Hey everyone. I replaced the map sensor because there was a code for it. I am getting random slight misfires seems to be worse when the vehicle is cold. I can use my solus edge and watch a cylinder misfire. They all are doing this the car does not feel like its running bad. The wires and plugs are all fairly new. I am actually at a loss. The car isn't throwing a code yet for it but i can see the misfires on the counter.
pt cruiser multiple misfire
- Thread starter ram_man
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It might be an ignition coil going bad.
How old are the plugs?
JHZR2
Staff member
Is there a distributor on that car? I'd guess no because my mother's 97 Breeze had distributor less, but thinking out loud.
01 celica gt, would misfire to the point that it was only noticeable when the A/C was on.
The codes were ever set, the A/C would never cool to 40 Degrees, upon inspection, one of the ignition coils had somehow lost the spring(maybe a 1zzfe design only, not sure), though the coil was full functioning, without the spring the current wasn't transferring effectively to the spark plug thus causing a "mild" misfire.
Replacement of the ignition coil, solved the problem, installing a small spring would have worked as well.
The codes were ever set, the A/C would never cool to 40 Degrees, upon inspection, one of the ignition coils had somehow lost the spring(maybe a 1zzfe design only, not sure), though the coil was full functioning, without the spring the current wasn't transferring effectively to the spark plug thus causing a "mild" misfire.
Replacement of the ignition coil, solved the problem, installing a small spring would have worked as well.
Nick1994
$100 site donor 2024
My step-moms 2005 PT Cruiser had a few misfires over the couple years she had it. It burned out a spark plug and got new plugs and wires. A few months later the same thing happened, got new plugs and wires and it fixed the problem. Then a couple months later she traded it in.
Originally Posted By: ram_man
Hey everyone. I replaced the map sensor because there was a code for it. I am getting random slight misfires seems to be worse when the vehicle is cold. I can use my solus edge and watch a cylinder misfire. They all are doing this the car does not feel like its running bad. The wires and plugs are all fairly new. I am actually at a loss. The car isn't throwing a code yet for it but i can see the misfires on the counter.
2.4L?
If so, check the ignition module on top of the engine. On our '04 Wrangler (similar engine) there was corrosion on the unit where the plug wires attached. It's a $90 part IIRC and a 20 minute fix.
Hey everyone. I replaced the map sensor because there was a code for it. I am getting random slight misfires seems to be worse when the vehicle is cold. I can use my solus edge and watch a cylinder misfire. They all are doing this the car does not feel like its running bad. The wires and plugs are all fairly new. I am actually at a loss. The car isn't throwing a code yet for it but i can see the misfires on the counter.
2.4L?
If so, check the ignition module on top of the engine. On our '04 Wrangler (similar engine) there was corrosion on the unit where the plug wires attached. It's a $90 part IIRC and a 20 minute fix.
What kind of plugs?
Yeah, what plugs?
If they are NGK or Autolite with varnish on the terminal, you may have to file that stuff off ( depending on the secondary wire to plug interface.
This came with Champion OEM?
And yes, check for vacuum leaks and EGR sticking open partially.
Poor gas can cause high misfire count.
If they are NGK or Autolite with varnish on the terminal, you may have to file that stuff off ( depending on the secondary wire to plug interface.
This came with Champion OEM?
And yes, check for vacuum leaks and EGR sticking open partially.
Poor gas can cause high misfire count.
I'd do all the usual suspects, but where did you get your gas last?
Random misfire codes are a headache when your gas is the culprit.
Pull the plugs and inspect the gaps, but be sure to gas up at a brand new Shell station to get a baseline.
Random misfire codes are a headache when your gas is the culprit.
Pull the plugs and inspect the gaps, but be sure to gas up at a brand new Shell station to get a baseline.
I cleaned tb. Replaced coil, cam sensor, intake plenum gasket, replaced wires and plugs. 2 plugs were carbon tracked. And lastly crank sensor. I did a battery disconnect with the scan tool and after crank sensor there was no more misfires. I drove 20 miles and then shut it off for 5 minutes and refired it and frogged the gas pedal and there it was misssing again. So i cleared everything adaptive fuel trims every thing that my solus edge can reset. It sat and i tried for 15 minutes and it hasnt done it again so i let it run for 20 more minutes and then checked it and not one misfire. I frogged the pedal several times and no misfires..whatever it is or maybe it wad the crank i should have just reset everything but if not whatever it is is fine once reset atleast for a little while.
Try loading the car, turn on Rear Defrost, Headlights, Radio up to medium volume, everything you can.
Then have a buddy at work check the charging voltage with a multimeter set to VDC as you roll down one window and see if it goes up to 14VDC.
You can try at 3k Rpm as well, and just note the VDC he reads.
Scan for codes as well, make sure your EGR valve is working etc... If the EGR valve is stuck open that could be causing issues.
Man, I forgot how many millions of things there are to check for random misfire!!
If all that is ok, maybe check with a propane torch (unlit for people who don't know this trick) and track down a vacuum leak.
Then have a buddy at work check the charging voltage with a multimeter set to VDC as you roll down one window and see if it goes up to 14VDC.
You can try at 3k Rpm as well, and just note the VDC he reads.
Scan for codes as well, make sure your EGR valve is working etc... If the EGR valve is stuck open that could be causing issues.
Man, I forgot how many millions of things there are to check for random misfire!!
If all that is ok, maybe check with a propane torch (unlit for people who don't know this trick) and track down a vacuum leak.
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Any updates? Did you change the Knock Sensor?
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