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Cylinder 1 misfire?

Kejtar

Kejtar

PostMaster General
NAXJA Member
Location
Westminster, SoCal
That's what I get for driving the jeep..... so yesterday I decided to dust off the heep and take it to the M&G. On it's way out of the driveway check engine light came on, I grabbed my code reader and it came up with cylinder 1 misfire detected... well fine.. I reset the code, reseated the plug wire and all was good. When I got to the M&G (10 minutes later give or take) same code came up again. Figuring it's a bad spark plug wire I swapped it with a spare and it seemed to run fine till on the way back home it came up again.

Figuring enough is enough I picked up new wires and new cap and rotor (those were fairly old while plugs have probably less then 10K on them: champion truck plugs).

Popped the cap and rottor off today to find that my distributor is WAY wobbly. Ok, back to Kragen, got a new distributor, popped that in, reassembled everything with new cap rotor and wires and guess what comes up again....... yup, you guessed it: Cylinder 1 misfire.

Ok, it could be ..... plug or could it be a bad injector? What should be my next step in trying to figure it out?

97 4.0 AX15.

Thanks
 
A cylinder misfire code could mean that you don't have compression--carbon build up on a valve holding it open so no compression is built. A cylinder misfire code could mean that you have a galled valve guide causing a valve to intermittently not close completely, again no compression. A cylinder misfire could be the result of a bad injector.

However, do as you will, and good luck to you.
 
Ok, I just played musical chairs with the plugs and the problems stayed with cylinder #1. I also hooked up an inline gismo that lets me monitor the spark and cyliner #1 is getting a nice solid spark.

Trying to decide which route do I go next: I have spare injectors that I pulled from my rolled jeep that I can try. Btw, I pulled the injector wire and got a different code:201 (to confirm it's not connectivity issue on the injector). Any way to test an injector short of pulling it out? And then when I pull it any way to test it?
 
Just pull the connector off the injector. In fact, stick a NOID light on the connector and see if the number one injector is getting a firing impulse.

Good luck.
 
joe_peters said:
Just pull the connector off the injector. In fact, stick a NOID light on the connector and see if the number one injector is getting a firing impulse.

Good luck.
Click to expand...

Hmmm don't have a noid light... Getting back to pulling the connector: as I said I did... and I got 201 which means open injector error or something like that.
 
Ok, misunderstood your post, thought you removed the injector.

Well, swap 1 and 6 injectors and see if the misfire moves.

Good luck.
 
You could grab a kitchen spray bottle an "mist" the wires to see if somewhere its going to ground instead of firing the plug.
 
Any update on this im having the same problem my 97 is throwing the same codes misfire and injector problem? i did plugs, wire's thinking it was that but noooooo
 
Well... here's the mystery:
Cylinder 1: about 145
Cylinder 2: about 140

Vacuum does not seem to fluctuate (though it's a cheap vacuum gauge)....

WTF?
 
Ok, lets recap:

Compression in No. 1 is good and in No. 2 also.

Moved the spark plug around--still misfiring.

BTW, do you notice the misfiring or is it just throwing a code?

Vacuum is good--high and steady, indicates no carbon on the valves or sticking valve guides, no broken or collapsed valve springs--all kinds of good info there except I would expect a blip on the gauge when No. 1 misfires.

Ok, did you move the No. 1 injector yet? If not, give that a try and post up.

Good luck.
 
joe_peters said:
Ok, lets recap:

Compression in No. 1 is good and in No. 2 also.
Click to expand...
yup
Moved the spark plug around--still misfiring.
Click to expand...
yup
BTW, do you notice the misfiring or is it just throwing a code?
Click to expand...
It runs rough: you can feel a shudder
Vacuum is good--high and steady, indicates no carbon on the valves or sticking valve guides, no broken or collapsed valve springs--all kinds of good info there except I would expect a blip on the gauge when No. 1 misfires.
Click to expand...
It's possible that the vacuum gauge I picked up from Kragen is not sensitive enough... I"ll be trying again over the weekend but for now I"m assuming that the vacuum is steady.
Ok, did you move the No. 1 injector yet? If not, give that a try and post up.
Click to expand...
Yes: I moved the injectors around and I moved the injector wires around as well.
Good luck.
Click to expand...
Wish my engine good luck... it's very close to being taken out back and being shot.....
 
You can feel a shudder, huh? Does it get worse when you unplug the #1 injector or plug wire? If it gets noticeably worse with #1 disconnected than it ever is with everything hooked up it could be a crank sensor issue. Misfire codes are generated by the pcm, of course, with input from the ckp. The ckp goes through a profile learning process to determine normal operation then flags a code if it notices irregularities as a weak hole passes through. Perhaps disconnect both battery cables and short them to each other for a minute to clear the keep alive memory and send it back into ckp-learn mode.

Now if the miss does NOT change with the cylinder disabled then it definitely is an issue with that hole be it internal, fuel or spark. If it DOES change then it may be a basic rough running situation caused by ignition, mixture or something similar.

There's no mistaking a dead miss.
 
JJacobs said:
You can feel a shudder, huh? Does it get worse when you unplug the #1 injector or plug wire? If it gets noticeably worse with #1 disconnected than it ever is with everything hooked up it could be a crank sensor issue. Misfire codes are generated by the pcm, of course, with input from the ckp. The ckp goes through a profile learning process to determine normal operation then flags a code if it notices irregularities as a weak hole passes through. Perhaps disconnect both battery cables and short them to each other for a minute to clear the keep alive memory and send it back into ckp-learn mode.

Now if the miss does NOT change with the cylinder disabled then it definitely is an issue with that hole be it internal, fuel or spark.
Click to expand...

I have to say that it feels the same way with the plug going to 1 as it does without the wire on plug 1 which again points to the cylinder.... I"ll try shortening the cables to reset the PCM as it is possible that by now I'm overly sensitive to everything....
 
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