yourself a big favor and invest in a fuel controller and a wideband controller. The wideband is an invaluable diagnostic tool. Innovate Motorsports makes a couple very inexpensive controllers that are very well rated and easy to use.

A boost leak isn't going to cause a problem like this... You'd have to have a 1" or larger hole in the piping to see something this bad. A leaking BOV won't have any affect on the operation of the engine when not boosting.

You haven't made any modifications to the AFM or sprayed any type of cleaner on the sensor, have you?

I haven't gone back through the thread yet and it's been a long day. I will try to make time tomorrow. Hopefully we can get this sorted out in the next couple days and have you on your way. Open and inspect the old ECU as you said. If any of the traces or components are burnt see if you can identify which pin(s) on the harness are related and thus limit the amount of time you may need to spend diagnosing the wire harness.

smoke
 

checked wiring - I pulled the dome fuse because there was a question of a minor short in that circuit. Otherwise, no short to ground. and so far haven't found any wiring faults doing voltmeter tests on the ECU. Here's what I did: jumpered the car with positive to positive and negative of the other car to the positive alternator output. Don't ask me why, in do know better. blew a fusible link and a a fuse, replaced these and had headlights coming on but not popping up, and not turning off with the headlight switch off. When I finished testing all the circuits for shorts and replaced fuses the lights worked normally and it was behaving pretty much normally, minus the dome light fuse, except the ECU, which I replaced. Now seems okay except the starting issue. Really no idea why the lights went haywire or how they resolved.

Not flooded - tried it several days, same result. Also, I usually disconnect injectors or injector resistor and then crank with throttle open to clear a flooded engine and that isn't helping with this problem.

I have a wideband :D
Fuel controller is the next purchase. once it starts.

No mods to the AFB and no cleaner on the sensor.

Don't sweat the time frame. I'm a weekend warrior mostly, but your rosey prognostication gives me hope, thanks. Couldn't work tonight, it's day by day.

I've been through this with a couple MKIIIs and I know a few others who've been there too. It's a royal pain and typically is due to more than one point of failure or something which the ECU and the TSRM don't know how to diagnose (such as a short in the wire harness across two lines such as Vc and Ks.... been there, rebuilt the whole harness). With diligence you'll find it it just takes patience and a lot of deep breaths.

Now that you have an ECU that you're more confident in in place you should check for error codes regularly to see if it sees something we haven't.

All tests above are completed
 

Okay, I think I've covered all your questions so far.

I verified fuel pressure, set it to 35. Only issues is that may AFPR leaks pressure a little too fast when the ignition is off. I don't think that is keeping it from running.

My injectors are correctly wired to both the ECU on one side and the injector resistor on the other side. THe injector resistor has a good ground.

My ignitor works, it is wired to the correct coil packs and plugs, and the plugs all fire in pairs as described in my write up on the first page of this thread. I hope what I write up is the correct wiring for the 7MGTE - it was the best I could figure from available sources.

I pulled all my plugs - one had a cracked ceramic insulator, don't know if it was firing. others were intact but ALL PLUGS WERE both WET with gas and black with soot, and there was a thin layer of gas on each piston.

My intake air pipes were sooty from sporadic intake runner ignitions.

My original ECU still doesn't run the car, though it cranks. It had no evident burned circuit board components when i took it apart. The new ECU still almost starts the car, it chugs along very rough for a second or two.

I swapped the electronics on the AFM. I'm using the one that came with the Lexus throttle body.

Any thoughts now?

injectors?
 

I just remembered i might have put in the rc 660 injectors when it stopped working. Would that be enough to flood it?

I just remembered i might have put in the rc 660 injectors when it stopped working. Would that be enough to flood it?

I'm probably not going to be here much for the next couple days. My grandfather went into the hospital and was diagnosed with a hematoma (sp?) in the brain. It's nothing they can correct and he was on blood thinners so it's just a matter of time. :(

Would you please set your crank to 0?BTDC, take the cover off of the CPS and post a picture of the internals? I'd like to see if it's clocked correctly internally.

The 660's would make for rough running and starting but it should still burn and not fire back into the intake plenum. I'm not saying it's not possible but I don't think it's very likely. Have you inspected the ISCV and the check valve to make sure enough air is entering the manifold when the throttle is closed?

OK good luck
 

I'm terribly sorry for your grandfather. I'm a medical doctor and know exactly what you are saying. I'll post here as a sketch pad in your absence in case anyone with a similar problem stumbles on the thread. Between the cam timing and trying the stock injectors I think I will have my answer. thanks.

Resolved!
 

It's running! A handful of problems, but the primary issue was mixed up wiring from the CPS. I found two reversed wires before, as posted, fixed those, but didn't notice the other two were also reversed. fixed nose and it started, running on two cylinders.

Then I was able to sort out the wiring from the ignitor to the coil pack. the wiring from the harness to coilpacks 2 and 3 were reversed in trying to check the wires last week.

This was further aggravated by 650 injectors with the lexus AFM mod. I think I will need a piggyback ECU to make that run well, so I went back to stack injectors and AFM for the winter to get the bugs out. I believe you were right though, the lack of starting was not primarily from too much fuel, but I don't think it helped.

But the original problem leading it to sound like the valve timing was off, and causing detonation, backfiring, etc, was the CPS wiring. Mystery solved.

I will recheck my ignition wiring post to make sure it matches what worked.

THANKS for your help. Hope things went as well as possible with your family issue.

Finally! Excellent! I'm just bummed it took so long to sort out. I really need to take pictures of the CPS harness on the next pre89 and 89+ that I end up working on.

With the injectors and the Lexus AFM you should be fine if you pull 10% off the mainscale whether it be with an adjustable fuel pressure regulator or a fuel controller. I would wait until I had a fuel controller though as you're still going to want to fine tune the rest of the fuel map.

Everything with the family was as I expected. He passed on quietly after a couple days, most of us understood what was going on and had no issue but there are a couple family members who are going to need time.

Congratulations on getting it back together! I do hope you'll keep us posted on your progress... As with many things you see a lot more horror stories and than success stories on forums.