'94 LSS...cam sensor-random misfire
#1
Senior Member
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'94 LSS...cam sensor-random misfire
So yesterday I'm waiting at a traffic light, idling fine, light turns green and I take the left turn, accelerating as normal. Engine cuts out, multiple times. I limp to a parking spot and notice the engine never dies, just cuts out and loss of power above around 1500rpm. This is true when accelerating in park also.
I pop the scanner on (it pays to have the scanner handy in a foreign country with this car), and I get the 341 cam sensor and the 300 random misfire, which I suspect was the result of the sensor.
I limp it home, check the wiring this morning, all looks good (just making sure nothing slipped off, frayed, etc.) Starts as normal, no hesitation, etc, idles fine, but when I take off and run the acceleration past 1500rpm, it starts cutting out. Again, engine never dies.
I already ordered the sensor and a couple of other parts, which will take a couple of weeks to get over here. But, I decided to put this on the forum in case there'* something you guys know I should also be checking in the meantime.
I appreciate any opinion at all about the track I'm taking on this, or another track I should be taking. Regards
I pop the scanner on (it pays to have the scanner handy in a foreign country with this car), and I get the 341 cam sensor and the 300 random misfire, which I suspect was the result of the sensor.
I limp it home, check the wiring this morning, all looks good (just making sure nothing slipped off, frayed, etc.) Starts as normal, no hesitation, etc, idles fine, but when I take off and run the acceleration past 1500rpm, it starts cutting out. Again, engine never dies.
I already ordered the sensor and a couple of other parts, which will take a couple of weeks to get over here. But, I decided to put this on the forum in case there'* something you guys know I should also be checking in the meantime.
I appreciate any opinion at all about the track I'm taking on this, or another track I should be taking. Regards
#2
Senior Member
True Car Nut
The cam sensor is problem causing the random misfire, but whether it is or not fixing it is the first step. Once you get it replaced you will be able to focus on any other problems if you still have the misfire.
Fix the obvious stuff first.
Fix the obvious stuff first.
#3
Senior Member
Posts like a 4 Banger
Thread Starter
Okay, new cam sensor went on. AC/Delco, though hecho in Mexico of course.
Fooled me at first. As usual, started fine and idled fine. I drove out of the parking garage and up the exit ramp fine (something it wouldn't do before). Out on the street I accelerated hard, no problem. Once into heavy traffic, and after stop and go for a block, engine stumbled with any load on the accelerator at all. Still the engine never completely dies, just wouldn't take any load. MIL pops up, cam sensor.
I found a spot to pull over in a bus zone and wait an hour for traffic to clear so I could try and nurse the car back home. Tried accelerating in park, no go. Stumbles and cuts out immediately when pressing the pedal. Exhaust stinking of course since the timing was screwed up.
Long story short, I put the old sensor back on and try again. Same, same. So I sit pissed off for awhile and try again. All of a sudden the engine runs fine, but I don't push it, just feather for awhile, at one time up to 1800rpm. When I get near home I romp the pedal a little...no problem. Romp it again, no problem. No MIL, smooth acceleration.
WTH? Old sensor back in, but now the car is untrustworthy to drive. Could it be something simple as they sent me a bad (new) sensor? The old sensor working again is problematic and suggests other.
Anybody have any ideas? I'll be inspecting the wires, pigtail, etc this weekend when I can test drive it again. Any help would be appreciated.
EDIT>Forgot to add that aside from my first post, I haven't seen the random misfire code again.
Fooled me at first. As usual, started fine and idled fine. I drove out of the parking garage and up the exit ramp fine (something it wouldn't do before). Out on the street I accelerated hard, no problem. Once into heavy traffic, and after stop and go for a block, engine stumbled with any load on the accelerator at all. Still the engine never completely dies, just wouldn't take any load. MIL pops up, cam sensor.
I found a spot to pull over in a bus zone and wait an hour for traffic to clear so I could try and nurse the car back home. Tried accelerating in park, no go. Stumbles and cuts out immediately when pressing the pedal. Exhaust stinking of course since the timing was screwed up.
Long story short, I put the old sensor back on and try again. Same, same. So I sit pissed off for awhile and try again. All of a sudden the engine runs fine, but I don't push it, just feather for awhile, at one time up to 1800rpm. When I get near home I romp the pedal a little...no problem. Romp it again, no problem. No MIL, smooth acceleration.
