I need all the help I can get. This is my first post on here so I’ll try not to make it too long. I have a 97 sport with the 4.0. I have a multiple cylinder misfire and specially 1,3,6. I have a new set of plugs, wires, and distributor cap and button. It has a definite misfire that can be felt and heard when cranked cold and when warmed up. I’ve also put in a new mopar crank sensor and just replaced the thermostat to the factory 195* someone had a 180* in it. Thanks for any help that I may get. I just don’t want to throw a ton of more money at it and nothing fix it.
Multiple cylinder misfire
- Thread starter Ltomclrk
- Start date
See this thread:
https://wranglertjforum.com/threads/misfire-on-cylinder-1-cylinder-2-and-random-misfire.68506/
I posted the section out of the 2005 Powertrain Diagnostic Procedures Manual (it's for the newer NGC PCM, though, so it's not 100% applicable to yours) that covers diagnostic testing for the cylinder misfire DTCs. Unfortunately, you need access to a DRB III or equivalent to do all the diagnostic tests.
https://wranglertjforum.com/threads/misfire-on-cylinder-1-cylinder-2-and-random-misfire.68506/
I posted the section out of the 2005 Powertrain Diagnostic Procedures Manual (it's for the newer NGC PCM, though, so it's not 100% applicable to yours) that covers diagnostic testing for the cylinder misfire DTCs. Unfortunately, you need access to a DRB III or equivalent to do all the diagnostic tests.
My bet is your CPS (crankshaft position sensor) has gone bad. Avoid any store brand CPS, go with a high quality replacement as it's a critical sensor.
No cat just muffler. I had one and it was doing this before it was taken out.
Whoops just noted your additional statement on that. Can you tell us exactly what brand and MODEL # spark plugs are installed? Some types of platinum plugs can cause misfires.
Awesome I’m to the point I’m going to do a compression test and hope I don’t have the dreaded weak valve springs. After I do a carbon clean up through the intake.
My 97 had the weak valve springs, it regularly had 3-4 cylinder misfires until I had the springs replaced.
Sounds about like my luck I guess I know what I’ll be doing very soon
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