here is a video from this am
http://www.youtube.com/watch?v=lUgZ2nKX5O8
after this video i am replacing the cps with another due to the oe one used in this video had cracked wires.
also i plan on trying a new tps again and see if it helps????
here is a link to some info i found useful.
www.autoshop101.com/forms/h23.pdf

it is almost like the ecu is cutting the spark or injecors (but the fuel consumption is pointing more towards spark). like in this link where it talks about the ecu cutting fuel when the igf signal is not back to the ecu from the ignitor from a serious misfire.
any new ideas from this info???

so i am ordering a wideband. i have seen other threads where this type of symptom is caused by overfueling.
so what would cause over fueling? tps, afm/ boost leak,.....??
any suggestions on this would be nice.

AFM, boost leak (will only cause real issues at higher loads), excessive fuel pressure, fault in the knock sensor circuit. The TPS is a less likely candidate.

thanks for hanging in there cre. the weather is going to be bad for a little while so going to have to wait for a little bit.

well i ran out of $ so no wideband for me yet. the thing runs almost normal with the hac unplugged. but drivability with it unplugged is crap. has a stumble between 2000 and 2500 like a deadspot.
i am going to do some more digging and see if the hac is messing with the volts to the afm, tps, ect. i am going nuts. hope to figure out soon.

here is the updated (clearer) explanation:
1987 7mgte rebuilt motor, head milled, oe hg, arp studs torqued to 80 ft lbs and were retorqued after heat sequences, 440 injectors, stock 7mgte afm housing and meter, 3" doenpipe/full exhaust, water to air intercooler, ign timing at 10 deg. wiring to the tps, afm, ect, hac have all been rewired with new wire and to speck on the tsrm for a 1987 7mgte ( http://www.turboninjas.com/mk3supra/...7_Mk3_TEWD.pdf )( i thought the original wiring was to blame), cps is installed correctly and triple checked.
~6300 ft elevation
engine swapped into 1980 toyota 4x4

-engine starts and idles great at ~800ish rpms. fuel pressure at 32psi at idle and fuel up vsv line hooked up to the FPR and fuel pressure changes to 40 psi when throttle applied.
-ign timing with jumper in place it is 10 deg btdc at idle and at operating temp.
-at idle -17 vacuum
-PROBLEM: with light throttle (very slowly applying throttle) revs smoothly up to 2800 rpm. once 2800 rpm has been reached if throttle is applied over that the motor will not go past the 2800 rpm and bog down to 2000rpm and act like/sound if you were to exhale all of the air out of your lungs and continued to blow more out but cant. while doing this it will make a stumbling noise and some popping noises, also you can hear the turbo spooling through the exhaust and occasionally a backfire pop through the air filter if the throttle is WOT.
this hesitation stays from the 2800 rpm amount of throttle through WOT. up to 2800 rpm the vacuum is -15 or so and when hesitating at WOT it will go to 0. once the hesitation starts it continues through WOT and when it is hesitating the more throttle from the begining at 2800rpm to WOT the vacuum gauge acts as if it is operating from -15 to 0 on a cable attached to the throttle.

if the throttle is revved up like vroom vroom vroom vroom sometimes it will overcome the problem and rev up to redline like a normal motor.

this happens at idle and even worse during driving.
when the hesitation starts at while driving it bucks violently and fells like some suspension is going to break a ring gear, u joint, tranny etc...
during driving if you get past the hesitation and are at cruising speed (under 2800 rpm) if you hold the throttle steady and the speed catches up to how far the throttle is open it will feel like a switch, it is off power and will accel back up to where the throttle is depressed (the off power feels like when you would hit the cancel switch while on cruise control).
if i open the throttle enough to get over the 2800 rpm hesitation the truck will act like i am flooring it (WOT) even if the throttle is barely cracked and accelerate like crazy until it catches up with the speed and then "power off".

here is the link to my youtube with the videos
http://www.youtube.com/user/cctool/v...ew=0&flow=grid


what i have found through testing.
***with the tps (only) unplugged:
-no dash cel light on.
-with jumper in and engine off and key on cel code 51 illuminates.
-slightly higher idle
-i can rev it up over the stumble by working the throttle open closed open closed etc...to redline
-can rev slowly up to 2800 rpm then above that to WOT it will bog down and drop to 2000 rpm while doing this it will make a stumbling noise and some popping noises and occasionally a backfire pop through the air filter if the throttle is WOT while not under load in driveway.

