Your Friday night Troubleshooting video

[popscomet]

In these old fords run a autolite bf42 or whats it's equal and don't buy into all the hype on these new fang-dangled spark plugs,thats what is in my 289 and they have been it for so long I honestly can;t member when they have been changed,and anyone that was at PF can tell you it started right off the bat and I'd reach over from the passenger side and bump the key and it would just bust off and thats with 2x4 carbs on it and I would never touch the gas,and it idled and did just perfect and it did it every time...........pop

[Groover]

Groover was the bad plug in there before you changed over to the pertronix ignition??

Too long ago to remember The Pertronix dizzy has been running for two years, and I don't recall pulling a plug out since to check. I am pretty sure that the vacuum advance on the dizzy is not working (might have something to do with my poor gas mileage).

I've changed the plugs, the cap and the rotor so except for the plug wire, you would think that nothing left electrical could be isolated to just the number one cylinder (I don't know exactly how the pertronix works, but it doesn't seem it could be that isolated in a failure).

I do have a standard dizzy around here with points, so I could swap back and see. But I'm gonna run this way for a bit, then I'll pull the plug again and see if it looks as bad.

With 150 psi on each cylinder, can I rule out any catastrophic leak (head gasket, or bad rings, etc)?

[loman]

I agree with Roy, and trying to find out about the fouled plug before playing with the power valve. If you are going to run it a while again without putting new plug wires on I would think about swapping the plug wire from #1 and another cylinder. Since you changed the plugs and cap, moving the wire hopefully could isolate the problem to cylinder 1 or the problem would go to a different cylinder where you moved the wire. If the problem is still at #1 you may have to tear into the motor more to find the source.

[CALIFORNIA CALIENTE]

loman nailed it!The ONLY thing you have not changed is the plug wire,move it to another plug and see what happens.Cranking pressure can fool you,the engine is NOT at full temperature,not at rpm,coolant and oil are not up to temp,engine and corresponding parts are not hot and have not stabilized!Something had to cause that fouling,find the reason/reasons for it,same thing goes for John,there has to be one cylinder not happy,an ignition issue should effect ALL the cylinders,,not just one!! JMO , ROY.

[poboyjo65]

loman nailed it!The ONLY thing you have not changed is the plug wire,move it to another plug and see what happens.Cranking pressure can fool you,the engine is NOT at full temperature,not at rpm,coolant and oil are not up to temp,engine and corresponding parts are not hot and have not stabilized!Something had to cause that fouling,find the reason/reasons for it,same thing goes for John,there has to be one cylinder not happy,an ignition issue should effect ALL the cylinders,,not just one!! JMO , ROY.

Roy I guess mine was a rare incident. 5 of the plugs looked good like my second pic, but 3 of them weren't getting fire ,,,or at least not good fire . it barely made it home ,would barely run. lucky I faced no hills because it wouldn't pull. This was about 3 years ago or more so I cant remember which plugs it was but I do remember the plug in bottom pic was next to the bad one. If memory serves me correct after I checked these plugs I checked fire at the bad plug & it was poor or none & then I looked in the dist & saw a strand of copper wire that had sprayed out. it was from the pickup coil. After I changed the pick up coil & it ran fine. It was a head scratcher!

[poboyjo65]

Groover where on the motor is your gauge hooked up? Is it possible the gauge is picking up the movement of the pcv ? If you have it close to it or on the same line you might move it elsewhere just to rule that out. reason I thought of it -I was blowing my pcv out with the airhose & it was fluttering,fluctuating,rattling with low pressure & pointing up,I can see the core is bouncing up & down . you might even remove it to test vac if the hose will stay in with out it.

[Groover]

Groover where on the motor is your gauge hooked up? Is it possible the gauge is picking up the movement of the pcv ? If you have it close to it or on the same line you might move it elsewhere just to rule that out. reason I thought of it -I was blowing my pcv out with the airhose & it was fluttering,fluctuating,rattling with low pressure & pointing up,I can see the core is bouncing up & down . you might even remove it to test vac if the hose will stay in with out it.

Been thinking about that. It's on the brake booster right now. PCV is direct from manifold, but that is something that might bounce like this. On the weekend, I'll try to disconnect the PCV and put the gauge directly on the manifold (removing the brake and the transmission). Then if it still bounces that would move me toward the carb. Could be the throttle shaft, but I'd think it'd be more uniform in the leak.

As for the plug. I'll pull it this weekend and see what it looks like. If it's clean then maybe that fouled plug was just a fluke? If it's fouled then I'll replace it and swap the plug wires to see if that wire is bad.

[poboyjo65]

Groover did you ever solve this mystery?

[Groover]

Pulled the number one plug after two weeks of driving, and it is not fouled at all like before. There is, however, oil on the threads (as there was before)? I saw in Poboy's post on someone else's thread that this may be a sign of oil leaking from the front of the head?

At any rate, the vacuum is still bouncy under load. Next time I get some time, i'm going to try to isolate the vacuum gauge and remove as much other vacuum as I can to see what happens (PCV, Brakes, Trans).

Also today, I confirmed that the vacuum advance was definitely not working at all. So I changed that and now that is working. Then I noticed while checking the timing that at higher rpm (3,000) the light started to miss a few times every couple of seconds. Could be the light, but as we all noted, plug wires are the only thing I didn't replace. So I'm going to replace those this week.

Hoping the vacuum advance helps with the gas mileage.

Car still running fine, so whatever it is, it doesn't seem to be catastrophic.

[poboyjo65]

I noticed oil on the threads of some of my plugs when my intake gaskets were sucking oil from the valleys & leaking v covers > I suspected oil being on the threads was because the cylinders were getting so much oil in them. I could see oil around the base of the plugs too, like it was keeping it burned off the center of the electrodes. it kept getting worse, missing, not running right, finally started oil fouling a plug & another was pretty bad oily but tan tipped. make sure the oil isn't getting on the plug from the outside.