Fouling one plug ???

[JPN800]

after i finally got this new engine install sorted out, I am having a problem with #5 spark plug fouling. The car has a steady hessitation when i accelerate. Could the coil pack or ignition module have gone bad just by sitting around? Plugs are FR1LS ( M&A heads) gapped at .30 and everything else checks out O.K. All the other plugs are a light golden brown color.

 

[Ormand]

Seems to me that if it were coil pack or ignition module, it would foul TWO plugs, not one.

 

[bison]

Seems to me that if it were coil pack or ignition module, it would foul TWO plugs, not one.

Agreed. Check your wires. It could also be an injector problem(leaking or sticking open). Make sure the injector harness isnt shorted to ground. If those all fail, do a compression test.

 

[JPN800]

my fuel rail holds pressure for a lond time so i dont think its a leaking injector. compression test was done and it was ok also, i will have to look into the harness. i did try to un plug each injector one at a time to see any change in the way the car ran but they all seemed to affect it equaly.

 

[Jerryl]

Funny, just posted on this issue. (That is the funyy part)

I would say, verify the ECM.

My first reman ECM failure took 3 weeks to figure out. It dropped cyl no 6 (plug was wet) Replaced injector wiring, plug wires, plugs. module, coil, injector, traced wires, etc etc. (If you ever worked on a Hot Air, you would appreciate the work to change the injector)

Second reman unit went out with all the codes displayed.
Third unit lasted 20 miles, dropped another cylinder.
My current unit from RedRegalT is still running 1800 miles later. (Yes, I have a spare now :tongue: )

 

[JPN800]

My car has a DFI so its not like i can just swap in a different ECM. keep the ideas comming...

 

[Jerryl]

My car has a DFI so its not like i can just swap in a different ECM. keep the ideas comming...

Guess I should not "ass-u-me"
Everytime I do, I am wrong on these cars.
TT 4 ya.

 

[dhjenkins]

Replace the fouled plug with a new one (don't just clean it) and trade wires with a non-companion cylinder. If the problem remains, trade injectors (or scope the installed one).

 

[JPN800]

Replace the fouled plug with a new one (don't just clean it) and trade wires with a non-companion cylinder. If the problem remains, trade injectors (or scope the installed one).

I cleaned it and swaped it to #3 cyl. I will try to drive the car tonight, Then pull the plugs and see whats up. i also ordered a set of new wires just incase thats a issue too. ( new msd 8.5 on ebay $40 ) i will also try a new plug if it doesnt work.

 

[Dreamcar86]

I cleaned it and swaped it to #3 cyl. I will try to drive the car tonight, Then pull the plugs and see whats up. i also ordered a set of new wires just incase thats a issue too. ( new msd 8.5 on ebay $40 ) i will also try a new plug if it doesnt work.

Contact Red Armstrong for plug wires. They are cheap and they fit perfect. Just FYI. If I remember correctly they are $26.00.

 

[JPN800]

It runs awsome.... It must have fouled when the wires were crossed and never cleared up when i corrected the firing order. now that they are all clean it runs great. im glad i didnt waste all that money on a new coil pack and ignition module.