b00stn

Hey everyone. I have noticed that every now and then my car will kind of stall when I start it. By this I mean, I push the ignition and the car starts but the idle does not seem high enough to keep the engine running so it kind of bounces between stalling and trying to get going. Sometimes it starts and sometimes it dies. If I time it right, giving a blip on the gas will pull it out of the cycle of stall/run. This happens pretty rarely. The first time I noticed it (this winter), it was very cold outside (well below freezing). It tends to only happen in cold temperatures that I have noticed (but I dont know that if it is something mechanical, it didnt just start this season.) I kind of just assumed that the car did not like the cold too much but then I got kind of worried. Just want to make sure nothing else is going on. I think the battery is good, all fluids are routinely changed, and a fresh air filter was just put in. This also never happens if the car is warm (ie. I drive the gas station, turn it off, then turn it back on and drive home.) Just happens if the car has been sitting at least over night and the temp is cold. Let me know what you guys think

xviper

It's not "random". It is affected by weather. This has been reported many times here, so you are not alone. The ECU can get confused sometimes when environmental conditions change and it doesn't quite know what to do with all the sensor readings.
Assuming you don't have anything actually wrong with your car (eg. bad MAP), just leave it alone. Don't help it by giving it gas during a cold start. Always just push the start button and then let it do its own thing. If it wants to bounce around, let it stabilize on its own. If it stalls, let it. Just fire it up again. It will most likely learn much better and much quicker if you leave it alone. If you help it, you are only making it that much harder for it to learn.
Mine did this every year at the start of winter. It would do it for about 3 to 5 morning starts, then learn and not do it again all winter. Then, in the 4th winter, it never did it at all. Your results may vary.

b00stn

Good to hear. Thanks for the response. I suspected it was related to the cold but just wanted some reassurance. So there is no worry about causing damage to the engine when it is bouncing around like that? Just let it do it's thing?

SenderGreen

If it's the normal sputtering or whatever you call it. Mine used to do it as I would coast to a stop. Usually only in the first 10-15 min of driving before it was truly getting warmed up. I would not try and and keep it from sputtering either. I have also noticed that if the ECU is not reset for a really long time the sputtering becomes almost non-existent. From my own observations, I think the car actually learns how it is warmed up as well. Meaning if it gets used to be being warmed up to 2 bars and one day you decide to split just after the idle drops, it might freak a little when coasting to a stop. I would think this is just caused by engine being a more cold than it's gotten used, but I have seen my car freak when being warmed up more than usual before drive away also (not heat bog happens within first few of driving though). It could a figment of my imagination though. At any rate it seems to clear up over time.

xviper

VERY good point. People who routinely reset their ECUs for whatever reason may tend to have more of these sorts of issues. Our ECUs seem to be very adaptive and learn all the time. Resetting it is like making you forget about last year.

mikey k

Have a read of these two as well, might help!

Wisconsin S2k

both the threads you posted provided more MISinformation than anything. the answer has already been explained very simply, so let's leave it at that. no need to confuse someone who's got the answer, by giving them threads where they have to read through crap and figure out what's actually good info.

mikey k

I dispute they were MISinformation.

Several UK users solved their stalling/idling problems because of them.

B00stn's original problem was similar - I simply gave a couple of other options to consider. Surely that is the point of this forum

I'm sure ther is far more "crap" on other threads.

You may as well close this thread then

Wisconsin S2k

If you're going to give "other options" then make sure they are valid ones.

cleaning the throttle body to "solve" this problem does not actually "solve" this problem. we have gone over the technical aspects of this before. not only does this not really "solve" the problem, it can also be dangerous if not done exactly right.

when you clean the throttle body, you are also inadvertently cleaning the IAC motor. a dirty IAC motor *could* cause this kind of problem. however, simply cleaning the IAC motor will fix it. cleaning the TB unecessary and again, potentially dangerous depending on the method used. telling someoen to clean the IAT motor would be a far more helpful suggestion, than the other suggestion that could potentially hydrolock an engine because of improper technique.

also, this is not a new topic. this is one of the most heavily posted topics on the forum. the best solution is as follows:

first, wait a few days, to determine if it's the ECU getting "confused". this will solve the "problem" the majority of the time.

if after a few days, the problem persists, try the map sensor whack.

if the problem still persists, clean the IAT motor.

if the problem still persists after that, you may need to replace the map sensor.

if the problem still persists, you could have a faulty IAT motor.

by the way, the attitude can be left at the door.

SenderGreen

Another note on the ECU; In the 00-03 helms that I have on page 11-100 there is an "Engine idle learn procedure" that should be performed anytime the ECU is reset (not necessary if you just clear DTC). From memory it is basically letting the car warm up with no accesories turned on until the engine fan kicks in, wait until engine fan shuts off, then begin timing 5 min from this point and do not count any time the engine fan runs. I only threw this out because Xviper told me before that his 00-01 helms dosen't have this procedure, so it may be unknown to some.

EDIT: Now that I think about it I wonder if it even applies to MY 00-01 ECU's. I mean I wonder if it was just not published at first, or if an instruction set was added to the 02-03 ECU's.

EDIT: Anyone running without no.25 backup fuse (pre 06 I guess) and a crappy idle might consider this.