Cylinder #3 misfire
Posted: Mon Dec 03, 2012 8:01 pm
As I shake my head my co-worker explains to me 'guy your a tech, it's friggin murphy's law, your gonna get the worst problems the car can throw at you'....and I'm starting to believe him. Maybe it's the fact I have access to all the proper diagnostic tools I just naturally complicate things. I've done search upon search and I can't find this one. This post is a log to hopefully help someone else that runs into this nightmare.
So I own a 93 manual rob tuned legacy turbo, I recently aquired a 92 auto legacy turbo with a much better body. Both cars were running great prior to the swap.
Swapped the trans to manual as well as everything that goes along with the rob tune. Done it right as well. No drier hose used here. I've put it together solid enough to trust over long road trips during canadian winters to the middle of nowhere...I icefish alot.
So I get the swaps done, go to fire it up and the engine hydro locks. All 4 cylinders filled with fuel. I've seen this before:
http://bbs.legacycentral.org/viewtopic.php?f=5&t=49377
Run to work and grab a spare maf I got sitting around. Pull the plugs and empty the cylinders of fuel. Car fires up with a heavy miss at all rpms.
Narrow it down to #3 cylinder. I pull the plug wire or the injector connector and no change. Any other cylinder it bogs out and dies.
-check the ecu wiring and ignitor wiring-all good
-change spark plugs- no change
-check injector pulse with a noid light, check spark-all good
-change spark plug wires-same miss
-swap injectors #1 to #3- same miss
-pull the rail, look for leaks or blockages-all good
-vacuum is 13-a little low but shouldn't cause a miss on one particular cylinder
-fuel pressure is about 32-34- maybe a little low but don't think it's eough to cause a miss on one cylinder
-fuel flow-good
-compression is 150 all around- all good
Left it at that last night and went to bed.
Right now my theory is since it was an auto engine there was no guard on the crank pulley for the timing gear. Thinking when it hydro-locked I skipped a tooth or three?!? on the timing belt. I'm pulling the covers tonight to check it.
Any other insight would be appreciated. Hopefully I got it figured with the timing belt.
So I own a 93 manual rob tuned legacy turbo, I recently aquired a 92 auto legacy turbo with a much better body. Both cars were running great prior to the swap.
Swapped the trans to manual as well as everything that goes along with the rob tune. Done it right as well. No drier hose used here. I've put it together solid enough to trust over long road trips during canadian winters to the middle of nowhere...I icefish alot.
So I get the swaps done, go to fire it up and the engine hydro locks. All 4 cylinders filled with fuel. I've seen this before:
http://bbs.legacycentral.org/viewtopic.php?f=5&t=49377
Run to work and grab a spare maf I got sitting around. Pull the plugs and empty the cylinders of fuel. Car fires up with a heavy miss at all rpms.
Narrow it down to #3 cylinder. I pull the plug wire or the injector connector and no change. Any other cylinder it bogs out and dies.
-check the ecu wiring and ignitor wiring-all good
-change spark plugs- no change
-check injector pulse with a noid light, check spark-all good
-change spark plug wires-same miss
-swap injectors #1 to #3- same miss
-pull the rail, look for leaks or blockages-all good
-vacuum is 13-a little low but shouldn't cause a miss on one particular cylinder
-fuel pressure is about 32-34- maybe a little low but don't think it's eough to cause a miss on one cylinder
-fuel flow-good
-compression is 150 all around- all good
Left it at that last night and went to bed.
Right now my theory is since it was an auto engine there was no guard on the crank pulley for the timing gear. Thinking when it hydro-locked I skipped a tooth or three?!? on the timing belt. I'm pulling the covers tonight to check it.
Any other insight would be appreciated. Hopefully I got it figured with the timing belt.