HOT ENGINE STARTING PROBLEM
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HOT ENGINE STARTING PROBLEM
Hello !
sometimes when i'm starting the engine again after few minutes since i turned it off and it is hot ,it takes 5-6 starter turnes to turn it on when usually it will start by one touch!
but that's not all ... after it starts it begines to rev till it gets to about 2000 RPM
and then goes down to 1000 RPM ... I start driving and then it again revs up and down like it has a mind of his own . the problem dissapears by itself after 1-2 minutes and the engine balances at 700 RPM as it should.
it never happens on first morning start or after several houers car rests since driving.
I HAVE A 2000 180 HP FWD TT COUPE ,the only mode's i did are: forge splitter ,Awe boost guage and a K&N air filter .
need help with solving this prob., dont have a VAG COM ,like DIY ,hate AUDI dealers....
thanx, Avi .
sometimes when i'm starting the engine again after few minutes since i turned it off and it is hot ,it takes 5-6 starter turnes to turn it on when usually it will start by one touch!
but that's not all ... after it starts it begines to rev till it gets to about 2000 RPM
and then goes down to 1000 RPM ... I start driving and then it again revs up and down like it has a mind of his own . the problem dissapears by itself after 1-2 minutes and the engine balances at 700 RPM as it should.
it never happens on first morning start or after several houers car rests since driving.
I HAVE A 2000 180 HP FWD TT COUPE ,the only mode's i did are: forge splitter ,Awe boost guage and a K&N air filter .
need help with solving this prob., dont have a VAG COM ,like DIY ,hate AUDI dealers....
thanx, Avi .
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Joined: Jun 2000
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pollution control valve.....>>>
on all modern day cars....if they fail, there are some instances where it can impact a hot start. if your car has any mileage on it, like more than 80k...you are probably a candidate for replacement...
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or another vacuum leak causing an initial lean condition>>
until the computer detects the lean burn and injects more fuel. on a cold start the computer injects more fuel initially anyway, to get the car running. on a hot start it does not, so thus the challenge.
on older Audis (and other Bosch CIS cars) they had an extra (5th or 6th depending on 4/5 cyl) injector called the "cold start injector" and it was in the intake manifold. when the computer detected the coolant was cold, it would spray fuel thru this injector to help the engine start. on modern cars this functionality is handled at each cylinder via the electronic fuel injectors, so no need for an "extra."
i would look at PCV like Hans says, and also at the plumbing to your boost gauge... and also, at all vacuum lines attached to the manifold.... our cars are about the same age, and I just had to replace a couple vacuum lines that had failed due to age.
on older Audis (and other Bosch CIS cars) they had an extra (5th or 6th depending on 4/5 cyl) injector called the "cold start injector" and it was in the intake manifold. when the computer detected the coolant was cold, it would spray fuel thru this injector to help the engine start. on modern cars this functionality is handled at each cylinder via the electronic fuel injectors, so no need for an "extra."
i would look at PCV like Hans says, and also at the plumbing to your boost gauge... and also, at all vacuum lines attached to the manifold.... our cars are about the same age, and I just had to replace a couple vacuum lines that had failed due to age.
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yep...got that cold starting injector on the 911>>>
which looks to be in MEH condition or needs to be cleaned.....
Need to replace a bad fuel line right now that decided announce how shot it was yesterday...weeping gas right through the braid....no big deal, just in an interesting location...Typical of Porsche!! ;-)
Morning Chris!
Need to replace a bad fuel line right now that decided announce how shot it was yesterday...weeping gas right through the braid....no big deal, just in an interesting location...Typical of Porsche!! ;-)
Morning Chris!
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Re: or another vacuum leak causing an initial lean condition>>
thank you , i'l be checking all vacum lines ,tough it is strange as it doesn't happen all times , so i expect a broken vacum line will make an all-time problem...... any way i'l let you know .
Avi.
Avi.
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it is an "all-time" problem, but the computer compensates based on feedback from the>>
O2 sensor. However, before the car is running, there is no feedback from the O2 sensor, so it's running "closed loop." It has some adaptation capabilities but not sure what if any effect they have on startup.
I would start with vacuum lines, but it could be a lot of things.
Is your Check Engine Light on? If so, start there, reading the codes.
I would start with vacuum lines, but it could be a lot of things.
Is your Check Engine Light on? If so, start there, reading the codes.
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