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View Full Version : Problem at take off from a cold start...



hyoctane
01-09-2009, 01:18 AM
So this has been plaguing me for a few months now. I'm having an issue when I take off after a cold start.

Here's the typical scenario:

I get out of work at 5:30 and hop in my car. Key start and everything is perfect, I let it idle for 15-30 seconds and proceed to back out of the parking pace. I place her in 1st gear and attempt to accelerate as I normally would, only it will either: a) act as if I haven't pressed the gas pedal, I could even floor the gas and the car will still be at 1,500 RPM or b) begin to bog and buck. It's strange... It goes away after she warms up, but this occurs every day. The only way to get her going is to feather the clutch and wait for the engine to notice that I have the pedal floored.

I have an '01 GT-S 6-speed w/ an AEM CAI, TRD cat back modifications (the only ones that would affect the "go")

Any ideas?

vip09
01-09-2009, 01:30 AM
Dirty MAF, bad O2 sensor, or something in the EVAP system would be my first guesses. You're not throwing any CELs?

hyoctane
01-09-2009, 01:45 AM
Dirty MAF, bad O2 sensor, or something in the EVAP system would be my first guesses. You're not throwing any CELs?

Nope, haven't seen a CEL light but once on my car 80k miles ago...

I'm planning on cleaning my MAF tomorrow and then removing the negative battery connection to reset the ECU. From there I can narrow it down.

Even more strange is when the car is warmed up and I turn it off, let it sit for a few minutes (long enough to run into a store) and then start her up and take off shes a-ok. This leads me to believe it's not the MAF...

Ryan
01-09-2009, 02:03 AM
Have you checked the spark plugs recently?

Although, I would think that if it runs ok after it warms up that it might not be the plugs, but its something cheap and easy to do..

hyoctane
01-09-2009, 02:08 AM
^^ I replaced the plugs 20k miles ago with some Denso Iridium's... It's not those.

Maybe my distributor? :hehe: j/k

Luni
01-09-2009, 02:17 AM
Dirty maf or something in the O2 sensor is my guess sir.

Ryan
01-09-2009, 02:36 AM
^^ I replaced the plugs 20k miles ago with some Denso Iridium's... It's not those.

Maybe my distributor? :hehe: j/k


LAWL... Where???


coil over plug pwnts joo..

JK

kungFUBAR
01-09-2009, 02:53 AM
Nope, haven't seen a CEL light but once on my car 80k miles ago...

I'm planning on cleaning my MAF tomorrow and then removing the negative battery connection to reset the ECU. From there I can narrow it down.

Even more strange is when the car is warmed up and I turn it off, let it sit for a few minutes (long enough to run into a store) and then start her up and take off shes a-ok. This leads me to believe it's not the MAF...

When you disconnect the battery, turn your headlight switch on while it's disconnected. That insures that all the power is drained from the system.

vip09
01-09-2009, 07:42 AM
Now that I think about it, my car was doing this before I replaced my O2 sensors.

The heater circuit in one of the sensors could be bad.

donteatbugs
01-09-2009, 08:33 AM
broken lift bolts?

CriScO
01-09-2009, 10:09 AM
If it weren't for the problem going away at warm up, I'd say TPS. But since it does I'd go with the MAF, too.

CriScO
01-09-2009, 10:11 AM
broken lift bolts?
Maybe. Does it run 14.7 or 17.7? That's how you tell. Can't run 14.7's without LIFT! :hehe:

hyoctane
01-09-2009, 01:37 PM
broken lift bolts?

Not those, I had the revised lift bolts installed a couple of years ago...


Thanks for the reply guys -- I got more replies here than over at another "new celica" forum... hmm.

I'll look into the 02 sensors, only, which one would be the culprit? pre or post cat 02 sensor? I hope not both...

ciento44
01-09-2009, 03:32 PM
Does your CEL work?

hyoctane
01-09-2009, 03:47 PM
Does your CEL work?


:eek: Maybe it doesn't? I'll have my OBDII read at AutoZone tonight just to make sure.

ciento44
01-09-2009, 03:52 PM
Because... if the car is fucking up because of something electrical... or a sensor, it should throw a code.

And it SHOULD trip the CEL. So i'd make SURE your CEL works.

vip09
01-10-2009, 07:21 PM
Yeah, my CEL stays on 24/7. It works real good. :)

Scoobydaz
01-13-2009, 09:10 PM
Disconnecting the battery shouldnt reset the fault light. If not the MAP coluld be ur water temp sensor.

Luni
01-14-2009, 02:04 AM
When I pulled a CEL for my MAF in my 7th gen, disconnecting the battery didnt fix it. I had to clear the code with an OBD2 scanner.

92VertGT
01-14-2009, 02:26 AM
Cold to you Floridians and cold are completely different things.







:D

CriScO
01-14-2009, 05:29 AM
When I pulled a CEL for my MAF in my 7th gen, disconnecting the battery didnt fix it. I had to clear the code with an OBD2 scanner.
Luni's right, OBDII has memory. The code will stay unless deleted.