Engine loping/misfiring, lost power, stuttering. HELP please.
08-22-2009, 07:48 PM
#1
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Engine loping/misfiring, lost power, stuttering. HELP please. This is a bit of a story, but I want all the details here, so here goes.
About two weeks ago, I noticed that, when I started my car already hot (after going into a store for a short errand or thereabouts), that it would lope, be missing power, and seem to be just all out of whack. What was previously a nice clean V8 sound suddenly had become a *BLUB BLUB BLUB BLUB BLUB* (fighting to make power at all) that I could punctuate by giving a good bit of gas, suddenly causing the car to take off and feel like normal (briefly), only to go back to that. I found that trying such a tactic too often resulted in a flashing SES light for a bit. This behavior would usually go away within 5 minutes, and then the car would drive like normal.
This would NEVER occur when I was starting it cold.
Now it has been getting progressively worse, and now the car is doing that even when I start it cold, and is not adjusting back to normal quite so much as I drive more.
Today as I drove it home from getting an alignment & front tires, I noticed the "ASR Off" light on, and I couldn't switch it back on using the switch. However as soon as I got into the driveway, the light went out and the switch functioned like normal again. Weird ****.
Since I was planning a tune-up already, I just did the following:
Oil Change
Oil filter
Clean air filter
New spark plugs (if I could get 5 minutes with the guy who laid out that engine compartment... )
New plug wires
New o2 sensors
A new fuel filter goes on tomorrow morning, but I don't think that's what's causing this. I'll also clean the MAF sensor.
Sure enough, I start it up and it's the same loping, stuttering crap. I am totally stumped and am wondering what in the blue f#%@ is causing this.
About two weeks ago, I noticed that, when I started my car already hot (after going into a store for a short errand or thereabouts), that it would lope, be missing power, and seem to be just all out of whack. What was previously a nice clean V8 sound suddenly had become a *BLUB BLUB BLUB BLUB BLUB* (fighting to make power at all) that I could punctuate by giving a good bit of gas, suddenly causing the car to take off and feel like normal (briefly), only to go back to that. I found that trying such a tactic too often resulted in a flashing SES light for a bit. This behavior would usually go away within 5 minutes, and then the car would drive like normal.
This would NEVER occur when I was starting it cold.
Now it has been getting progressively worse, and now the car is doing that even when I start it cold, and is not adjusting back to normal quite so much as I drive more.
Today as I drove it home from getting an alignment & front tires, I noticed the "ASR Off" light on, and I couldn't switch it back on using the switch. However as soon as I got into the driveway, the light went out and the switch functioned like normal again. Weird ****.
Since I was planning a tune-up already, I just did the following:
Oil Change
Oil filter
Clean air filter
New spark plugs (if I could get 5 minutes with the guy who laid out that engine compartment... )
New plug wires
New o2 sensors
A new fuel filter goes on tomorrow morning, but I don't think that's what's causing this. I'll also clean the MAF sensor.
Sure enough, I start it up and it's the same loping, stuttering crap. I am totally stumped and am wondering what in the blue f#%@ is causing this.
Last edited by Emfuser; 08-22-2009 at 11:10 PM.
08-22-2009, 11:55 PM
#2
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I've had similar problems with my car but it didn't stutter like you are explaining.
I replaced plugs, checked injectors, coilpacks, wires, replaced pcv valve, fuel filter, oil change.
I also replaced my knock sensors and the harness for them.
My car is riding much much more smoothly.
What codes are you showing?
I replaced plugs, checked injectors, coilpacks, wires, replaced pcv valve, fuel filter, oil change.
I also replaced my knock sensors and the harness for them.
My car is riding much much more smoothly.
What codes are you showing?
08-23-2009, 11:36 AM
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Ok, I've got myself an Actron 9185 (love the graphing function on this thing).
The codes that were in the system (aside from disabling CAGS) were P0121 Throttle Position Sensor/Switch A Circuit Range/Performance Problem and an o2 sensor no activity code. I cleared the codes and ran the vehicle, and only the !CAGS code was there. One thing I did notice was that it was consistently running 25-30 degrees of timing advance.
I'm gonna go ahead and finish swapping my fuel filter and take it out. I'll let you guys know what I find. I'm still learning this nifty little scanner.
The codes that were in the system (aside from disabling CAGS) were P0121 Throttle Position Sensor/Switch A Circuit Range/Performance Problem and an o2 sensor no activity code. I cleared the codes and ran the vehicle, and only the !CAGS code was there. One thing I did notice was that it was consistently running 25-30 degrees of timing advance.
I'm gonna go ahead and finish swapping my fuel filter and take it out. I'll let you guys know what I find. I'm still learning this nifty little scanner.
08-23-2009, 02:35 PM
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I found the #1 spark plug just a little lose. I set that into place and she was running great.
It seemed the tune-up fixed the problems I was having prior. Once I had the connections back into place properly, all was well.
Thanks for the help.
It seemed the tune-up fixed the problems I was having prior. Once I had the connections back into place properly, all was well.
Thanks for the help.
08-24-2009, 09:30 AM
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Glad you found the problem the gf's z was having the same problem started after we chenged out the drivers side manifold (broken cat flange) wasnt throwing codes but had the came rough idle and lope we replaced the TPS IAT sensors and plug wires with no luck...took out the spark plugs and it turned out while putting the manifold in we bumped a plug and the thing was cracked.....**** had us stumped for a week...lol thank god for ls1tech!
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08-24-2009, 05:53 PM
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Hmmm... I'm thinking that my messing with codes and whatnot has caused CAGS to kick back in. Twice I've started my car cold and been restricted to 1st, 4th, and 6th gear until I've driven a bit and the car has warmed up.
