I have been having issues with my rpms jumping around while driving and it is not the gauge becasue I can feel the motor give out. It feels like a cylinder missing but worse because the car will stall occasionaly now. It got to the point where the car would stall at 10 to 15 mph sporadically. I checked all of the plugs and wires and they looked fine, but I replaced the plugs anyway. Still have the same problem and today when driving it stalled when pullling up to a stop sign and then when I went to start back up there was a huge backfire and the issue still seems to be the same with rpms jumping down when driving. The car goes from cruising fine to a rough running mess. I'm thinking it may be timing related, but any input would help.
RPM Jumping and Backfire
- Thread starter trbodon21
- Start date
I re adjusted the cam sensor and haven't had any backfireing issues, but it is still stumbling when cruising and when coming to a stop. I can keep it from stalling by giving it more gas. My fuel pressure is fine as well. I was thinking maybe coil pack? Any suggestions
Alaskabuick
Member
- Joined
- Jul 4, 2004
cam sensor
Did you check your cam sensor to make sure you cannot turn it by hand? My was doing the same thing yesterday, pulled the cam sensor and it looked good, but I cold turn it by hand. Their is a little keeper tab that breaks off and allow the cam rotor to turn. Make sure it is solid and snug.
Den
trbodon21 said:
Did you check your cam sensor to make sure you cannot turn it by hand? My was doing the same thing yesterday, pulled the cam sensor and it looked good, but I cold turn it by hand. Their is a little keeper tab that breaks off and allow the cam rotor to turn. Make sure it is solid and snug.
Den
Alaskabuick
Member
- Joined
- Jul 4, 2004
cam sensor adjust
Just a thought, did you make sure you were on the compression stroke at 25 degrees ATDC of #1 cyl?
I have been 180 off before.. just might want to double check?
Dennis
trbodon21 said:
Just a thought, did you make sure you were on the compression stroke at 25 degrees ATDC of #1 cyl?
I have been 180 off before.. just might want to double check?
Dennis
Alaskabuick
Member
- Joined
- Jul 4, 2004
yep
Thats true for sure..
One thing is denfinate these cars need attention all the time.
Den
trbodon21 said:
Thats true for sure..
One thing is denfinate these cars need attention all the time.
Den
So I tested the coil pack hot and found 18K across the 5-2 coil. I have another coil pack so I put it on to see If anyhting changed and it was the same and those coils were all about 12K-13K hot. The RPM is still jumping around when cruising,declerating, and accelerating. One note is that it doesn't happen until the car is at operating temperature. I am going to try to find a module today at the junk yard and see if that does anything.
Me too man. My bfiring started after chasing a C-5 . I thought I over -revved and floated valves, but it now does it after hot, and after a hiway romp. It will recover after some easy driving, but those backfires are wicked load! For awhile, Ive had missing on low speed cruise, say just like a plug wire would do on a normal car, but i know its not that, because it doesnt miss under load. Its always somethin.
Good luck
ps-anyone know if bfiring will hurt turbo?
Good luck
ps-anyone know if bfiring will hurt turbo?
I disconnected everything and checked sensors and all connectors, inspected thrttle body and up pipe. All looked good. Re seated wiring harnes to DFI adapter. Everything is hooked back up, but problem still persists. Also the car doesn't have to be hot anymore for this to happen. It stumbled a few minutes after I srated it up. I then took the car out for a ride I got on it a little and the engine cut out for a second and then started pulling again. I'm in a rut...
Salient point, AlaskaB. I found my problem, it was exactly that little keeper tab you described. My trigger wheel still was holding, but the remnant of the keeper was in the hall effect switch, as it is a magnet. Of course, I removed the 1/2 millimeter little flake of metal that was caught in the magnet. How the hell does this thing ever break? I tightened the screw that holds the breaker plate, and it never had been loose per-se. But, I do feel as if the trigger wheel still is able to move on the shaft a tiny bit.Alaskabuick said:
I do know that the sliver of metal was the problem...It fixed the dead miss problem. It still does have more hunting at idle and more missing at 2000 rpm than it should, but there is no comparison. It used to buck like someone had turned the distributor in a regular car too advanced... (too much timeing, a dead miss). This, was intermittant. Now my missing is more "fluffy" and there is no backfire at all.
I think Ill put a divit in the trigger wheel, and maybe some threadlock on the screw.
This can teach an oldtimer that the cam sensor gives problems like a distributor can.
