99 PA starts weird/now a misfire

[HotZ28]

Please refrain from starting a new thread with the same subject as your original thread, it only creates confusion! You're latest thread has been merged here, to keep the discussion on the same sheet of music. Thanks

[dadooishome]

Got a 98 PA with 240k that now has "Cylinder #1 misfire" code. Happened 3 times the past 10 days. Each time I drove the car 5 minutes, shut it off a short time, then it started on 5 cylinders and ran that way for 5-30 minutes before kicking in cylinder #1. Last fall I replace plugs and wires. So with the same coil firing 2 cylinders, why is *only* #1 misfiring?

If I swapped the wires on the same coil (using the 'waste' spark), would that be a good wire/plug check?

How does the OBDII ~know~ it is #1 cylinder misfire? Does the knock sensor, sense both a knock and a lack of a normal firing in each cylinder?

I assume OBDII can measure the current flow on each injector and would generate a diffent code for a lack of fuel.

[hammerhankinson]

Originally Posted by dadooishome

Got a 98 PA with 240k that now has "Cylinder #1 misfire" code. Happened 3 times the past 10 days. Each time I drove the car 5 minutes, shut it off a short time, then it started on 5 cylinders and ran that way for 5-30 minutes before kicking in cylinder #1. Last fall I replace plugs and wires. So with the same coil firing 2 cylinders, why is *only* #1 misfiring?

If I swapped the wires on the same coil (using the 'waste' spark), would that be a good wire/plug check?

How does the OBDII ~know~ it is #1 cylinder misfire? Does the knock sensor, sense both a knock and a lack of a normal firing in each cylinder?

I assume OBDII can measure the current flow on each injector and would generate a diffent code for a lack of fuel.

Yeah I would assume it would as well. When I had a misfire last summer and was checking the fuel injectors I left one unplugged on accident and when I started the car it gave me a "fuel injector malfunction" code. I have a book that list's all the codes an OBD-II sensor lists and it has codes for all the injectors just like it has codes for each cylinder that misfires.

It sounds like you're having the same problem I am. I've tried everything me and the book can think off. Just replaced everything not even 9 months ago but the ICM tests good, coils have correct resistance but they're giving off a yellow or weak spark and the plugs are good since I swapped the cylinder 1 and 2 plugs but I'm still getting a cylinder 1 misfire. I had to give in and take it to a shop this morning. I'll post as soon as they figure out what the problem is so hopefully it will solve your issue as well.

Must be something tricky because I dropped it off over 3 hours ago and haven't heard from them.

[Scrapper]

Originally Posted by hammerhankinson

Yeah I would assume it would as well. When I had a misfire last summer and was checking the fuel injectors I left one unplugged on accident and when I started the car it gave me a "fuel injector malfunction" code. I have a book that list's all the codes an OBD-II sensor lists and it has codes for all the injectors just like it has codes for each cylinder that misfires.

It sounds like you're having the same problem I am. I've tried everything me and the book can think off. Just replaced everything not even 9 months ago but the ICM tests good, coils have correct resistance but they're giving off a yellow or weak spark and the plugs are good since I swapped the cylinder 1 and 2 plugs but I'm still getting a cylinder 1 misfire. I had to give in and take it to a shop this morning. I'll post as soon as they figure out what the problem is so hopefully it will solve your issue as well.

Must be something tricky because I dropped it off over 3 hours ago and haven't heard from them.

i had mine put on machine at good year twice and all they could tell me there was a ground wire braking down it ran good on machine until unhooked it and it was throwing off all kinds of sensors so i thought and thought and finaley said i was going to get new module under coil pack and it curred it. but yet they couldn't tell me it was module. but you say yours tested good?

[hammerhankinson]

Yeah if you take the ICM into AutoZone they can test it for you. I didn't know that either until I went in to ask about exchanging it on the warranty. I had a misfire last summer and my dad (who has worked on cars his whole life) and I couldn't figure it out at all. Thought it was a burnt valve and it was just the ICM.

BUT FINALLY have the current misfire problem solved. It was the fuel injector all along. So apparently you won't always get a "fuel injector malfunction" code if the injector is bad. I didn't do an ohm test on it but heard it clicking and just assumed it was fine since I thought I would get that code if it wasn't. Glad to have the problem solved but kind of disappointed I couldn't figure that out on my own.

Thanks to all who replied, it was helpful!