running rough till warmed up

[rdoms6]

it been doing this for awhile now. but getting worse.
it's a 2002 t5 with headers and intake. i have about 85,000mi on it a race autocross
i have to let it warm up for a few minutes before i take off or even rev it up. if i try it will jump and stutter and miss. but if i let it warm up it runs alot better but not perfect. when i try and rev it up it struggles to gain rpm's quickly and miss when it does.

also if i do a high speed run on the highway to where it gets hot it will start running rough.

any ideas on what i should do or what it is?
thanks for the help

[Barbadian Camaro]

Re: running rough till warmed up

When you first start on mornings does the engine idle high and then idles lower shortly after?

[rdoms6]

Re: running rough till warmed up

no it doesnt. it idles pretty normal its just when i give it gas that i notice it running bad

[Atrum Rosa]

Re: running rough till warmed up

When you first start on mornings does the engine idle high and then idles lower shortly after?

Mine does. Is this a bad thing? I always assumed it was the car warming itself up.

[rdoms6]

Re: running rough till warmed up

i think he means abnormaly high. all cars idle a little high when they are first started

[Cool81z28]

Re: running rough till warmed up

Have you checked the spark plugs

[ACiFiC]

Re: running rough till warmed up

Check spark plugs wires and then check your coils

[rdoms6]

Re: running rough till warmed up

also i took it for a ride today and got on it. at full throttle it hesitates and stutters. so it sounds like a spark problem?

[ACiFiC]

Re: running rough till warmed up

it almost positive it is one of the three i listed

[Mogobs30th]

Re: running rough till warmed up

it almost positive it is one of the three i listed

I have a better idea, if its tripping an SES light, check to see what code it is thats popping. Cannot say this enough....SCAN THE PCM. GET CODES. COME BACK HERE. We can go from there.

[ACiFiC]

Re: running rough till warmed up

I have a better idea, if its tripping an SES light, check to see what code it is thats popping. Cannot say this enough....SCAN THE PCM. GET CODES. COME BACK HERE. We can go from there.

I don't think those trip the PCM codes, but I guess everyone would have assumed he would have mentioned it in his problem description..

regardless he has the same symptoms i've experienced with that issue, but we will wait for a reply.

[Red&Black_Attack]

Re: running rough till warmed up

Sounds like it could be the MAF possibly. Mine did this too... Didnt trip the SES light either.

Try unplugging the maf and see if it changes anything, if it does then there's your problem.

If not, do what ACIFIC told you.

[rdoms6]

Re: running rough till warmed up

i just scanned it and it threw 6 codes. they are all o2 sensor related. p0131, p0135, p0137, p0140, p0151, p0155. does this help?

i should note that i do not have a cat on it so there is a o2 sim in the one after the cat, which i don't think works

[rdoms6]

Re: running rough till warmed up

this may help. see how it stutters at 2grand. im not feathering the throttle just pressing it to about 3/4 throttle. right around 23sec mark it really does it.
http://www.youtube.com/watch?v=mhUMjv3cAnE

[Mogobs30th]

Re: running rough till warmed up

I don't think those trip the PCM codes, but I guess everyone would have assumed he would have mentioned it in his problem description..

regardless he has the same symptoms i've experienced with that issue, but we will wait for a reply.

1. Codes can pop without the SES light being tripped.

2. There are no codes that will pop for plugs or wires in themselves, but there are probably over 100 codes that can pop due to misfires, stutters, and stalls. And again, some of them might not trip the SES light. Pulling plugs and wires is a decent start, but doing that and NOT checking the PCM is halfassed, and throwing parts at a problem is costly and counterproductive in many instances.

3. I've seen too many threads on several sites about a problem and it taking 3 pages for the OP to finally come out with a piece of info that many ASSUMED didn't happen. Assumptions are like *******s, they smell and are worthless. Get all the info possible.

And 4. After over a decade, two 3800 Series II fbodies, I might actually know what **** I'm talking about.....surprisingly, my idea is FREE at some auto parts stores.

Please, do a diagnosis the right way and get the car scanned before you do anything else