new plugs now a stumble

[jastutte]

Yes, I know this sounds like a newbie problem. But here goes anyway. Changed the plugs today in the 96 disco. I disconnected the intake hose and took off the MAF. The MAF plug is broken and came unplugged. When I put everything back together I plugged the MAF plug back into it's socket. Before I put the intake hose back on I sprayed some intake cleaner into the intake while my wife fired up the beast. She of course sputtered and died and then restarted. The truck, not my wife. anyway, after everything was buttoned back up I tried to restart the thing and she just turned over and died. Did this several times until she finally started. Idled high and when I took her out for a drive she stumbled every time I started from a stop. She would stumble and then drive just fine. Finally realized that I had plugged the MAF plug upside down. Changed this and the high idle went away. However, I am still having the stumble or hesitation off the line.
Is this just the ECU trying to relearn after my F'up? The plugs are gapped at .04". The owner's manual calls for .032"-.038". Am I too far out and creating an issue that is easily fixed?

Sorry for the long post and dumb questions. Feeling kinda stupid. Didn't realize I could screw up even a plug change.

Anyway, Thanks,

Oh, yeah. Put in champions rn11yc4.

 

[greg409]

I don't really know if/how much .040 will affect your engine at this point.

The old rule of thumb is to go on the tight side since as the electrodes burn away, the gap will fall into range.

Ironically, I believe the issue is most noticeable at idle, tho'

I think if your MAF or ECU wre screwed up, it wouldn't run well above idle.
The maf comes into play at 550rpm - if it's bad the engine will die at 550 (try to start)


luck,greg

 

[jastutte]

she'll start but I have to feather the gas pedal. didn't need to do that before. then there is still the hesitation off the stop. looked at the can of spray cleaner i had used and it is carb and choke cleaner. hope i didn't screw up the 02 sensors. but this doesn't seem like an 02 issue.

 

[greg409]

I encourage you to go back & do it again, with MAF cleaner or "no residue" electronic cleaner.

Just take it off and soak the crap out of it. - (Don't do it hot - the cold spray might crack the hotwire)

I wouldn't trust anything else, I've done (3) of mine, (1)'s a spare, they all work great.



luck,greg

 

[wolf]

also make certain you are getting good contact with the MAF connection.

Any codes yet?

Wolf

 

[Disco Mike]

If the MAF wasn't acting up before then leave it alone, cleaning them can sometimes cause more problems then leaving them alone.
What brand of plugs, what about your wires, when were they last cleaned and as already mentioned, what about fault codes?

 

[jastutte]

no codes. MAF was working fine before. I have cleaned anyway. Contact feels and looks good. The plugs are champion 322 or rn11yc4. same plug different #. wires are magnacor 8mm. have 18,000 miles on them. did not have these issues before I changed the plugs. I'm going to pull them and adjust the gap to withing spec. and see what happens.

Talked to my wife and she said it died at start today and is still occasionally hesitating off the line.

Thanks for all the responses.

 

[jastutte]

Ok. Pulled the plugs today and regapped them from .04" to.035". This didn't change the starting in issue. Still dies the first time I start it and then the second time will start if I play with the gas pedal. One note of interest, while my original plugs were a nice tannish color the ones I pulled today and regapped were white on the tip and had some black slightly oily residue around the bottom edge of the plug. The hesitating issue seems to have lessened. Strangely, the truck only hesitates off the line from a complete stop. Never hesitates when I am already moving and punch the accelerator. Am I running rich? This reminds me of what my old fuel injected vw aircooled bus would do when it was running rich. What could I have done that would cause the truck to suddenly run rich?

I took a look around the engine compartment and everything seems to be in order. I can't find any unplugged sensors or anything obvious. I'm wondering if I damaged the MAF somehow when I had the sensor plug in upside down.

I guess my next step is to change back over to the original plugs and see if the problem persists. Anybody have any ideas?

 

[joey]

Unplug the battery overnight and let the ECU relearn things... the MAF plug may have caused a few odd errors.

 

[antichrist]

What plugs did you use? If platinum plugs a lot of people report problems and crappy running with those in D1's.
YMMV