Member
okay so today i took the whole manifold off my 1998 m3 and replaced the oil separator vacuum lines cleaned the idle control valve with starting fluid, cleaned maf with contact spray replaced intake boot and practically every hose. I went to start it up and it starts and it revs around 2000 rpms for like 4 seconds then in tries to idle but idles very very rough and then stalls. What could be the problem?? What would cause it to rev high on startup then stall out? Vacuum leak? Any ideas would be great thank you.
The Anomaly
If it worked fine before you took the manifold off it Has to be a vacuum leak, a very large one at that, have fun going through everything again
Member
What would case that big a vacuum leak? I'll give it a check.... Don't feel like doin all tht shit again lolOriginally Posted by UnderCoverGuy11
Member
Usually intake boots crack, you sure you didn't mess up maf when u cleaned it
95 BMW M3 Alpine-
<GO...JIC Cross Coilovers- UUC RCAB, AKG FCAB, Rogue Engineering TM bushings- AA Gen3 Exhaust- Dinan F&R Strut Bars- Dinan F&R Sway Bars- X-Brace- Mishimoto Rad- BBS RK 17x8"- TRM Chip- Dinan BBTB- DIY CAI- JP Performance Headers- 21.5 injectors- JB Racing Flywheel- Bimmerworld TB boot- 540i MAF><SHOW...OE euro clear exterior lights- Depo w/ HID- Hurricane Alcantara interior- Stereo (Kenwood,Sony,MB Quart,Rockford Fosgate,JL Audio)- Black kidneys- Euro 3 Spoke- ZHP Knob- AutoDim Mirror>
Member
yeah mine was but i replaced it and i unplugged it but it didn't seem to help so idt so. The car runs really strong otherwise
The Anomaly
Check the ICV connection under the boot, it might have worked it's way loose
Member
it was a crack in one of the hoses. Its all sorted out nowThanks
Member
Well it wasn't that hose. Replaced it and it still dosent wanna idle and running really rough. Also starting to backfire and miss. I'm stumped there's no way a little vacuum leak can cause all this.
Last edited by BMW325issport; 08-15-2013 at 12:21 PM.
Member
Is the brake booster hose connected properly?
Member
BMW CCA Member
did you screw up the MAF? Try unplugging it and running. If it idles better than the MAF needs to be cleaned/replaced.
oh, you already did this....
...then it makes no sense to me. Car would be running on a baseline tune w/o an air measurement. That would mean a fuel issue I think. Or the throttle plate is so tightly closed it's not getting any air in.
Last edited by Moron95M3; 08-15-2013 at 12:38 PM.
Member
ill check the brake booster but its pretty tight. Do you guys know what that plastic vacuum hose goes to? Its currently unplugged from the manni. Would the idle control valve cause all this? I did clean it and idk if i broke it. I used starting fluid to clean it.
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