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View Full Version : Rough running engine..


Yakker
03-05-2007, 05:17 PM
Ok, i just finished with replacing my head gasket and started it up after filling coolant and now its running very rough almost like all the cylinders aren't firing. And it won't idle at all, the trottle has to be pressed in order run at all. I just literally just started looking at it and i'm waiting for a friend to come by to have an extra set of hands to look at since it wont run without the throttle pressed. But i thought i'd post on here to see if anyone had any quick suggestions... will get back if i figure it out... oh yeah and its a '90 525i m20
Yakker
03-05-2007, 06:09 PM
Everything seems to be firing ok. Throttle has to constantly be pumped and not held in place in order for it to run. We're currently going back and making sure all the connections that were disconnected are in order. I replaced the vacuum purge valve with one from a salvage yard. And replaced all the gaskets including the throttle body, and also replaced all the stock hose clamps on the vacuum system with adjustable type clamps. The head was replaced with a brand new head. Filled the oil with castrol syntech.
etcetera
03-05-2007, 08:12 PM
Did you hook up the idle control valve?
Blitzkrieg Bob
03-05-2007, 08:32 PM
Vacuum hoses, clamps, & the temp sensors on the water neck
Yakker
03-06-2007, 04:14 AM
Yep, check, check, check, and check... i think i made a post too early but i'll keep ya'll up to date... I'm gonna go ahead and go back through the intake and vacuum and pretty much start over again and hopefully find it. hoping its not an injector issue.
Yakker
03-23-2007, 10:48 AM
Well I haven't really had time to look at things till recently, i've changed all the hose clamps to new adjustable type clamps. But i've started to suspect the idle control valve. It will actually idle with the valve unplugged. I took the valve off and sprayed some carb cleaner in it, shook it around, and emptied it. Tried running it again with no luck, but it actually seemed like it was trying to idle for a second the couple times it died. Any thoughts?
winfred
03-23-2007, 11:42 AM
make sure the vent tube that goes from the block to the bottom of the intake manifold is all of the way into it's hole, that will make a pretty nasty vacuum leak, another thing that can come up after a head job is leaving the front engine lifting bracket off, this puts the distributor cap out of position, seen it a few times
winfred
03-23-2007, 11:42 AM
or the valves are adjusted too tight