strange problem, need help

[Dono]

the ac thing is normal.

wtf is causing the intermittent plug firing signal?

the plugs fire in pairs, so you have 3 wires to check (and ground). how do you check these? a scope would be a fantastic thing right now.

crank position sensor on its way out? thats what signals the pcm to forward the signal to the coil, correct? theres the wiring in between, but........what else could be causing a plug to not fire?

 

[Dono]

What would a full diagnostic cost at the dealer? having the diagnostic unit hooked up to plug wires, and sensors would help you along for sure.

 

[AuroraZero]

http://www.explorerforum.com/forums/showthread.php?t=263750

Have you seen this thread man?

I know the idle will change some but how bad is it?

 

[NintendoKD]

the ac thing is normal.

wtf is causing the intermittent plug firing signal?

the plugs fire in pairs, so you have 3 wires to check (and ground). how do you check these? a scope would be a fantastic thing right now.

crank position sensor on its way out? thats what signals the pcm to forward the signal to the coil, correct? theres the wiring in between, but........what else could be causing a plug to not fire?

I have a multimeter. I have also run a full diagnostic, with the solus, a snap on plug in computer diagnostic tool like 40 grand or something. I ran it at the local shop on base, I know the guy. I can use equipment, no problem, but diagnostics just aren't their thing, they are clueless. I have been chasing this problem for only since I swapped the o2's back around. At higher rpm's the plugs fire normal, which is consistent with an overfuelling problem, the spark gets quenched by too much fuel every once in a while, then the energy left in the coil catches up and it speeds up. "you can see evidence of this in the video" Or am I wrong about this?

 

[NintendoKD]

http://www.explorerforum.com/forums/showthread.php?t=263750

Have you seen this thread man?

I know the idle will change some but how bad is it?

I'm gonna enlist the help of the wife, and check this right now. Hold on tight. Thanks everyone

 

[NintendoKD]

throttle modulation is difficult, it won't hold at 2k, but numbers were good, consistent with the test, the voltage transitioned smoothly throughout the rpm range. I need to know how to pull the center console out so that I can get to the transmission access panel, and troubleshoot the wire loom.

 

[joe doe]

do you have a full size console right up to the dash?

well anyway ,refer to this thread

http://www.explorerforum.com/forums/showthread.php?t=209770&highlight=console+removal

 

[NintendoKD]

not sure what you mean. I removed the cd thingy from the inside of the CC and the lid, as well as the HVAC controls and the radio from the dash "troubleshooting a constant 12v issue on my radio" I have the cupholders removed and the other little storage thingy as well I basically have the rear HVAC controls, cupholders and long thing that goes all the way to the lower dashboard, is that what you meant?

 

[NintendoKD]

WOW, thanks for the link, where on earth did you find that??? I was just looking for it, found my own post, and found your link LOL: I am now removing the center console. I want to have a look at that wiring harness. any schematics for this next part would be tremendously helpful.

 

[NintendoKD]

I have said it before, and I'll say it again, TURDLE be da MAN!, mountaineergreen ..... well hes is def. up there.

 

[lounge lizard]

as the compressor cycles on and off it will make the rpm roll up and down.

 

[NintendoKD]

compressor stays on, but the rpms stay at 1000 then dip, for a given time, then do it again, it is pretty consistent, however, this only happens at idle.

 

[AuroraZero]

WOW, thanks for the link, where on earth did you find that??? I was just looking for it, found my own post, and found your link LOL: I am now removing the center console. I want to have a look at that wiring harness. any schematics for this next part would be tremendously helpful.

This one?

Someone let me know if I was not supposed to post this. I will remove it immediately if it wasn't supposed to be posted.

 

[NintendoKD]

This one?

Someone let me know if I was not supposed to post this. I will remove it immediately if it wasn't supposed to be posted.

just got finished with supper, thanks for the diagram, this is exactly what I needed.

 

[Dono]

Im still stuck on the timing light showing a plug is firing intermittently. I guess I dont quite understand.

 

[AuroraZero]

Im still stuck on the timing light showing a plug is firing intermittently. I guess I dont quite understand.

Been throwing me for a loop since he showed it to me. I have heard it run on the phone even and I can't hear it do it.

 

[NintendoKD]

ok, so I got the panel off, found like another $5.00 in change, but I cannot get the wire loom to come out far enough to see, or work with, looks like I may have to drop the tranny, and pull the front tires at the shop tomorrow.

 

[NintendoKD]

does it at idle, very noticeable, when I accelerate, then the engine returns to idle, it can be heard in the exhaust note, very noticeable. like I said before, it sounds like I have a wicked cammed out v-8 under the hood. Not quite like it's going to die, but I am often asked if I am running a 302 with a cam. All of the plugs do the same thing the same way, all of the time, I borrowed a second light to confirm this. I also need to check the timing, apparently there is a way to adjust this? bad pcm?

 

[AuroraZero]

The ignition timing can be adjusted by hooking it up to a computer. Too bad you did not have another PCM to test this with. To see if yours is bad or not.

 

[NintendoKD]

mitchells

ok, so mitchells says to:

"Start engine and operate at 2000 rpm for one minute. Turn ignition off. Perform KOEO self-test. If DTC p0135, is present, go to next step. If specified DTC's are not present, fault is intermittent. Go to Ciruit Test Z."

First off, I have no idea what circuit test z is, next the engine will not stay at 2000 at all, I get it close and it jumps to 2500, i let off "big toe control" and it drops to 1100. Seriously, this thing will not stay at 2000. No DTC's, not even p0135, which happens if I drive and then stop, but only happened twice so far. Still pops and poops at around 2500 though, if the rpms go up more,less misfires, and the higher it goes, the better she runs. I wonder if it is because she can breathe better now that the flowmaster is on there? Don't judge me, it was cheaper than the one from the book for my sploder, and he had it in stock I paid 1k just for the damned cats out the door, so realistically it seemed like a heckuvah deal. It has to be the o2, or the circuit, If I can just probe the lines I can figure out what is up. I need to test from the connector to the PCM, on the signal line, test for good ground, and make sure 12v+ is going in for the heater and the sensor.