-reset ecu and no cel stored
***with afm (only) unplugged:
-dash cel light as soon as motor is started
-key on engine off cel 24 and 31
- i can NOT rev it up over the stumble by working the throttle open closed open closed etc...
-will not rev past the 2800 rpm at all.
-can rev slowly up to 2800 rpm then above that to WOT it will bog down and drop to 2000 rpm while doing this it will make a stumbling noise and some popping noises and occasionally a backfire pop through the air filter if the throttle is WOT while not under load in driveway.

-reset ecu and no cel stored
***tps and afm unpluged:
-dash cel light as soon as motor is started
-key on engine off cel 24, 31, 51 codes
- i can NOT rev it up over the stumble by working the throttle open closed open closed etc...
-will not rev past the 2800 rpm at all.
-can rev slowly up to 2800 rpm then above that to WOT it will bog down and drop to 2000 rpm while doing this it will make a stumbling noise and some popping noises and occasionally a backfire pop through the air filter if the throttle is WOT while not under load in driveway.

-reset ecu and no cel stored
***unplugged hac (only):
-no dash cel light
-key on engine off cel 32
- i can rev it up over the stumble by just giving it more throttle
-will rev past the 2800 rpm. and seems to rev up past the hesitation a lot easier than with it plugged in.
-it does not hang up like when it I is plugged in

-reset ecu and no cel stored
***with ect (only) unplugged:
-dash cel light as soon as motor is started
-key on engine off cel 22
- i can rev it up over the stumble by working the throttle open closed open closed etc...
-can rev slowly up to 2800 rpm then above that to WOT it will bog down and drop to 2000 rpm while doing this it will make a stumbling noise and some popping noises and occasionally a backfire pop through the air filter if the throttle is WOT while not under load in driveway.
With all unplugged (afm, tps, ect, hac)
-It will not rev over 2800 rpm. And ign timing will not advance and stays at the 10 deg
***With the intercooler pipe from the turbo disconnected before the intercooler to simulate a blown hose. It
-no cel
-it Idles irratic 700-900
- -9 vacuum, and smokes like crazy,
-- i can rev it up over the stumble by working the throttle open closed open closed etc...


****with the HAC unplugged the hesitation is only a little noticeable at idle/not driving.
once it is over the hesitation Driving at 2200-2400rpm. It runs and drives fine. I can hold the petal steady in say 4th gear and about 3200 rpms and the petal stays still and the speed matches without any cut out. But if it is below 2800 to 2200 rpm while driving the throttle sucks. Will not hold speed and cuts out.


no feed voltage change to the afm, tps with the hac unplugged.

That's really weird, just watched some of the videos & it almost sounds as if IDL and E2 are bridged on the TPS causing it to drop into fuel cut RPM test mode like shown here http://www.cygnusx1.net/Supra/Librar...ction=FI&P=125

Have you tried a substitute ECU at all? And there's definitely no chafed wiring causing IDL and E2 to short at the ECU pins? Hope you get this worked out

