Author Topic: rough idle//stalls out at stops (Read 6667 times)

stereomotional · « **on:** December 10, 2008, 01:30:36 PM »

did a motor swap recently, got a donor m42 so i threw it in. the motor was flawless in the car i got it from, but about a week after i swapped it, i noticed a coolant leak. it ended up being a hose on the plastic coolant flange under the intake, so took care of that. after that, now when it runs, it has a horrible idle, and stalls almost everytime i stop. could this possibly be air pockets in the coolant from when it was leaking? i swapped in the icv and air meter on the air box from my old motor which worked fine, and still nothing. i attached a video of the car at idle and heated up fully.

oh, and econo gauge and temp gauge on the cluster go crazy too...trying to familiarize myself with this motor still, so bear with me. uploading a video now, will post as soon as it finishes.

derek9702 · « **Reply #1 on:** December 10, 2008, 01:57:24 PM »

Sounds like a vacum leak

stereomotional · « **Reply #2 on:** December 10, 2008, 03:46:03 PM »

thats what i thought too, but i checked all lines, did a smoke machine test at my work, and even unloaded almost a whole can of brake cleaner on my motor @ idle, and no vac leaks...

stereomotional · « **Reply #3 on:** December 10, 2008, 03:46:37 PM »

and btw, dont worry about the chain slapping in the vid, getting a tensioner next week, for some reason, the camera amplifies the sound, making it WAY louder than it actually is

B318M42W · « **Reply #4 on:** December 10, 2008, 07:52:36 PM »

just throwing it out there... maybe you could try to make a vacuum leak and see how it reacts? if it idles better, then it's beacause not enough air goes in or too much gas.

stereomotional · « **Reply #5 on:** December 11, 2008, 11:39:27 PM »

i got all new intake gaskets laying around, im thinking about changing them all out, but i dont have one for the tbody, the heater plate is deleted so there is no actual gasket to use...so i kinda made one, and im not sure about it. maybe ill use some of that make a gasket stuff, the roll of aluminum

roundel318 · « **Reply #6 on:** December 12, 2008, 08:06:53 AM »

I think the gaskets are the next place to start looking

stereomotional · « **Reply #7 on:** December 15, 2008, 09:21:53 PM »

yeeaaahhhh soooooo the TB gasket i made wasnt any good, pulled my tb off tonight, and inside of my manifold was wet, leading me to believe that the tb gasket was leaking, im going to make a better one out of aluminum gasket material at the toyota dealership i work at, and go from there.

roundel318 · « **Reply #8 on:** December 16, 2008, 11:06:51 AM »

I would think Pelican or someone like that would have something for you for cheap?
Good you are finding the source of the problem

txleadfoot · « **Reply #9 on:** December 16, 2008, 01:21:25 PM »

The aluminum gaskets retail online for $1.56. Don't waste time trying to make one.

tjts1 · « **Reply #10 on:** December 16, 2008, 02:48:17 PM »

Have you eliminated ALL the vacuum and coolant hoses under the intake manifold yet? See my signature.

stereomotional · « **Reply #11 on:** December 16, 2008, 05:41:35 PM »

yeah its been done, actually the motor is out of "oldtimers" e30, i bought it about a month or two ago. im starting to wonder if the vacuum lines are collapsing like you said, cause im 99% sure that there are no vac leaks. slapped everything back together and let it idle for about 45 mins, idle got a bit better but went right back to square one. i noticed thatwhen my electric fan cuts on, the idle smooths out, and it cuts off...idle gets bad again......this is really throwing me off.

roundel318 · « **Reply #12 on:** December 16, 2008, 06:04:03 PM »

Do you have a spare ECU to try out?

stereomotional · « **Reply #13 on:** December 16, 2008, 06:48:09 PM »

na, i dont think its an ecu...dont get me wrong i really appreciate all the input, but i dont really think its an ecu, maybe im wrong.

stereomotional · « **Reply #14 on:** December 16, 2008, 07:16:52 PM »

ok so i checked and checked and check all lines/hoses, anywhere where air/vacuum is, everything was ok, except for the nipple on the bottom of the intake for the icv, so i replaced with one laying around, that wasnt cracked. my idle is still fluctuating and stalling at stops, yes i know, "just like a vacuum leak". like i said before, i noticed that the idle smooths out when the electric fan cuts on, everytime, then when it cuts off, idle goes to shit again. im dumbfounded here, i thought it could have been coolant air pockets, but ive purged it through the radiator vent screw many many times, swapped all my intake gaskets, swapped icv and air meter...nothing.

btw, the arrow on the icv is supposed to point towards the manifold...right? hah