cold start idle only?

[E30_(1st Musk)_]

my car has a problem with cold starts. ive already searched. and i am in the process of replacing the fuel pump and going to buy some other gaskets soon...

when starting the car. i have to step in and out of the gas, and i just hear popping sounds coming from the exhaust until it finally gives in....fuel pump possibly?

Also, i changed my throttle gasket because of an idle problem, i kind of fixed that....when the car is driven and a bit worm it runs fine..but when its cold it idles really rough, and even sometimes turns off.

?????

thanks in advance guys

[jlevie]

That sounds like an intake leak or something that affects the cold start mixture. Depending on what car it is there are different possibilites for cold start mixture problems. But before investigating those you should have a smoke test run ton the intake to find all of the intake leaks (or to prove that there aren't any).

[E30_(1st Musk)_]

what exactly is a smoke teset???? i hear a little his from under the intake manifold. but i cant put my finger on it. i know there are two hoses under there. the one that connects to the throttle i zip tied in place. and the other seemed lose. but idk if it was supposed to be so


and its a 89 325i

[SpecM]

what exactly is a smoke teset???? i hear a little his from under the intake manifold. but i cant put my finger on it. i know there are two hoses under there. the one that connects to the throttle i zip tied in place. and the other seemed lose. but idk if it was supposed to be so


and its a 89 325i

a "smoke machine" will pump an inert and nontoxic steamy-looking gas (smells like lemons, lol) into an intake, and you look and see where it leaks out at, if at all.

what did the "other" hose go to?

[E30_(1st Musk)_]

a "smoke machine" will pump an inert and nontoxic steamy-looking gas (smells like lemons, lol) into an intake, and you look and see where it leaks out at, if at all.

what did the "other" hose go to?

ohh okay! lets see how much that would cost...

and the other hose went up into the intake manifold. somewere directly above the injectors. i couldnt see much because i only took off the throttle to change the gasket

[Fcknslo]

sorry to thread jack but I kind of have the same problem except that when my car starts it dies like 2 seconds after and feathering the gas doesn't do anything. would that still be considered a vacuum leak?

[E30_(1st Musk)_]

okay. i changed the fuel pump....but when i start the car for the first time of the day. i hear alot of backfire from the engine bay until the car finally starts...any idea guys?

[DMF]

I know this is a 5 month old thread... but I was wondering if you guys had any updates on this issue? 325is has had this same issue for the past week or so.. I have to give it a lot of gas, forcing it to rev through the back/misfiring.. after a bout a minute or so things smooth out and the motor will run fine. Lately it's been getting worse where the motor will die a couple times before I can get it running fine. This is only when I start the car after it has sat for 6+ hrs..

[jlevie]

The most common cause of cold starting problems are intake leaks. The best way to find them is to have a smoke test run. While there can be other contribtors, there's no point in considering those until it is known that there are no intake leaks.

[DMF]

Yeah, that seems to be the first step to diagnosing the issue.

Can I rent a smoke machine to do the test? or whip up some home made device?

[Kev]

Orr could be that Fuel tempature sensor that has failed on you.. i think thats what its called mine failed on my black one. had the same problems