I have been noticing ever since buying my car that the engine starts and runs just fine in the morning or on cold start-ups, but it struggles and almost dies when the engine is warm and I try to restart. If I am running errands or something each subsequent start-up the engine seems to struggle at first and then idles fine. The other day though it did as it usually did with warm start, but struggled a few times as I began driving and then idled normally.

I live in the sf bay area so temp is pretty moderate and the temps here havent been fluctuating or anything out of the ordinary, so I don't understand what ECU could be doing. Anyone ever experience this or have any clue what could be causing it? Thanks in advance.

 

i think i have a similar problem.

in my case the following happens:
1 (cold start) , high idle which comes down normally.
2 (warm start), quick startup, but revs drop to below warm idle, and then get back onto regular idle almost immediately. struggles for a second at most.

im assuming its nothing serious, probably something to do with the idle air, or mildy clogged injectors, or air temp problem. Most likely due to some part bieng old or dirty.

I hope someone can chime in, and give us some insight into what it is.

 

Apart from that one instance of extended struggling the other day, that is exactly what mine does. I have been using an injector cleaner, so I don't think thats the issue.

 

it may well be, allot of injector cleaners do the opposite of what they say.

the best way to clean injectors is to take them out and have them cleaned ultrasonically.

the reason that some in-tank injector cleaners may not work is because they might free up some gunk before the injectors and therefore cause the injectors to get clogged.

btw i too have use injector cleaner, so it might be the same thing.

 

I am getting a similar problem in my MY03, i get very lumpy running for up to 1 minute if the car has been standing for 10 to 30 minutes after being run up to temperature.

Currently been into dealer 3 times and had new MAP sensor and new coil pack - still not fixed.

Finally got an engine fault code register on Saturday, it is showing the primary o2 sensor high voltage. This should be replaced this week. I will keep you posted if this fixes my problem. Might be something to consider!

See previous link for more info...
search "Rough running on warm startup" on under the hood forum (cant get link to work!!)

 

Never heard of that, but it makes sense. I would assume that continued use of the cleaner would eventually completely breakdown whatever particles were in there...maybe people don't continue use long enough.