LOST JEEPS
http://www.lostjeeps.com/forum/phpBB3/

GM 4.3L V6 - P0302 (Cylinder 2 Misfire) Help
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=70&t=41723		 Page 1 of 1
Author:  ihatemybike [ Mon Mar 30, 2009 11:28 pm ]
Post subject:  GM 4.3L V6 - P0302 (Cylinder 2 Misfire) Help
Grumpy needs your help. For quite some time Grumpy has set the P0302 (Cylinder 2 Misfire) code. Usually misfire codes are due to dirty injectors/sticky poppets. I've done Seafoam and the GM Fuel System Treatment Plus, to no avail. Since the injector/poppet is usually the cause, I decided to swap the injector for cylinder 2 with another cylinder. This in theory should move the misfire to another cylinder, if the injector is indeed the problem. Having completed the swap between cylinder 2 and 4, Grumpy still sets code for cylinder 2. Using the ScanGaugeII, I have discovered that if I don't let the throttle position sensor (TPS) hit 0 the code won't set. Playing with that idea I adjusted the idle to roughly 1000 RPM. Yeah, the van idles at 25 mph. Driving around, I see the computer recalculates where TPS 0 is and despite the much higher idle the code will set. However still, if I don't let the TPS hit 0 the code doesn't set. Anyone with GM experience have any ideas?

Here's a list of causes for P0302 errors and if I've done something about it:
* Faulty spark plug or wire - New installed
* Faulty coil (pack)
* Faulty oxygen sensor(s)
* Faulty fuel injector - Moved injector to different cylinder
* Burned exhaust valve
* Faulty catalytic converter(s) - Exhaust does not smell like rotten eggs
* Running out of fuel - Fuel pressure is good
* Poor compression - Wife hasn't reported smelling burnt oil after following the van.
* Defective computer
Author:  tjkj2002 [ Mon Mar 30, 2009 11:36 pm ]
Post subject: 
Do you have the normal distributor or do you have the one with the 3 wires pointing straight out on both side of the cap?You shouldn't have a coil pack per say on a 4.3,could be in the distributor and /or a bad PCM driver.
Author:  ihatemybike [ Mon Mar 30, 2009 11:55 pm ]
Post subject: 
3 wires pointing to each side. The cap and rotor are in good condition and there was no noticeable play in the distributor's bushing. The more I think about it, the more I think it's the PCM. Those things aren't cheap. Does AutoZone test those?
Author:  tjkj2002 [ Tue Mar 31, 2009 12:04 am ]
Post subject: 
ihatemybike wrote:
3 wires pointing to each side. The cap and rotor are in good condition and there was no noticeable play in the distributor's bushing. The more I think about it, the more I think it's the PCM. Those things aren't cheap. Does AutoZone test those?
No they can't,dealership only but with a cap and rotor the PCM really has nothing to do with it anyway.Most likely a bad cap but still could be a some valve issues on #2.
Author:  ihatemybike [ Tue Mar 31, 2009 12:12 am ]
Post subject: 
Guess I'll borrow Green's cap and rotor to see what happens.
Author:  TAHOE [ Tue Mar 31, 2009 8:59 am ]
Post subject: 
Aaron, have you done a compression check on Cyl 2? It could be a remote possiblility that after it warms up, it is leaking passed one of the valves. Even if you have changed the plug wires, could also be one of those. My 95 Stro had a new set of AC Delco wires on it, started missing about 6 months after install....looked like a flashing Christmas tree under there in the dark. My first thought was coil, but then you would be having misfires over all cyls. I wuold still be leaning towards a fuel issue or compression issue in that cyl.
Have you talked to James from ASV yet? He's the expert.
Author:  ihatemybike [ Wed Apr 01, 2009 9:33 am ]
Post subject: 
Swapped the cap and rotor from Green into Grumpy yesterday, no change.

Went to emissions to fail anyway, stupid emissions.

I'll borrow Green's oxygen sensor tonight and see if that helps.
Page 1 of 1 All times are UTC - 5 hours [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/