Help! check engine light alwasy come up in cold
 

dear all,
I just bought a 93 tt supra which has a very weird problem.

Every time I want start the car in a cold morning, the check engine light will come up, the max RPM I can only rev up to 2000rpm then it will go straight down to idle even I am holding the accelerate pedal, felt like car couldn't suck in any air, also petrol smell will become very stronge,
the radiator fan will work even the car was just started.

At first I was trying to ignore it, but car has no power at all, and it does unbelievable shake if I drive it.

however, if the sun comes out, these will all go away.
I have took it to a garage to get a diagnostic code, but they told me car is all good, has no problem, This almost drives me crazy.

can somebody tell me what wrong is it?
I am very appreciated.

1) The garage you took it to sucks. If the check-engine linght comes on, there will be a code stored in your ecu.
2) What you've described seems to be a tough problem to diagnose. Perhaps a sticking idle-air control valve?

I'd suggest starting by reading your own codes:
http://www.mkiv.com/techarticles/eng...bd1_codes.html
http://www.mkiv.com/techarticles/eng...bd2_codes.html

I'd suggest you should also check for boost/vacuum leaks by pressurizing your charge-air system.

Tnak you, I will try to diganostic by my self.

another problem is, I started the car at afternoon, everything are nonrmal, no engine light, boost and rev are fine...this is completey doesn't make sense:confused:

does the car like to stay under sunshine????

Until we find out your codes, it's all guesswork. It's possible that in cold weather, your IAC valve could be sticking. It's also possible that the IAC has nothing to do with the problem. See what I mean?

Please post the codes when you find them out.

finally found the problem, it was caused by the cam sensor.

now the car was fixed, great day:bouncy:.
thanks for all the help.

Congratulations.

Just curious - weren't codes 12 and/or 13 stored in your ecu?

it was code 13

Did you fix it yourself? Also, did you (or the mechanic) determine why the cam sensors were failing when it was cold?

I tool it to mechanic, cause I couldn't find any diagnosis tool around.

they didn't tell me when you found the code, but I guess the code which they found should be stored in ECU. casue They did they in the morning, and it's not cold.

but I srtill don't understand, what relation between cam sensor and cold weather....

"Diagnosis tool"??? What on earth are you talking about? Where did you get the idea that you had to obtain a "diagnosis tool"?

All you need is a paper clip to "Connect terminal between TE1 and E1 of data link connector 1 or 2". Didn't you read the link I posted???
http://www.mkiv.com/techarticles/eng...bd1_codes.html
That tech article does NOT mention a "diagnosis tool", in any way, shape or form.
:squint:

If you don't mind me saying so, if you'd have fixed this yourself instead of taking it to a mechanic, you would have learned "relation between cam sensor and cold weather".