EDIT-: Especially this video, the revs are even hanging nearly the right range for it to be an IDL/E2 short http://www.youtube.com/watch?feature...dl693JyvI&NR=1

thanks for the reply. yes i have tired another ecu. i have a spare. the tps has been rewired with new wire so i dont think it is that unfortunately.
but yea it seems like the afm is telling the ecu it is taking more air than it actually is.
or the tps is telling the ecu that it is floored. this would explain why the motor acts like it is being floored under load ( with the throttle body barely cracked and the motor continuing to rise in rpm like i am flooring it.
also while having the throttle barely cracked and rpm like 3000 the vacuum will be at like 0 but i can hear the waste gate open and the woooosh from that. but it is not boosting.
i really wish i had someone within a 4 hr drive that knew stuff about this motor or had a supra to help diagnose the problem.
but i will look back and check out what you suggested. thanks

Yeah I wish I was able to get over to have a proper look into it, chewy electrical/electronic faults are well, maybe not my forte, but I love working through them for some reason (must be sick in the head lol) & I'd have got my '89 round for some swap-tests too :(

I've found even new rewire jobs can cause issues sometimes, would def be worth checking for any kind of short at the ECU pins for those TPS terminals if only to rule them out 100%. Also, what sort of wire was used for the rewiring you did? I don't know how sensitive the Toyota ECU is to RF or EM interference but could be worth making the TPS wires twisted pairs &/or wrapping them in foil to eliminate any possible outside interference from other nearby circuits seeing as they deal with fairly low voltages. Obviously you know the knock sensors are very very sensitive to this sort of issue & their wiring should be decent shielded/twisted stuff too (would imagine they're OK anyhow as interference there seems to throw a code 52 and you don't have that at any time right?) Depending how much of a pain it would be, I'd say maybe try to isolate all the low voltage sensor signals from the rest of the loom or at least any sensor wiring that was re-hashed for the transplant.

Another quick check on the TPS & wiring is to block the throttle open slightly, switch on the ignition & run a diag check. Should throw a 51 for no IDL signal at power up. Maybe covering old ground here but then I didn't notice if this check was done in previous posts... Damn I wanna look at this, it's screaming fuel cut at me....

thanks for the response. i used new automotive grade 16 gauge napa wire. and i have tested the tps wires at the ecu on ohms and volts.
i had a 52 code when i first got it running, i rewired the knock sensors with some shielded coax like the write up online.
yea i get the code 51 with the jumper in and opening the throttle at the beginning and the idl opens when testing the tps wires.
the factory tps wires do not have shielding on them. only the cps, o2, knock have a shielded ground around them.
i have preformed the fuel cut test like in the tsrm and the problem i have acts different in person than the test acts.
but i have never heard fuel cut in person so it is hard to compare it to it.
i am going to have a friend come over and help me in the next few weeks. he has a snap on super computer diagnosis tool, hopefully it can read frequency and maybe even o2 like a wideband?

it is getting hard to remember all of the stuff i have tried. between the wiring checks, sensor/parts checks, and troubleshooting.
i will look into the tps and the wiring again.
i hope i can check and see what the afm reads with the hac hooked up and with it unhooked and see what changes.
i originally thought it was the tps but have not been able to prove it was the tps so far.

i enjoy wiring motor swaps as well and diagnosis. but this one is killing me. it has been over a year.
i tried checking the vf signal at the diag port but i dont fully understand where to go with the results i get.
i have wired multiple motor swaps from tacoma 3.4s to chevy 4.3s to lexus v8 to ford i6s. so i am the guy people go to for wiring problems but i have not been able to figure this one out yet.......

That's half the problem with long running problems like this, you can end up running in circles if you forget what's been done. If something takes more than a few days to "nail" I like to start a sort of diary of what was tried, what readings of things were on a certain day, what happened when I did a certain thing/disconnected X sensor or Y plug & stuff like that... with any luck the computer will be able to get things straight anyhow, sounds like all the wiring should be OK... Hey here's a leftfield one, have you tried running it for a short time with the alternator unhooked (belt off not just unplugged)?

