Dan94Z34 Posted November 27, 2003 Report Share Posted November 27, 2003 Hey guys, I have a 94 z34 3.4DOHC auto. When I went out to start the car this morning, everything was fine. Then I noticed that the RPM's were going up and down between 1700 and 500rpms. Then the ses light came on. The car eventally leved out at normal idle, but the light was still on I then put the car in gear and took off. The car drove fine and the ses light went off. The car was still pretty cold when I took of, bearly off the first mark on the temp guage. The thing is I dont have a scan tool, and I can't pull the codes with out one. Quote Link to comment Share on other sites More sharing options...
Dan94Z34 Posted November 27, 2003 Author Report Share Posted November 27, 2003 yeah it has a maf. Quote Link to comment Share on other sites More sharing options...
topless94style Posted November 27, 2003 Report Share Posted November 27, 2003 Hey i had the same problem could be a few different things. Get a can of fuel injector cleaner and spray taht around the intak manifold gaskets. It could be leaking vacuum. Quote Link to comment Share on other sites More sharing options...
Crimson Fury Z Posted November 27, 2003 Report Share Posted November 27, 2003 definatley check fer vacuum leaks, mine used to surge & the SES would be on till i got in and revved it then it went back to normal idle and SES dissapeared. i think it was a vacuum leak, and or bad gaskets Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted November 27, 2003 Report Share Posted November 27, 2003 You should be able to check the codes yourself, since your not OBDII You just have to ground out the ECM by putting a paper clip or something in far right (either upper or lower) two holes on your diagnostic connector and turn the key to the ON position and watch the SES light flash to get your codes. If you search, you'll prolly find a more indepth explanation on here. Quote Link to comment Share on other sites More sharing options...
Redfox340 Posted November 27, 2003 Report Share Posted November 27, 2003 Hey guys, I have a 94 z34 3.4DOHC auto. When I went out to start the car this morning, everything was fine. Then I noticed that the RPM's were going up and down between 1700 and 500rpms. Then the ses light came on. The car eventally leved out at normal idle, but the light was still on I then put the car in gear and took off. The car drove fine and the ses light went off. The car was still pretty cold when I took of, bearly off the first mark on the temp guage. This sounds like an Intake Manifold Gasket from personal experience. Since the engine is recieving non-filter / non-metered air into the combustion chamber (and therefore increasing RPM's) through a cracked intake gasket, the ECM sends out a signal to the Idle Pintle Valve in attempt to lower the idle. Once the Idle Pintle Valve maxs out and the idle hasn't returned to a normal level, the ECM inturprets that and displays a trouble code since the idle will not return to a specific value. However, once idle does return to normal, after the engine has warmed up (since the metal and gaskets have expanded due to heat, causing the leak to self-seal), the ECM will retract the trouble code and the SES light will turn off. I willing to bet that's your issue. To check, spray some carbuator cleaner on the gaskets (with the car running) and if the RPM's fluxuate, you've found the culprit. Best of luck! - Erik Quote Link to comment Share on other sites More sharing options...
SmokesGTP Posted November 27, 2003 Report Share Posted November 27, 2003 94' is hybrid OBD. The paper clip method doesn't work, or at least on mine it does not. It has the same connector as OBDI but the diagnostic port is blocked. Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted November 27, 2003 Report Share Posted November 27, 2003 94' is hybrid OBD. The paper clip method doesn't work, or at least on mine it does not. It has the same connector as OBDI but the diagnostic port is blocked. I couldnt remember when they started the hybrid stuff, I knew it was 94 or 95 Quote Link to comment Share on other sites More sharing options...
Dan94Z34 Posted November 27, 2003 Author Report Share Posted November 27, 2003 OK spraying carb cleaner around the intake gaskes, did not change the idle at all. I need to get a hold of a scan tool and see what the computer thinks is wrong. Quote Link to comment Share on other sites More sharing options...
Bolt_Crank Posted November 27, 2003 Report Share Posted November 27, 2003 my car does that too.... only when it's cold, basically, though, it tells me it's the IAC Quote Link to comment Share on other sites More sharing options...
Bolt_Crank Posted November 28, 2003 Report Share Posted November 28, 2003 yeah, my IAC probably needs cleaning... I just need to find the bastard, lol, and maybe wait for a day without ice fog... Quote Link to comment Share on other sites More sharing options...
getragz34 Posted November 28, 2003 Report Share Posted November 28, 2003 kevin Bacon intake... To funny My Automatic Z34 does the same freaken thing, only when its really cold out (winter time) It would rev to about 2000 then slowly come down and the SES light would come on. When i revd it up a little the RPM's came down slightly and the light would go off. So weird, don't want to be touching anythign right now, to cold out.. Brrr. Anyway I'm working on the alternator so don't need another project right now. Does anyone know for sure what this problem could be ? Thanx Quote Link to comment Share on other sites More sharing options...
jeffcanada Posted November 28, 2003 Report Share Posted November 28, 2003 Could be an open EGR at idle. That's my car's SES of choice. Quote Link to comment Share on other sites More sharing options...
getragz34 Posted November 28, 2003 Report Share Posted November 28, 2003 Going to get some top engine cleaner and see if I can clean it out. Where is the best place to quirt that stuff in ? I have to get alternator put in first, to freaken cold to work on it bbrrrr Later Quote Link to comment Share on other sites More sharing options...
Redfox340 Posted November 28, 2003 Report Share Posted November 28, 2003 Going to get some top engine cleaner and see if I can clean it out. Where is the best place to quirt that stuff in ? I have to get alternator put in first, to freaken cold to work on it You'll want to let the master cylinder brake booster hose suck the cleaner in. Run the car and let the engine take in the cleaner; the car will sputter since air is replaced with cleaner. - Erik Quote Link to comment Share on other sites More sharing options...
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