stumble when i first take off??

[ptownTSI]

When I first pull out of my parking spot for the day sometimes my car will fall on its face for a few seconds then recover and it will never have the problem for the entire rest of the day.

usually it only happens if the car sits for oh say at least 24-30hours.

any idea's?

[tjmonsen5]

my car has the same problem! but it also stumbles throughout the entire rpm range, and it is really annoying! my car always runs like this, doesnt matter how long it sits for. So far this winter i have replace:
Injector seals, rubber intake boot, air filter, fuel filter, fuel lines, cleaned afm and throttle body, vacuum lines. It improved a little bit, but it is still stumbles all the time. I heard someone say it could be a clogged catalytic converter?

[ptownTSI]

it just stumbles for a couple seconds, put it in first take off get to about 2krpm's and then they fall to about 1000 as the car hiccups, then picks back up and no more problems.

[PiercedE30]

maybe a something simple like a clogged fuel filter or something.....

[tjmonsen5]

no its not a fuel filter because i replaced mine and it still stumbles. I think it is a clogged cat or has something to do with electrical like spark plugs, wires, coil and cap.

[trent]

Afm

[winstontj]

I am experiencing this problem as well. Our cars need a vacuum in the intake (negative atmospheric pressure) to run properly. Try taking the oil cap off the valve cover with the car started and see what happens.

What happens to you is when the throttle plate opens it lets in enough air to equalize the pressure before and after the intake essentially shutting down the motor. The ECU takes a second to catch up and dump more fuel in... then it runs again. Sound right?

I plan on looking at ignition and overall tune (always a good place to start but probably not the cause in this instance) next moving over to the vacuum system which IS probably the cause. Check your ICV and all your vacuum fittings/hoses. Finally move to your TB and check the idle. Where is your idle at normally? If this is through the entire RPM range it could also be your AFM as trent mentioned.

[Silence*]

Acording to Haynes Repair manual, these can cause stumbling:

1) Spark plugs fouled
2) Fuel ingection system malfunctioning
3) Fuel filter is clogged
4) Incorrect ignition timing
5) Intake manifold air leak

[dvs909]

i had this happen to me, i put iso dry in the tank and it stopped.
my cars wierd
________
Yamaha yz85

[Jamil]

Let us know if you fix it. I have the exact same problem. Very annoying. My car had a full tune up, cleaned the ICV and TB. Checked the intake tube. New fuel filter. etc. etc.... Still love it though ;)