My car decides when it wants to start

[carfanatic89]

I have a 1987 supra NA with a manual trans. Ok well about a month ago my car started acting up, it wounldnt idle and wouldnt start. I found out that oil was on the top of the spark plugs, pulled the intake off replaced the valve cover gaskets and the 4 plugs in the middle of the head i put silicone around them. After working on it, it would only start when it was cold and run fine but if you kill it when its warm and try to start it again it will not you have to wait till it cool again. And now recently it just runs when it wants to. It will start, rev to about 1700 rpms then slowly rev back till it dies. I put in a new coil, spark plugs, and O2 sensor, but with a small budget I dont want to keep throwing parts at hoping it will fix it. Has this kinda thing happened to someone else. Can someone give me a guess on what it is. oh and the exguast smells bad and doesnt smell like gas or burning oil and it doesnt smoke. I also ran a diagnosis and it told me air intake temp. sensor (dont know what that is), netural switch (it turns over but wont start), O2 sensor (just replaced that a month ago) Sorry for the long post.

[west_side_supra]

exhaust smell is from running rich. as for it starting fine when cold but dieing when warm makes me wonder if your injectors are messing up. the IAT "intake air temp sensor" is exactly what it says, it reads air temp to adjust the amount of fuel, the 02 sensor usally doesnt do anything, at least it never did for me. the nuteral switch is just for your clutch pedal, its a little switch that when the pedal is fully depressed that it hits the button so power can continue through the system to allow you to start it. i recommend testing your IAT first, because i have seen many cars run very like crap with this part messed up or missing. as for the location of the IAT i have no clue, thats something someone else could help you out with or look in the TSRM for all the information

[carfanatic89]

well now it changed it will start all the time but now when its warm it you have give it gas right after it starts or it wil die and it misses for about 40 sec the runs smooth without missing at all, doesnt really make sense but im gonna check the sensor and see what i can find

[suprra_girl]

sounds like your afm has bitten the dust
code 31 is a sure sign of that or you have bad wiring from the afm to the ecu

[carfanatic89]

i think its the injectors im going to do a fuel pressure test and go from there. If it is the injectors, on a NA whats the bigest cc injector I can go with out flooding out the motor or changing out or adjusting the ecu

[carfanatic89]

was looking around on the internet an I saw that you could adjust the AFM, and that the OHM resistance of the new injector needs to be the same. so how big could I go if I adjusted the AFM and cept the ohm resistance the same

[carfanatic89]

anyone????

[f00g00]

The IAT is in your AFM, suprra_girl posted previously that it probably bit the dust. Did you try another?
The only adjustment ive heard of for the AFM is the tension adjustment for the flapper so it opens quicker.

[supramacist]

Yes.
You go ahead and adjust your AFM.
I'll keep my 200 bucks.

Lexus 550cc injectors are the largest that I know of anyone using.

If you didn't replace the grommets for the injector to head application.
That 3$ piece of rubber you neglected is going to cost you some work sir.

Work smart. Not hard.
Good Luck.

[zambini]

are you still running stock exhaust? i know the problem seems to be bigger than this, but if the exhaust smells funky, your 20 y/o cats are probably clogged and might be keeping your exhaust gasses from flowing properly.. not saying this is gonna fix everything, but might also be part of the problem.

peace

aaron