5MGE in MA61 Problems

[LezSpaz]

Some of you may have seen me ask in different parts of the forum about what's going on. So I'll put all the things I've noticed wrong with the car.

The car:
1984 MA61 Celica Supra
1988 5MGE - From MX73 Cressida
Manual

Parts swapped in conversion:
Engine
AFM
Cressida wiring loom adapted with Cressida ECU to car
Ignitor and Coil
Thermostat
Coolant temp sensor
Spark plugs

MAIN:
*Erratic Idle when cold
*VERY low power on low revs (need to rev and ease clutch at about 2.5k RPM or it'll stall)
*Stalls sometimes when no load is on the engine (So when there is no force to help turn the engine, due to it not being in gear)
*The stalling usually happens right after you let go of the accelerator
*Seems to run crazy rich (Especially after about 4k RPM sometimes spews unburnt fuel in a big black cloud)
*Exhaust Leak
*Misfiring? Sometimes sounds like it, I haven't ever heard a car misfiring in person though, so am not 100% sure

SMALL:
*Fuel gauge doesnt work sometimes (Shows either nothing, 11L-14L, or it'll show the correct amount)
*Fuel pump whines at idle (may sound like a turbo spool when accelerating, unless that was something else)

Theories:
*Idle Speed Control Valve can't close or is gummed up
*Dashpot problem? (The valve that basically makes sure the air fuel mixture is completely burned on deceleration)
*Vacuum leaks
*Blown Headgasket? (Please tell me it wont be this...)
*Clogged Fuel Filter
*Bad Injector?
*Bad fuel pump?

Basically, I just want to get this car idling properly and for it not to stall most times when I move my foot off the acelerator to brake (while clutch is in or gear in neutral, I basically have to heel toe in emergencies). Also don't want to have another incident of being at a red light next to a cop and having my car do douchebag revving...

I'll post up a youtube clip of the weird idle probably sometime tomorrow night

Any theories, experiences or personal tips would be greatly appreciated.

[LezSpaz]

Damn, forgot to add what I've checked:

ISC Valve: Took it out, cleaned it, did a bench test. Left it in the closed position after testing, thinking it would reset back into whatever it needs. Put it back in the car, the car wouldn't idle at all. So ISCV was closed and did not open after ignition. Is that normal? Anyways, so after that, I took it out, opened it, and put it back. Now it's back to its weird idle.

Dashpot: Don't actually have decent access to it at normal operating temp. Mine runs under the throttle body and ends up somewhere near the lower intake plenum. I thought this could be the cause of the car stalling while I'm driving and letting go of the accelerator and putting in the clutch.

Vac Leaks: So I've gotten a bit of hose and tried to listen around the vac ports on the upper end of the motor, but I can't really tell what I'm looking for. I can't hear any hissing except for what I assume are normal engine noises.

BHG: Going to run a compression check once I find where my bro put the spark plug tool kit.

Fuel Filter: Going to buy a new one soon anyway (within the week)

Injector: Only have really just put injector cleaner sometimes. Doubt that'd do a thing. I'll check it later on, once the things that are easier to get to have been checked.

Fuel Pump: Don't know how I'd check one, other than getting a new one

[CrUZida]

Ensure the TPS is set correctly. Use the TSRM. Only worry about setting up the IDL to E2 setting (make sure it goes open circuit as soon as the throttle is cracked open). Ignore the rest.

Make sure the throttle plate is 100% clean and 100% closed.

Make sure there are no leaks between the AFM and the throttle body (its common for the rubber couplers to leak)

Make sure the timing is set correctly (bridge TE1 and E1 to put ECU into diagnostics mode first)

The ISCV wil reset itself every time you turn the motor off. So if you wind it all the way out and start the motor up, it will be confused, you'll have to turn it off, the ISCV should reseat itself to maximum open, then should be ok. You may have to repeat this a couple of times to get it to fully seat itself.

[LezSpaz]

Thanks CrUZida!

I worked on it bit by bit over the past few weeks. So the TPS was way off, and I adjusted it, and it no longer did a long up down idle. Then I while cleaning the throttle body again, I noticed the accelerator cable was ever so slightly loose. So I tightened it and it greatly improved initial throttle response. Then today I check the timing, and it was set to 0 Deg BTDC rather than 10. Now it runs practically like a new car (No more stalling as far as I can tell)! Took it on the freeway onramp, and there is SOOOOOOOOO much more power. Just waiting until the next dyno day to get some figures!

The fuel pump is still pretty whiney (normal for walbro? Don't know what's in mine), and the fuel gauge is still stuffed. Exhaust leak is still there, so if anyone in Vic has a spare 5MGE exhaust manifold, I'd be VERY interested Otherwise I'll get some extractors for it

[ma615mgesupraboy]

ok guys got a problem for ya to help me with the old gril has a 5mge and for some reason when i test the spark theirs no spark when cranking but as soon as u stop it lets a spark off what have i done wrong and how do i fix it ? oh i'm using the 5mge auto ecu and thinking thats the problem as the car is 5 speed

[CrUZida]

Thats definitely not the problem.
My guess is you have something losing +12V when the key is in START.

Disconnect the trigger to the starter motor, get someone to hold the key in START, and go around checking everything for +12V

[ma615mgesupraboy]

i been told it could be the coil or a crank sensor doing it

[LezSpaz]

I'll have to revive this thread again for the same car, but a different issue (most likely electrical).

I hadn't driven this car as a daily since about April, yet I'd start it every now and then, and drive it about once every 3 weeks for a short trip. Then my daily died and I started driving the MA61 again, since about two weeks ago.

On Thursday last week I noticed that the car wouldn't crank unless I pop the accelerator a few times then turned the key.

On Friday, it wouldn't crank at all unless I held it at WOT and turned the key at the same time, and even then it'd take a bit longer to start (not longer than a normal car, just longer for my Supra).

On Saturday morning I try holding the throttle and turning the key, nothing. I clean the battery terminals, nothing. I try a new battery and still nothing.

I had a similar issue a few years ago before I got it registered, that the positive wire for the starter motor came loose, and I checked the leads as best as I could without getting under the car. (had a torch, mirror and a feel around and everything felt secure). Even then, though, I didn't hold the accelerator to start it previously.

I'm pretty confused about this. I tried getting error codes from the ECU, and I used to usually get codes 41 and 43, but now I just get a quick steady pulse. Like 1010101010. The pulse is quicker than when I used to get those other codes.