WTH? Old sensor back in, but now the car is untrustworthy to drive. Could it be something simple as they sent me a bad (new) sensor? The old sensor working again is problematic and suggests other.
Anybody have any ideas? I'll be inspecting the wires, pigtail, etc this weekend when I can test drive it again. Any help would be appreciated.
EDIT>Forgot to add that aside from my first post, I haven't seen the random misfire code again.
#4
Senior Member
Posts like a 4 Banger
Thread Starter
UPDATE:
New crank sensor went on (cam sensor replaced already). Responded to the shop and found those a**holes under the hood revving the engine, popping, misfiring, etc. Idiots. I mean, what exactly is being diagnosed when you rev an engine in park to 4-5K rpm? Nothing. Seventeen year old car with 193K on the ticker and they're abusing it. It'* a wonder it didn't throw a rod.
Anyway, back on track. Still misfiring after the engine warms up, still the cam/crank sensor code (0341).
I go back the next day and have them pop the ICM off of it (new Delphi, six months ago), and put the old one on (which I had saved). I get in the car and he says go ahead and start it. Misfiring, no start. All the goof had to do is remove the 3 coils and keep them in order. I already know he screwed it up and switched coils. So I fix that and start the car. Been driving it for a full day now, no problems.
Recap: Consistent cam/crank code P0341 when misfiring after warmup.
Solution: Ignition Control Module.
$105 bucks, Delphi. Dead after six months. 17yr old ICM, works fine. Grrrr.
EDIT>Also, this afternoon I pop the hood and notice the reservoir on the power steering pump is slick with fluid. I take the cap off and those clowns had filled it to the brim. Enough pressure that it was blowing out under the cap while driving. Idiots.
New crank sensor went on (cam sensor replaced already). Responded to the shop and found those a**holes under the hood revving the engine, popping, misfiring, etc. Idiots. I mean, what exactly is being diagnosed when you rev an engine in park to 4-5K rpm? Nothing. Seventeen year old car with 193K on the ticker and they're abusing it. It'* a wonder it didn't throw a rod.
Anyway, back on track. Still misfiring after the engine warms up, still the cam/crank sensor code (0341).
I go back the next day and have them pop the ICM off of it (new Delphi, six months ago), and put the old one on (which I had saved). I get in the car and he says go ahead and start it. Misfiring, no start. All the goof had to do is remove the 3 coils and keep them in order. I already know he screwed it up and switched coils. So I fix that and start the car. Been driving it for a full day now, no problems.
Recap: Consistent cam/crank code P0341 when misfiring after warmup.
Solution: Ignition Control Module.
$105 bucks, Delphi. Dead after six months. 17yr old ICM, works fine. Grrrr.
EDIT>Also, this afternoon I pop the hood and notice the reservoir on the power steering pump is slick with fluid. I take the cap off and those clowns had filled it to the brim. Enough pressure that it was blowing out under the cap while driving. Idiots.
#5
Senior Member
Posts like a 4 Banger
Thread Starter
Good Lord, yet another fix.
So the car has idled fine, but a little too roughly since I drove it away from the shop. I didn't mention before that while there I had them pull the plugs and they were incredibly fouled by unburnt fuel. No problem, as I had a set of AC/Delco in the trunk. They put them in.
So back to the rough idling. I start pulling the plugs they put in and find the three in the cylinders at the front of the car have been 'super' torqued (for lack of a better word). I crank them out and all three are down to about a .20 gap. WTF? The back three are fine.
I regap the front ones back to .60, and reinstall all of them. My guess is that they cranked them down so hard that the pistons slapped the electrodes. They couldn't get good enough leverage to torque the rear plugs to what must have been 80-100 foot pounds. Geez.
Rant over
So the car has idled fine, but a little too roughly since I drove it away from the shop. I didn't mention before that while there I had them pull the plugs and they were incredibly fouled by unburnt fuel. No problem, as I had a set of AC/Delco in the trunk. They put them in.
So back to the rough idling. I start pulling the plugs they put in and find the three in the cylinders at the front of the car have been 'super' torqued (for lack of a better word). I crank them out and all three are down to about a .20 gap. WTF? The back three are fine.
I regap the front ones back to .60, and reinstall all of them. My guess is that they cranked them down so hard that the pistons slapped the electrodes. They couldn't get good enough leverage to torque the rear plugs to what must have been 80-100 foot pounds. Geez.
Rant over
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