Like I say rather left of field and can only try this for one or two pulls from cold as the water pump would be down too, but I have heard of an electrically "noisy" alternator causing problems as it spun before...:dunno:

i have been working on it some more with a couple of toyota friends. we went back over everything i have checked. and found everything we checked to be in spec with the tsrm.
we hooked up a snap-on scan computer as well. it threw the code 32 (HAC) since i had it unplugged so i could drive it to town. the tool said that with the hac unplugged the ecu will shorten injector duration. so why would it run better with the shorter duration like when i have the hac unplugged? what trims how long the injectors open for? could it be like i previously thought, with a rich condition and flooding the cyl with too much fuel to burn with the amount of air?
i went over the tps again and i get all good signals from that at the ecu. the volts slowly increase when i open the throttle. the idl opens at slight throttle.
:offwall:
i would like to have another harness to try? might be a bad wire in the harness that test ok but wont transfer the continuity when it counts etc...????

well hell.
i got a new oe style high flow toyota pump (AIRTEX #: E8119). but it flows more than the fpr can handle and it runs about 38psi on the rail and does not raise when the vac line to the fpr is removed. so ??? motor still runs the same...not good

i got a saab/audi bov still runs the same....

i tried putting a empty soda can in the exhaust tip to see if the exhaust was too free flowing and the turbo was spooling too fast/much.....ran the same.

shit. gonna try a few more things then maybe pull the turbo and check it out (even though it spools and does not make noise)???
then pull the entire harness and do a wire by wire recheck or rewire with new wire???

any more suggestions?

well i pulled the motor harness and checked every wire. i found the shielded o2 wire was grounding to the inner wire. so i fixed that. everything else checked out good. so shit.
i unplugged the knock sensors at the ecu and it threw the code. and made no difference. i already did the rewire and that fixed the original wiring cel code.
as of today i started it and it was hard to get to fire. even ran crappier than normal. it still backfire POPs into the intake manifold when it is doing the hesitation.
also i unplugged the oil pressure wire to the ecu and it made no difference in how it ran. also my oil pressure is reading high or it at idle (so i might have a new oil pump in my future if i dont light this thing on fire only to piss on it to put it out :mad:
on this thread http://www.celicasupra.com/forums/sh...issues-bucking!
it kind of sounds like my shit and he replaced the afm with a maft and gm meter.......
i think i am going to try a new afm and see if that works???? i have tried 2 other used ones and to no avail.

could i go the maft rout or should i maybe go for the maft-pro???? i think my main problem is the tccs system being retarded somewhere in the mix.
the maft pro would basically replace my tccs ecu correct???

thanks for all the input.

The MAF-T and the MAFT Pro and the MAFT Gen II are all made by the same developer. They're piggybacks which modulate the TCCS' input and output. The MAFT Pro and the MAFT GEN II are very feature packed and an excellent value for what they provide.. essentially standalone functionality on a piggy back budget. The MAFT Pro is about the same as the MAP ECU... They're all just piggy backs and none of them replaces the TCCS.

I've wondered for a long time now what the heck is up with your system... It's not right... to a degree that it feels like it should actually be obvious where the fault lies. I need to re-read through the whole saga to see what's already been done though before I just spend a couple hours repeating everything you've already done. But, not tonight.

getting back at it
 

well been busy blah blah blah....
it is warming up here so i got a wideband o2 installed. here is the video.
i have a friend who is pushing that it is the turbo?? not 100% sure if i should go that rout yet.
here is the video with the wideband.
http://www.youtube.com/watch?v=pGTOPFjHf5Y
also when i go to start it now it is reluctant to start. i have to pump the throttle and it pops and barley starts from a cold start.
i have tried 3 used afms. autozone can not get the direct replacement for the supra but they can get the one fro a ls400. these are the same electronics except just the tube diameter correct? so i could try that and just swap the electronics onto my supra alum tube body?

would the knock sensor throw a code of any kind if it is detecting knock when it is running?
i am almost certain it is the injector duration being cut from the ecu....since i can hook up a timing light and see where the ignition is when it is running. and it is not being cut or retarded. or the intake cam is out so the ign when it is going advanced it is sending spark out of time?? other than this retarded problem...
i cant hear any knock or ping. i am putting premium fuel in it tomorrow to see if that helps at all.

