It happened again..........CODE P0301!!!

[Hardwareman]

Well I bought a new MAF sensor last night to the tune of $110.00 and left for work this morning. My CEL started flashing again so I turned around and came back home to check what the code was. Sure enough it was the dreaded P0301 that I've been getting for a while now. I removed the MAF sensor because I'm going to try to return it (please let them take it back) and fired up the motor.

I grabbed cylinder #1 plug wire to pull it off and got the shock of my life!

What in the world is going on here guys?

I think I'm going to swap out that fuel injector today and see what happens.





Allen

 

[Hardwareman]

Thank god AutoZone returned the MAf sensor!

I just got back with TWO brand new coil packs and installed them. No change! It still has a slight misfire at idle. When I rev the engine up to like 4,000-5,000 rpm's and then let it return to idle it shakes a little and then resumes normal idle a few seconds after.

The miss is still there however. When I unplug my fuel injector from cylinder #1 the engine idle DOES decrease.

Could this be my PCM? Please guys, I'm begging you now. The wife and I are already calling car dealers.




Allen

 

[Hardwareman]

Removed my PCM now and took the bottom cover off to look inside. Man, this thing looks like the inside of my desktop computer!! One area appears to be slightly burnt looking. I showed my wife and she seems to agree. Maybe it is the PCM.

I already ate the two coil packs for about $100. I really can't afford to eat $130.00 for a PCM if that is'nt it you know? But......I'll never know if that's it or not unless I replace it and the junkyard does'nt have any. Oh god......please.




Allen

 

[Joelzme]

Hey man,

Sorry you're still having major problems. Perhaps the PCM is the way to go. I did find this on P0301 errors and thought you might want to check it over:

http://www.engine-light-help.com/P0301-check-engine-light.html

Good luck tho. Did the all data stuff help out any?

Joel

 

[Hardwareman]

I looked at it but to be honest I get confused a little by all the diagrams......hahaha. I think I'll check it out further though later tonight. It's actually quite informative as far as telling you what you need to do to thouroughly check a system out.

I think I'm going for fuel next. I'll check fuel pressure and the return line for kinks and all that. I just went to Wally World and picked up a fuel filter just for piece of mind you know? After that I'll do a compression and leakdown test on #1 cylinder, as the tools are cheap at Harbor Freight or even free to rent at AutoZone. It's not running that bad really but sometimes it gets a mind of it's own and runs horrible for a few minutes at idle is all. I know the misfire at idle has something to do with it.

Maybe it is fuel cause after I rev it up for an extended period it shakes a little before returning to a smooth idle. But then would'nt it do that under load when driving? Who knows?

I figure I'll keep driving it while I rebuild my old 2.3 in the garage, while in the meantime replacing parts and continuing checking things out.



Allen

 

[tony1w]

1997 4cyl ranger

I've been having this problem for a long time p0301. At one point it clogged up my cat. i'VE done all the plugs, wires, coilpacks, etc. Still having that issue. Would you think this had anything to do with the EGR sys? maybe sticking open or lightly open?

 

[Mark_88]

This was actually fixed...wasn't the EGR...think it was the MAF or MAP sensor...see the other threads by hardwareman...or he might see this and give you his fix...

 

[b2r]

have you check your fuel injector they could be partially block !!! 2 thing to check when you have a specific cylinder missfire : ignition system ( plugs, ignition wire, coil pack) and your injector ( dirty or full of gum or not fonctionning properly... check the injector resistance and compare to the other 3) also check to make shure your getting voltage to your injector ( By memory the red or brown wire) the injector are controlle by ground . I' m pretty sure the egr wouldn't be the trouble because a stuck egr valve will give you a p0300 as for all cylinder miss fire. hope I can help

 

[tylerh]

hardwareman try the 2.5 comp if you still have it

 

[Hardwareman]

It actually ran worse with the 2.5 computer when I originally installed the motor, but I no longer have it anyhow. I would think if I had the 2.5 computer and wiring harness installed I would also need the instrument cluster from the same year Ranger because the CEL light is in a different location and the wiring eventually passes through there.

I've done a cluster swap in the past and have had issues with this, that's how I know. My CEL light is in the lower right under the oil pressure gauge and the cluster I swapped in was on the upper left. The CEL was on all the time with the new cluster.

To be totally honest with you guys my CEL has remained off for at least a solid month until yesterday..........hahaha. It was once again a dreaded misfire problem, but I took my scanner back and just manually reset the computer. Has'nt come on at all today, and I've been driving all day.

I think I'm going to drop off my old 2.3 injectors to be professionally cleaned and then install them along with new plugs and wires again and go from there. Don't get me wrong, the old girls running like a champ right now and only does the misfire dance about once or twice a week now......and that's only for about 5 minutes at that tops! BUT......only at idle as well. Under load or at highway speeds she's good.

I originally solved the problem by switching coil packs and moving plug wires around. That's it! I'll keep you guys posted and if you have any questions feel free to ask as I'm now a genius on this problem.

Don't ask me how.......hahaha





Allen