Just finished engine freshen up (std rings,bearings,gaskets,timing chain,etc.,). All measurements within specs, everything by the book. I now have a rough idle and seems to be somewhat rich. Unfortunatly, I have only the usual shade tree tools available. Pulling 16# of vacuum at idle and no check engine light. I'm fairly certain the cam sensor is off so I'm starting from scratch in the morning. Any basic ideas to point me in the right direction would be greatly appriciated.
rough idle after rebuild
- Thread starter SFITurbo
- Start date
don't get frustrated yet, i've been chasing a problem with mine for 3 years.
Anyway how did you adjust your cam sensor, what procedure did you use?
Did you check your crank sensor? also make sure that your IAC and TPS are hooked up and adjusted correctly. check your O2 sensor and make sure the injectors are connected in the right order. Is the chip match to the injectors?
How does it drive otherwise?
Anyway how did you adjust your cam sensor, what procedure did you use?
Did you check your crank sensor? also make sure that your IAC and TPS are hooked up and adjusted correctly. check your O2 sensor and make sure the injectors are connected in the right order. Is the chip match to the injectors?
How does it drive otherwise?
Cam sensor drop in at TDC with window to driver side,the adjusted voltage to 7.08 then ccc to 0 volts. I used the TPS enhancer/calibrater from my wifes GN to check mine- second green light as called for. Crank sensor was installed to go through the first groove with equal spacing between the sensor and crank. IAC ? no clue to what it's doing. Tried the stock chip but went back to the on that was in the car when i got it, no differece either way. Fuel rail wasn't messed with except for new o rings.Car ran like a raped ape prior to tear down,had a huge cloud of white smoke one day(driving sane) and barely made it home. Fixed itself after I cooled off but pulled it out anyway. Never did find evidence of a blown head gasket. Can't road test yet due to drive shaft and brake line (MAJOR rust underneath).Am I missing something obvious?
it needs to be at 25 degrees atdc, trying doing it this way and see what you get. http://www.gnttype.org/techarea/ecmsensors/camsensor.html
this one has a little more detail
http://www.gnttype.org/techarea/ecmsensors/camsensor2.html
this one has a little more detail
http://www.gnttype.org/techarea/ecmsensors/camsensor2.html
Make sure the injector pl,ugs are on the right wires.
test the theory by starting and unplugging the cam sensor to put the system in batch mode. If it runs well then, you may very well have crossed up the wires.
If you never undid the fuel rail, then nevermind. Maybe then verify your grounds, and make sure the MAF isnt in backwards
test the theory by starting and unplugging the cam sensor to put the system in batch mode. If it runs well then, you may very well have crossed up the wires.
If you never undid the fuel rail, then nevermind. Maybe then verify your grounds, and make sure the MAF isnt in backwards
OK,now I've had it.Cam sensor right on,all injectors correct;very rich at idle and plugs fouling out.Barely idles on its own and a slight pop through the intake occasionaly under light revving.Acts like an air leak but nothing showed with the water test around the intake /plenum/injectors/vac lines . Vacuum still around 16 and steady. Changing fuel pressure made no difference. Sticky injectors? Bad H/G seal?Does the crank sensor use the first or second slot? Help me out ! Wifes getting madder every day!
Check the mass air flow, I had same problem a while back. Also scrap the TPS Enhancer IMO it is not worth crap for setting the car up. Get a scanmaster or something and go from the top all way the down TPS, IAC ETC. I also had a crap idle way back on my rebuilt. Turned out like Jim said Mass Air Flow in backwards, car ran but had rough idle and no codes. Took me a while to figure it out.
- Joined
- Nov 24, 2001
#3 and #5 spark plug wires are on the wrong plugs-
153 in the back by the fire wall
426 in the front
i did this once during breaking in a new motor, no problems yet-
153 in the back by the fire wall
426 in the front
i did this once during breaking in a new motor, no problems yet-
Latest update: Bloody knuckles and lots of bruises;checked compression-152-158 on all cyl. FPR would not adjust, got the stock replacement,installed stock chip,adjusted IAC,checked cam sensor and wires again. Don"t run too bad now,Idle hunts a little bit.No more super rich condition. Man these things are finicky. Now I get to install a complete floorpan!! Thanks to all for the help!
All things considered, I believe the FPR was allowing too much pressure to build and forced leak-by past the injectors instead of returning to tank. Outside of the idle speed a little high, I'm happy with the $400 rebuild. One more note, if you ever break a fuel line, just buy the replacement, I've never seen so many bewildered looks when trying to make new ones!
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