Car wont start hot

[carfanatic89]

87 7mge manual.
Ive been trying to find out whats wrong with my car for the last 6 months.
When my car is cold it starts easy and runs fine, till I get somewhere. Ill kill it, when I come back to it after sitting 20 mins and the engines still hot it will turn over but wont start. If im lucky I can get it to but it spits and sputters for about 4 miles then clears out. The funny thing is when its running after a cold start the engine cant take full throttle pretty much falling on its face, but once the engine warms up its fast as hell. I cannot find the problem anywhere.

I have tested just about everything in the car and everthing so far checks out. I just did a diagnosis on it and im comming up with 51. If it was the neutral start switch the starter wouldnt even try to start the car. I replaced the o2 sensor, TPS, pickup coils in the dis., wires, plugs, coil, fuel pump, FPR, fuel filter, air filter, and battery cables. I also replaced the grounding straps from the trany to frame, and engine to frame. and I cleaned the grounds comming from the bat. ground to the frame.

I also took a ohm meter to these, MAF, control modual and I also check the wires going from the ecu to the, tps, maf, control modual, o2, and injectors.

Nothing is wrong with this damn thing so why doesnt it want to start when hot. All the hillbilly mechanics around here know nothing about supras. I just want my supra fixed. please help me

[CyFi6]

when it cranks but wont start, check for spark, if you're getting none, you know where to go from there. If you are, check fuel. Most of the engine is mechanically in sync, so if it is getting spark at the right time, and is getting fuel, it should run.

[mrnickleye]

Sound like a fuel problem. Toyota had a real 'hot hard start' problem back then. The intake valves get very carboned up. Read and do this first. http://www.toyota-supra.info/forums/...injectors.html

It may fix your problem, and certainly is good for your engine.

You MAY have an electrical component that has a bad spot in it that is effected by a hot underhood soak (parking for a while, then trying to start engine). You will have to test parts and 'catch it' in the act.

[carfanatic89]

I might have found the problem I did the injector cleaner and carb cleaner in the intake, but it was still messing up so I started to pull the wires and plugs to take a look at them, see if the plugs revealed anything.

Everthing checked out till I got to the last two plugs. The spark plug wells where half filled with oil???? My valve cover gaskets are leaking AGAIN.

I replaced them about 8 months ago and stopped the leak. When they leaked last time it didnt cause my car to mess up, but I knew it would eventually so I replaced them and checked it every week for about 2 months with no signs of a leak. Im sure the day after the last time I checked it, it started leaking again. lol I hope this is it.

Oh and I had one other Q. When you adj the tps, do you set it based on how the engine runs or on ohm resistance. thanks

[btwilson86]

Set the TPS off of the resistance as stated in the TSRM

[carfanatic89]

Im really close to giving up on the supra, I got it back together and she's still messed up. I fixed the hot start thing. At idle it purrs like a kitten. If you gently press the throttle it will rev up and rev down like normal, but on the rev down if you give it gas to rev back up (like if you where shifting) it missfires and feel like the motor is boged down. If I give it full throttle, It acts like you turned the key off and wont rev up at all. The RPM needle just falls all the way to 0. (dies) A gentle throttle has more of a pull then full throttle. I dont know what to do know.

[Dan Swanson]

It looks like you have done almost everthing. What done to check for vapor lock and or lack of fuel? The fuel filter, the inlet air elecronics?the

I have drivena Supra like yours for almost 150K miles and have never had problem like you describe. I had the head off mine and can not get it running. I gave up and have posted a thread to sell it.

Sorry am not much help. I am sure that someone will come to your aid with a good idea.

Dan Swanson

[carfanatic89]

OMG I finally think I found the problem. I got this wild hair to open up the ECU and I found a resistor that was burned up. Im so happy words cant even begin to describe. I had to stare at the ECU for about 10 mins before I saw it. I literally jumped out of my car and ran around the parking lot. lol All the others are blue and the one burned up is white with black burn marks under underneath and from the edges of the resistor down the wires to the circut board. Here a pic my cameras kinda fuzzy but you can see the difference.

[carfanatic89]

What do I do now. I don't know anyone around where I live to fix this, should I try a computer store? I would like to fix i myself, but I dont know how to solder on circuit boards. Or take the old one off. As a matter of fact how is anyone gonna know what kind of resistor it is. I kinda dont want to by a used one from a salvage yard, it might be in the same condition this one is in, and I damn sure dont have 500 for a refurbished unit. Any advice welcome.

[CyFi6]

Try to get a clearer picture of the resistor, or tell us the color bands on it. Using that you can find the resistance. Then ohm it out and make sure it really is bad. Im sure a computer store would be able to do it for you, it isnt difficult, and you can just get a replacement resistor of the same value from anywhere like radioshack. If you cant see the colors you are going to have to find someone willing to take theirs apart and get them for you. Make sure that resistor is all thats bad on the whole board, seems like if that would burn out something else might have, and soemthing else might have in one of the chips. You just never know.