WTF!?!?! dies when i let off gass and hit brakes...

[bloodshot-e30]

okay ive checked everything no vac leaks or anything but when i let off the gas and hit the brakes it dies.... not all the time its just a random thing!

any ideas?!

[I*Do*Werke]

noob

[Sagaris]

Sounds like a real strange problem. If you can reproduce the problem easily by hitting the brakes with the car in neutral then I suggest removing the vac. line from the brake booster and capping the end that goes to the engine off, air tight. and see if it stops happening. If so, the brake booster is causing a big enough vac. leak to stall the engine. This is not something I have ever heard of, but it seems possible and easy enough to check. If you try this then just remember that your brakes will be very hard to press without the booster connected. Just an idea.

If it was an M20 I would say to check the idle switch but this is in the 24v swap forum so that doesn't apply .

[greyis89]

Haha guess I'm still a newb too. If it's something easy please share. It happens so random even if I try to make it happen it doesn't always stall out. I have some annoying sputtering in shifts and touchy throttle at speed too, so I'm thinkin vac leak, but I haven't done a smoke test or gotten too deep in trouble shooting since I've been very busy after the swap.

[samiam3356]

got the 02 sensor hooked up? once it warms up the dme starts taking that into consederation. I know you just got it together so wasn't sure if you got the exhaust all buttoned up or not.

Mine has a similar issue but waiting until the exhaust is done before I start tearing everything apart again.

[bloodshot-e30]

Sounds like a real strange problem. If you can reproduce the problem easily by hitting the brakes with the car in neutral then I suggest removing the vac. line from the brake booster and capping the end that goes to the engine off, air tight. and see if it stops happening. If so, the brake booster is causing a big enough vac. leak to stall the engine. This is not something I have ever heard of, but it seems possible and easy enough to check. If you try this then just remember that your brakes will be very hard to press without the booster connected. Just an idea.

If it was an M20 I would say to check the idle switch but this is in the 24v swap forum so that doesn't apply .

hmmm ill see if that helps but with my booster if i unplug the vac i have NO brakes... its not a stock BMW booster lol

Haha guess I'm still a newb too. If it's something easy please share. It happens so random even if I try to make it happen it doesn't always stall out. I have some annoying sputtering in shifts and touchy throttle at speed too, so I'm thinkin vac leak, but I haven't done a smoke test or gotten too deep in trouble shooting since I've been very busy after the swap.

i cant get it to repeat either its just completely random. and i have that touchy throttle in 1st real bad i just thought it was cuz of the 4.10

got the 02 sensor hooked up? once it warms up the dme starts taking that into consederation. I know you just got it together so wasn't sure if you got the exhaust all buttoned up or not.

Mine has a similar issue but waiting until the exhaust is done before I start tearing everything apart again.

yes my O2 is on but i just have the exhaust dumped out the side to test everythin out.
also mine WILL not get up in temp unless im sitting at idle with the fan OFF idk why this is either the ther t-stat is new.
also have no heat (im thinking i have the heater core lines backwards and it wont bleed) BUT i gotta figure out this stalling thing. maybe it is because its not warming up all the way... but i gotta say it feels SOOOOOO GOOOD to be 24v again :D

[greyis89]

My throttle is touchy in all gears. It will sputter like a misfire in shifts until I overcome it. It's like you're on the gas or not at all, no happy smooth medium. I'm 3.73. Haven't had it stall when cold. O2 is in and I'm running a basically stock exaust.

[jrdeamicis]

Do you have a check valve in the brake booster?

[bloodshot-e30]

yea but i figured out what it is! thanx guys!

[Blackangusinc]

Could you post your resolution?

[greyis89]

Smoked my car today and found a vac leak at the booster vac line. Waiting for sealer to dry overnight. Otherwise no other leAks elsewhere. Hoping for the best. Was it something else besides a vac leak???

[bloodshot-e30]

i dont have the vac hooked up to whats supposed to be the oil air seperator thats the only thing left that it could be... but now i seem to have a big ticking problem :(

[Mr.SWISS]

If you go at the E21 booster like a monkey fuckin a football you will tear the inner bladder twisting it around. Made that mistake in '05 on swap car #1.

[bloodshot-e30]

If you go at the E21 booster like a monkey fuckin a football you will tear the inner bladder twisting it around. Made that mistake in '05 on swap car #1.

huh?

[Mr Two]

I had this problem before. Turned out to be a vacuum leak - I think it turned out to be the ICV tube was loosely connected to the intake elbow and was causing a small vac leak. Hasn't happened since.