insane 7mge
 

someone help. after 20yrs of 88 targa top fun it cut a light pole down!! broke my heart. now i toof my 7mge and put in an 89 body. something aint right. WONT IDLE TIMING WAY ADVANCED. DO i need to use the distrubutor from the 88? that and injectors were all that wouldnt plug and play. I have invested a ton of time and several bucks trying to get me a REAL car to drive again. open for suggestions PLEASE

Will not idle
 

Did you check regarding the 1989 as to whether was a turbo. Did you install a 1988 Computer?
Has the harness been splice anywhere?

Will not idle
 

Did you check regarding the 1989 as to whether was a turbo. Did you install a 1988 Computer?
Has the harness been splice anywhere? Regarding idle. is it slow, fast, skipping hard to keep running.

Confused
 

Replaced engine control module. Only 2 items wouldn't plug and play. Distributor and fuel injeCtors were used from the 89 engine is an 88 both na

As far as idle its really low and rough staggering around 500rpm

This one has me baffled I've been playing supra for 20yrs. Set base timing, checked all plug wires. No vacuum leaks. Most recently when I started it and coaxed it to run just to operating temp, the exhaust manifold turned chery red!! Cat stopped up? Never has had that condition. Surely their isn't a difference in distributor from 88 to 89?? Or injectors??

Injectors may be different, there was a change at some point between low and high impedance, although i cant remember the details. Exhaust cherry red sounds to me like you have retarded ignition timing. Just to be clear, you verified your cam timing is spot on, then brought the engine to operating temp, and then set your ignition timing to 10 BTDC with the jumper wire in place?

Also, why did you swap any electronics? Did the 89 not come with an intact engine control system?

timing is retarted. distrubutor and injectors have different plugs from 89 to 88. reason for change. diagnostic port shows codes 24 and 51 intake air temp and a/c. timing seems to be advancing or retarted wit the jumper in place.

Well, if I remember correctly, you can't properly set your ignition timing with DTC's present. You will need to fix your CEL codes before proceeding any further, as your base ignition timing will not be set properly until you do.

When setting base ignition timing, it can't advance or retard- it is whatever you set it. When you remove the jumper from the diagnostic box, it should stay close to the base timing of 10? BTDC, but it may retard or advance by a degree or so.


89 is a very tricky year as far as engine / chassis wiring is concerned; there are several variations, and they aren't necessarily 100% compatible with earlier or later set ups. Your '88 should have used yellow fuel injectors; since you said that these injectors didn't plug in, I'm assuming you have green fuel injectors installed? The yellow top injectors are low impedance, green top are high impedance. Low impedance injectors require a resistor pack to function properly (your '88 had one, your '89 probably doesn't), high impedance do not.

Also worth noting, yellow top injectors flow 295cc, green injectors flow 315cc


So that I (and anyone else reading this) understand your swap correctly, you have an '88 7MGE with an '89 distributor, '89 fuel injectors, '89 wiring harness, '89 ECU, and all the '89 electronics on the fenders (ignition coil, AFM, etc)?

Awesome. So where is the resistor pack located? I have finally fixed code 24 by replacing the mass air flow sensor. Code 51 still present. You are correct 89 body and harness injectors and distributor 88 engine. I never dreamed this swap would be this tricky!! Your insight is greatly appreciated. I need my supra

I believe (by process of elimination) that the injector resistor pack is the metal box in the engine bay on the driver side fender. However, if you're using the 89 harness and ecu 1) I don't believe that there will be a plug to connect the resistor pack to and 2) you shouldn't need the resistor pack anyway using the injectors from the 89.

So which color injectors do you have; Yellow or Green?


After fixing the code 24, does your car run any better? Can you get it to idle without the exhaust manifold glowing red?

As for the code 52, does your A/C have freon in it? If not, that code has been triggered in my 88 I used to have for that very reason. I fixed it by placing a paperclip between the terminals of the low pressure switch, and again on the high pressure switch on the A/C system. This bypasses both of the switches, and acts like everything is ok in the A/C system. Be sure to not press the A/C button on the climate control unit with these jumpers in place, as this may damage your A/C compressor.

im running green top injectors at this time. i do have a empty plug near where a possible resistor pack may go. it does seem to run a little better with the new mass air flow sensor, but still nothing like it did in the 88. I have eliminated ISC. open for suggestions!! am I going to have to swap wiring harness??? im sure hoping not, but at this point beginning to wonder what to do

it will idle but only at 500rpm. the exhaust manifold isnt turning red anymore thank god. no ac unit in place so code 51 can stay there

Can't set timing with codes present.... (I think that means ANY codes). Properly deleted you will have no codes from removing the A/C.

so im open for suggestions. do i need to swap wiring harness distrubutor and injectors or what?? please someone help i need a supra

Did you get rid of the code 51?

I'd forget the harness, I'm pretty sure the impedance difference is enough that if the injectors and ignition were mismatched the would either not run or the injectors would burn up. If you tried running a pre89 wireharness with no injector resistor pack it wouldn't run either as there would be a break in the circuit. Does the ECU have grey plugs or yellow?

When you say you eliminated the ISCV does that mean you deleted it or just diagnosed it and are certain it's not suspect?

I haven't been following this thread so I need to go over everything before I can offer anything else.

just diagnosed the iscv working fine. I cant even get any real mechanics to touch it!!! I so dont want to giveup on this car, its not my 88 targa top car I foolishly wrecked after 24 yrs of loyal service, but it did belong to a dear friend who commmited souicide and his parents gave me the car to get it out of their life. Im starting to think my old friend is haunting it. 4give the delay in my response I had to walk away from it for a few weeks. i have thrown nearly 1000bucks at it radiator fan etc. It must live somehow!! I have both ecu"s the 88 is yellow plugs the 89 grey. I have kept the totalled 88 for parts, not that its doing me anygood! My wife just doesnt get it she wants me to buy some gas mileage generic pos. I just want to wheel that 4wheel independant suspension down a curvy road. So any and I mean ANY Suggestions of what to try will be greatly appreciated id like to make her run again just to show these fools who dont know toyota engineering that they are wrong. DESPERATE IN TN. Thnx

Ok, checklist time....

Code 51 - present or fixed?
Mechanical timing set properly - yes or no?
Injectors - yellow top or green top?
ECU - yellow plugs or grey?
ECU wiring harness plugs - yellow or grey?
Injector resistor pack - present or not?
Distributor - pre89 or 89+ (the pre89 model has a pigtail, the 89+ revision has the harness connector molded into the body)?
TPS properly calibrated - yes or no?
Any other error codes present?

These parts are not interchangeable... Toyota did a decent job at making the wiring stuff easy to follow... Grey plugs on harness + grey plug ECU + green injectors... Yellow plug harness + yellow plug ECU + yellow injectors + resistor pack (only present on the pre89 harness, if you don't have a spot for it you're running a GREY plug 89+ harness or you're looking in the wrong place). I wish that they did the same thing with the GE that the did with the GTE and changed the shape of the connectors instead of just the colors but really it should be pretty obvious if you've got the wrong color combo.