MAF problem, please help quick...!!

J

jpaitala

Guest
I had my Head caskets just done, but now as I start my SC it idles like crap. If I unplug the maf harness the idle will come back to normal, but at the same time Check Engine Light will come on.

Does anyone know what's the problem??

Thanks.
 
How bad did your head gaskets go? If it really blew water out of them and through your exhaust it could be your cats are clogged, maybe just enough to cause temp problems. But what happens when you unplug MAF it goes into a closed loop mode or basically a survival mode so it does what it has to to run. Any other symptoms other than bad idle?
 
No other symptoms... The caskets weren't at bad condition and I didn't lost much engine coolant before the "casket job".
The repair was done immediately when the first white smoke occurred.
 
Well If I were you I would run it with MAF connected for a few miles to clear out anything in exhaust. While you do this check boost and see if it is at normal levels. If those are good then disconnect battery for 15 minutes and try again, if problem still persists then comeon back and we can brainstorm a little more. Just pay close attention to any differences from before.
 
Thanks. I will drive the bird enough to clear the exhaust today after I get out from work. The only difference that I discovered besides the idle being crappy was that I had not as much vacuum during the idle as I used to have. Before the casket job the vacuum was reading ~16-17 and now ~13.
Can this affect the idle quality somehow??
 
Sounds like you may have some vac leaks. Check to make sure all the IC tube connections are sealed up good.
 
All IC connections are sealed up good... as far as I can check them.
 
I agree with vacuum leak, definately will cause idle probs. Time to get some carb cleaner and start car and spray all vacuum fittings, if idle drops you found a leak.
 
Can vacuum leak cause the problem I wrote about in the first post??
 
If I disconnect the MAF then the idle will come to normal.
But once the MAF is reconnected the idle will go into "real bad" mode.
 
That is because with the MAF connected, the computer is being told exactly how much air is entering the engine. If you have a vaccum leak the engine computer will have the incorrect information since you are either losing boost, or losing intake air.

The engine will fight with itself between proper mixture, and maintaining idle, tweaking this to get proper mixture, then tweaking that to fix idle, then having to tweak that to fix mixture... and on and on causing the flaky idle you see.

Disconnect the MAF and the Engine computer doens't look for a reading. Instead it uses a default value and guesses at the rest, simply using the IAC to maintain idle. Since it doesn't have the MAF to report something different, it assumes all is well.

You've got a vaccum leak somewhere. THere is a FAQ entry for tracking down vaccum leaks.
 
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