Possible Ignition Problem?

[martinlaw]

Can anyone throw some light on the following problem?

Last week went our for a run and everything was fine, stopped to fill up with fuel and car would not start for a while, then caught but would not run properly or idle.

Did around 5 miles like this but would not clear. This has happened before but sorted itself out! This time i thought i would try to get to the bottom of it and started by taking out the plugs, interestingly plugs 1 and eight were both very sooted up and 'wet', all the others looked normal. Took the distributor cap off, it was a little damp in there but no obvious signs of a problem (the ignition leads for 1 and 8 are next to each other on the cap).

i am no expert but i think i may have an ignition problem, but on both 1 and 8 cylinders at the same time???

The engine is a AM 525bhp with MSD ignition and distributor, 750dp carb.

Any suggestions please!

Martin.

[spatz]

if this is happening right after fueling up it might be you caught some dirty fuel once.
If you settle a few days for the dirt to sit down on the bottom of the tank and the car is running fine again, it looks like you have this problem

[martinlaw]

Hi Spatz,

thanks for your response.

If it was dirty fuel the car would have still started ok as the fuel in the pipes and filter etc. would be clean until the dirty fuel reached the carb.

does not explain why plugs 1 and 8 were fouled?

[Steve_D]

Have seen in the past mention that the MSD dizzy can suffer condensation. Not had it myself.

It can sometimes be quite difficult to hear a misfire in a V8 but that would seem to be what is indicated by the plugs. Check again the cap and look very carefully for any cracks. Check the lead attachment to the cap and check for cracks on the outside. If possible swap out a lead and see if you can move the problem to another cylinder.

Happy hunting.
Steve

[V8Dom]

martin ring me before topgear

.... Dom

[crafty]

How about a bad connection on the ignition key? Next time it happens try running clean +12v direct to the MSD and see if it goes away.

I had mine out last weekend after 3 months of sitting in the garage.I'd tried to start is about a month ago and it wouldnt fire. I'd spent the month fearing all sorts of terrible things and was stoked to find out it was something as simple as a dirty fuse.

[martinlaw]

Thanks for the input everyone, hopefully your suggestions will cure the problem.

[60mph]

I had this problem with my car . Cylinders 1+8 run on the same idle screw which may be out too far. There are four but I dont know which one as cars gone . However mark your screw positions and then screw them all fully clockwise and then out by 2/3rds of a turn . Also put clean plugs in as once sooted they wont fire quickly . I also had a mist of damp in my D cap after I'd hosed off the engine . Again fouled plugs took a long time to fire . If it doesnt help set your screws back to where they were .

Frank