Engine stutters when cold
08-05-2009, 04:42 PM
#1
Team Owner
Thread Starter
Engine stutters when cold
My car is a '99 C4 with a reman engine...53k miles on the car with 10k miles on the new (to me) engine. For months now it's been stuttering when I hit the gas after a cold start. It seems to idle just fine, but as soon as I get it out on the street it stutters and bogs down when I hit the gas pedal very hard at all. It usually does this for a minute or two and then operates perfectly normal.
Any ideas? TIA!
Any ideas? TIA!
08-05-2009, 05:03 PM
#2
Race Car
Hey Jake, you aren't stomping the throttle when it's cold, are you? 
Check around the throttle body and intake runners for any lines that may have cracked.
Sounds like you are facing a small vacuum leak that is null once the engine is a little warmer.
Check around the throttle body and intake runners for any lines that may have cracked.
Sounds like you are facing a small vacuum leak that is null once the engine is a little warmer.
08-05-2009, 08:01 PM
#3
The Penguin King
Rennlist Member
Rennlist Member
Try running a bottle of Techron through it. I've had pretty good luck with the product both in my 997 and my 996. I was very skeptical, but it seems to me that it helps quite a bit. Of course it could be something else entirely with your car, but Techron is a cheap fix if it works.
08-06-2009, 02:13 PM
#5
Team Owner
Thread Starter
Try running a bottle of Techron through it. I've had pretty good luck with the product both in my 997 and my 996. I was very skeptical, but it seems to me that it helps quite a bit. Of course it could be something else entirely with your car, but Techron is a cheap fix if it works.
I guess I assumed that it couldn't be that because it works itself out so easily and I've never seen any kind of smoke from the rear...do you think it's still a possibility?
08-06-2009, 03:14 PM
#6
Rennlist Member
I have this same exact problem. What works for me is "priming" the fuel pump, turning the key to "on" but not "start" and letting it sit while I buckle in and whatnot. Then when I start the car the stuttering issue is mostly gone.
I figure I'm losing fuel pressure while cold, not really an issue and I basically forgot about it since it just became habit to do the key trick so I forgot about it. Really should check into it though.
I figure I'm losing fuel pressure while cold, not really an issue and I basically forgot about it since it just became habit to do the key trick so I forgot about it. Really should check into it though.
08-06-2009, 03:52 PM
#7
Team Owner
Thread Starter
I have this same exact problem. What works for me is "priming" the fuel pump, turning the key to "on" but not "start" and letting it sit while I buckle in and whatnot. Then when I start the car the stuttering issue is mostly gone.
I figure I'm losing fuel pressure while cold, not really an issue and I basically forgot about it since it just became habit to do the key trick so I forgot about it. Really should check into it though.
I figure I'm losing fuel pressure while cold, not really an issue and I basically forgot about it since it just became habit to do the key trick so I forgot about it. Really should check into it though.
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08-06-2009, 06:57 PM
#8
Rennlist Member
I had no smoke except a puff on startup. On cold starts (the colder the day the worse it was) the engine would stutter and sometimes stall. Frequently the engined revved high on start and then ran rough until it warmed up. After a new AOS all was well. It can be easily checked by someone with the right tool.
01-18-2011, 03:25 PM
#9
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Old post, but did enyone find a solution for this?
My car seems to have same symptoms, starts fine and idles well. Drives good if you don't push too much gas. Symptoms go away when the temp reading are roughly 50deg Celsius.
It souds like it's running lean, so I think it's the temp sensor or maf.
My temp meter works, but is there different sensor for ecu?
Allso, whats the sensor in intakemanifold?
My car seems to have same symptoms, starts fine and idles well. Drives good if you don't push too much gas. Symptoms go away when the temp reading are roughly 50deg Celsius.
It souds like it's running lean, so I think it's the temp sensor or maf.
My temp meter works, but is there different sensor for ecu?
Allso, whats the sensor in intakemanifold?
01-20-2011, 08:39 AM
#10
Three Wheelin'
Old post, but did enyone find a solution for this?
My car seems to have same symptoms, starts fine and idles well. Drives good if you don't push too much gas. Symptoms go away when the temp reading are roughly 50deg Celsius.
It souds like it's running lean, so I think it's the temp sensor or maf.
My temp meter works, but is there different sensor for ecu?
Allso, whats the sensor in intakemanifold?
My car seems to have same symptoms, starts fine and idles well. Drives good if you don't push too much gas. Symptoms go away when the temp reading are roughly 50deg Celsius.
It souds like it's running lean, so I think it's the temp sensor or maf.
My temp meter works, but is there different sensor for ecu?
Allso, whats the sensor in intakemanifold?
I always let mine run for two minutes till the idle drops then I go seems to prevent this hesitation people talked about.
01-20-2011, 09:56 AM
#11
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No, not the maf.
It's in the right intakemanifold, between intakerunners. Top of the plastic intakemanifold, right about where the ac-pump ends.
Just ordered the Durametric so I can check all the sensors.
If all the sensors are ok, I think that the intake leak is the problem.
It's in the right intakemanifold, between intakerunners. Top of the plastic intakemanifold, right about where the ac-pump ends.
Just ordered the Durametric so I can check all the sensors.
If all the sensors are ok, I think that the intake leak is the problem.