Other than when warming up and at idle the ignition will almost always be advanced to one degree or another. If knock is detect no code is presented. The code is only presented if the ECU feels the sensor is damaged or providing erratic information (see: damaged).

A grounded OX signal isn't going to cause a severe shift in fueling. After a brief period the ECU would determine the signal to be faulty and go into open loop operation and ignore the sensor altogether.

The fuel pressure not increasing without vacuum indicates a bad FPR, vacuum leak or restriction from the couple times I've dealt with it. Try putting a vacuum pump on it and check the fuel pressure.

i have a pressure gauge on the rail. with vac at idle it is at 34psi and without vac it is about 40. also when it is hesitating the fuel pressure is at 40 psi on the rail.

no difference with premium fuel, valve timing is spot on with cams and crank
if i hook up a timing light (without the jumper in for setting base to 10deg) and slowly rev up the motor i can watch the crank mark move up to around ~35-40 (guesstimate) deg advance when i rev up the motor slowly.
at the beginning of the hesitation the ign advance will retard to around ~25deg or so.
no difference in the timing advance with a knock sensor unplugged.

i understand that the wideband O2 will read lean even if the injectors are spraying the correct fuel at the correct time, but if the ignition is not there and the combustion does not turn the O2 into CO2 then the wideband will read the amount of O2 in there and not read the unburnt fuel. i have a feeling that this is what is happening when the hesitation is going on. i just need to figure out why the ecu is retarding the timing???

with a stethoscope on the injectors i can hear them firing at a nice even pace at idle and with slight increasing throttle they increase the ticking accordingly. just as it begins to stumble the ticking slows WAY down and becomes slower than when the motor is at idle when the stumble starts and continues.
if i rev it above the stumble they are ticking super fast (as they should be at high rpm)
so i am going to look back into reasons why the ecu reduces injector duration....like the main sending units-- afm/air temp, knocks, ect, cps,_____????
i think now i should be looking more at reasons for the ecu to cut injector duration vs the ign timing

Have I mentioned before that your car makes me feel like a basket case?

yea this motor makes me feel like a jackass. i am loosing my mind. out of all the motor swaps i have done and this is the first one i did to my own vehicle and it does not run, WTF. i feel like screaming every time i think about this motor.
i am going seriously insane.......:crazy2:

Are you still running the same wire harness you started with? It was shortened right?

yes same harness. the o2 sensor shielded wire was grounded from the inner wire to the shielded outer wire. in fixed the short and it tested ok.
i tested all of the other wire for continuity and all is good. i hope to look some more at it this weekend.....any specific places anyone thinks i should investigate?
i am going to replace the cps plug with a new weather pack plugs.

Okay, and I can't find mention of it in the thread, did you try another ECU? I'd be inclined to try another harness and ECU despite test previous results.

yes i have 2 computers. it does the same thing with both.
i would love to try another harness but i need to find one first.
today i cut off the cps plugs to put on the new weather pack ones and the wires on the harness side all have corrosion (green crap) inside of them under the insulation. i was unable to install the other side of the new plug due to i grabbed the wrong harness prongs. so Tuesday hopefully will have them on.

still no difference with the new plug on the cps....
does this make sense to anyone else...if the wires are corroded the ecu would might not be getting the correct number of pulses from the cps causing the ecu to cut injector pulse?
i wish i could find out what the ecu is seeing.

I thought the ECU monitors three signals as a part of the equation you're talking about: IGt, IGf and IG- Unless they're all screwing up in harmony a code is bound to show up.... I could be wrong completely wrong though, I haven't had the pleasure of working with a TCCS where simply swapping out components as a last ditch effort didn't cure it. I would replace the wires along with the connectors. Corroded wire has a higher resistance too.