Running rough

[vping]

Morning all,

Thought you guys might be able to help on this one. About a week ago, I decided to change the oil and adjust the valves on my '74. Last time I did the valves was over a year ago and they were starting to get noisy. In a nutshell here is how that morning went.

Drained oil
Removed valve cover
Turned over engine by bridging wires on Passenger Fender relay (here is where my problem might stem from) to adjust all valves.
Pulled plugs and checked compression which was 1-125, 2-130, 3-125, 4-125
NGK BPR6EGP - All plugs were a nice light-ish brown gray but #3 had a mineral deposit of sorts on it. I picked it off with my nail but it was hard stuff and thick.
Replaced Valve cover then oil then filter.

Keep in mind that other than noisy valves this car runs (ran) like a top and is a rocket for a stock engine (with a PECO). Never a burp never a hiccup - starts without choking even in winter.

I run a one of Jeff's 25D's with Pertronix. One of three I had him build for me. In fact I should send him two more.

Started it up and she ran quietly.

All is well until I drive it. I can barely take off from a stop without it sounding like it is running on 3-cyls. Bogging and sputtering but then it kicks in fine. At higher speeds it runs like a top again. I checked and replaced the #3 plug and it still runs rough and I when I did I noticed that all my plugs are black and sooty like it is running really rich. Tailpipe is also sooty and it was not before. I've driven it about 100 miles this way to see if I can blow out anything that might have changed as a result of my service.

My fear is did I partially damage the Pertronix by trying to turn over the engine using the relay? Should I look elsewhere and is using the relay this way a bad idea?

Should I check the valves again?

Cheers
Vince

 

[BoneIdle]

Have you checked the carburetors yet? I had a float problem that produced the same symptoms of which you speak.

Mine would idle fine, then sort of conga down the road. At highway speeds it was relatively smooth ( i.e normal except for an occasional burp). Once I manfully ripped the carburetors off the engine, I discovered that the rear float was way out of adjustment.

Just a thought.

 

[bgbassplyr]

Check the valves again. Quiet when cold might equate to too tight when hot. Can't hurt to check. Might try getting engine hot, pull the cover and check the clearances hot while running. This will beat up the feeler gauge but if you can move it with the engine running, clearance should be good.

 

[PAUL161]

Vince, you didn't say what you set the valves at. I always set mine at .015 (static) to start and then work from there. I might be wrong, but I don't think the Pertronix electronic ignition would be damaged by bumping the starter to rotate the cam. If the engine ran good before you adjusted the valves, then unless one of them is too tight,(a strong possibility), it should run as before. Just a suggestion but, I'd reset them to .015 and run the engine again. If alls well, one was set too tight. PJ

 

[Roger]

You're unlikely to have hurt your Pertronix. They get damaged by being left with ignition on and motor not running for several minutes or longer.
It sounds like you're running rich, but you don't mention carburation. Most people can't resist doing something carbwise - you didn't touch anything?
You might re-check your clearances as suggested above, but the fact that it runs ok at higher speeds doesn't indicate you have a clearance problem.
I do find it odd that it has a noisy valve problem and you adjusted them a year ago or so. How many miles do you do between adjustments? Any idea why the gaps are opening up - I assume that's what's happening?

 

[vping]

Valves are set at .015". The engine sat for 12 years before I got to it and I did virtually nothing the the engine itself. I really got lucky with it. I decided to re-set the valves as running it for the past year or two, things may have settled in seeing is that it sat for so long unused. Who knows what kind of rust or build up was there.

I believe I found the problem though and it may be a result of starting it with the relay. There was a burned spot on the rotor and each lug of the Dist Cap. I cleaned them off and she started much nicer. I'm taking it on a test drive tomorrow to see how she does. Maybe there is some residual current traveling through that caused this. Whatever it may be, the test drive tomorrow will tell the story.

 

[vping]

Still NG. I ran it to work this morning and it sputters in first. Intermitant too. I did not check the timing after I adjusted the valves and wonder if that had an effect on my timing.

 

[Roger]

It might help if you told us how you adjusted the valves - I mean what method you use to ensure you adjusted them at the proper position.

 

[vping]

Adjusting the valves was by using the rule of nines and at .015" I'm sure this is fine.

So I decided to swap out the cap and rotor with a used set I had from a dizzy that was sitting on the shelf. Runs like a top again. Not sure what happened to the cap and rotor but all is well now. Go Figure?

Vince

 

[Roger]

Go figure indeed. Enjoy!