Miss fire

[3.8lcoty]

okay with my miss fire i have already changed the coils plugs and wires, took the injectors out and cleaned them good with carb cleaner.

But when i took the injectors out to clean them it wasn't miss firing and i put them back in and 30 miles later it started again,so i tried to unplug the first 3 plugs on the coils one at a time and no difference in idle so i tried an injector and still no difference.

i was going to try the icm next what do you guys think and are our cars big on the computer going out to?

[SlasherVRGR]

Have you tried fuel filter? If its choking you could get some lean misses.

I just recently fixed my miss. Mine was wires though, 4 of the six boots were cracked and falling apart and 2 of the wires melted to the manis lol.

I had some high temp rtv as I was planning on doing my header install too so I coated the boots with that, hopefully adding some heat resistance.

Sent from my MB870 using Tapatalk

[3.8lcoty]

Re: Miss fire

All my wires are new and a fuel filter will be the next thing to try with the icm

[3.8lcoty]

Re: Miss fire

okay i put in a used icm and there was no change but between my old icm and my coils was some surface moisture where the little rubber pieces are at the prongs

and my miss fire is a constant rough miss fire with the car having little power and the check engine light flashing the whole time im driving, plus im getting like less than or equal to 15 mpg all the time now.

but the miss started as a miss on cylinder 3 not rough just flashed the check engine light at idle then went to a rough miss fire all the time for about 30 min and would stop and the car would get back all its power in a spit second like i hit a nitrous switch to miss firing for days and now weeks.

but it started off by throwing cylinder 3 miss to random miss/bad cat code/o2 sensor bad code and i can smell the strong smell of gas when i crank it.

and i have cleaned the injectors with carb clenaner, replaced all 3 coils a wile back then another new coil on the cylinder 3 coil and all the plug wires and plugs and the cylinder 3 plug and wire again just to make sure and the icm.

[3.8lcoty]

Re: Miss fire

fuel additives use to help then sea foam would stop it and now nothing stops it

[3.8lcoty]

Re: Miss fire

Any advice would be greatly appreciated

[Hib Halverson]

Re: Miss fire

Have you run the fuel pressure tests in the Service Manual?

If so, what were the results?

[3.8lcoty]

Re: Miss fire

Have you run the fuel pressure tests in the Service Manual?

If so, what were the results?

I have not ran that yet but I just replaced the fuel pump a month ago thinking about the fuel filter next

[3.8lcoty]

Re: Miss fire

As of today the codes I got were p0442 p0174 p0102 p0300 p0147

[Hib Halverson]

Re: Miss fire

P0102
That's a MAF sensor fault. The sensor has failed low, ie: it output a signal below 800Hz for more than half a second. If the sensor is working, it can't do that so the ECM assumes a failure.

I'd start by attempting to clean the MAF and checking it's wiring. If you find no problems there, you need the FSM for your model year. Once you have it follow the diagnostic steps for that code.

P0147
O2S heater fault, likely the rear sensor

Trouble shoot the heater circuit for sensor that's after the cat.

P0174
System lean on bank 2 (pass. side) Fuel trim is at the rich limit, ie: the system is adding as much fuel as it can to the left bank but it's still lean.

The system can be lean for a variety of reasons but the first to look for is a vacuum leak affecting only the left bank. If you don't find a leak, check to make sure all the injectors are working. Also, cleaning injectors with carb cleaner is likely not going to solve the problem.

P0300
Random misfire

Tons of reasons for random misfire. Could be ignition, could be the same cause for P0102 and P0174. Could be something else.

P0442
Evap system fault

Inspect the EVAP system for missing test caps or leaks. If you don't find any, you need the FSM for its EVAP diagnostic info.

Good luck.

[3.8lcoty]

Re: Miss fire

Thanks for the info^

[3.8lcoty]

Re: Miss fire

I found out how to stop it today, what I do is have the car off pull one plug wire off the coil then start the car up rev to two grand for a second turn the car off then plug it back up then do the next plug the same way till I have done all 6 then I check and make sure there all clicked down then I start it up and there is no miss fire, and its the smoothist idle I have had in a long time

[3.8lcoty]

Re: Miss fire

With it not missing I drove around a little and I had it start missing again after I turned the car off and I did the trick again and it stoped miss fireing again

[Hib Halverson]

Re: Miss fire

With it not missing I drove around a little and I had it start missing again after I turned the car off and I did the trick again and it stoped miss fireing again

WTF?
That's the strangest thing I've ever heard.

I'm convinced...
Lada Gaga has been sent to earth to infiltrate human culture one sequin at a time and she's started with your car.
:)

[3.8lcoty]

Re: Miss fire

Haha man it is weird