Ok so I just finished my 4th plenum pull ever, and after putting it back together, I started it up and all seemed well, until I put it into drive to drive it out of the garage, and the revs dropped down to about 400 then went back up, and the car started softly rumbling/vibrating (not the sort of rumble that I had with it missing a few months back, it was a lot softer.) I instantly turned it off and opened the bonnet, and there is a really fuel-y smell in the bay, but I checked everything again to do with the fuel system to make sure all the clamps were tight, etc. I'm not sure what I have done, seeing as I didn't actually do any major work to it, I just had to replace a leaking coolant line and I also did the air filters whilst working on it. I also checked the PCV lines and intake hoses to make sure there wasn't a loose connection on there. I know it's a shot in the dark and it really isn't much to go off, but can anyone provide ideas as to what the problem could be? All I know is that I'm catching the bus to a job interview tomorrow morning and hoping like hell that I'm not late.
Its common to connect the windscreen water wiper hose fitting into the vacuum mix because its the same length/ line - this can cause your problems, of low idle/ vibration and assuming the water worked in when going to drive. Sounds silly to suggest this but given its so easy and it happens a lot, I will suggest you check the wiper hose line first to make sure it hasn't replaced a vacuum hose when restoring the hose lines after the pull Also - if no luck - try this Are the fuel lines around the right way? Check the fuel rubber hose section that connects both the rails, to make sure its not loose. A lower plenum injector O ring seal can cause the above (assuming the vibration from putting into drive started the leak) Just guessing, you need to run through a step by step check starting with the fuel pressure (test the spark on each cylinder as well) - you will know a lot more by then! Cheers JC
Likely that you're running lean due to a vacuum leak. Could be plenum gasket or you could have also have knocked an injector pulling the plenum off and damaged old injector insulators, or damaged the IAVC solenoid removing the plenum. Easy to create a vacuum leak when you have 25 year old bits hanging around. Pressurise the plenum, search on "boost leak test" or "vacuum leak test", and find the leak.
Buying another gasket was my next plan of attack just to make sure I didn't do something wrong that far down. I checked it again last night and there seems to be a hissing noise coming from near the left intake pipe, so that will be the first place I check when I get the new gasket.
After some more googling around I found that it seems like it's a problem with my IACV as the old owner broke the plug and just crimped on two little connectors for the wire instead. He also did the same for the throttle body connector. Yes he was dodgy as hell.
I'm gonna give the IACV a test and if that is ok then I'll buy the gasket. $20 is a reasonable enough price for the peace of mind.
