altarchsa

Thanks springer3. I'll use an old plug to generate a spark gap.

altarchsa

Last night I started to pursue some of the suggestions offered here, but I checked the distributor timing first, just to make "sure". It was right on.

I tried pulling the plug wires one at a time with no noticable change in the rough running.

I checked vacuum connections and everything seemed OK. I heard an air leak and found that the crimped clamp to the rear hose of the ISV was loose from the cleaning operation. I replaced it with a new screw-type clamp, but no change to running condition.

I began checking intake joints and noticed a change when I pushed down and forward on the right side of the intake system. I found the rubber intake connector to #5 displaced. I loosened the clamps, repositioned the connector and re-tightened the clamps.

When I restarted the engine, I was sure I would hear a smooth idling, perfectly running motor. But it actually ran worse. Different but worse. I had removed the air cleaner to get at the connector and I could hear what sounded kinda like it was backfiring through the intake, with an intermittent popping noise. Not loud, but definitely an intermittent popping.

I had my Glock with me but decided not to use it just yet.

I had 3 new intake valves and all new intake guides installed this time out. The thought of this motor having to come out of the car again for a bad or sticking valve would be more than I could take. I'll drive it off a cliff first!

My wife was rushing me to go eat dinner, so I just threw up my hands. Tonight I plan to more carefully reposition the #5 intake connector and carefully check the others, then go from there.

Does anyone know of another cause for the intermittent popping, like maybe a bad injector, that might have been the cause of the original issue, and that might give me hope of an easier to fix issue that may be a possibility, rather than a valve problem?

altarchsa

Note: Pulled the plug wires one at a time with the other system disabled.

Indycam

Who said that ?

springer3

Put the gun away! It is a machine and your hobby. It is time for a beer long before it gets frustrating.

If the engine has proper compression, fuel, and spark, it will run fine. My suggestion is to check the compression next, as all the fidgeting is for naught if compression is off on one or more cylinders.

I think you are right to be looking for vacuum leaks. I would be very worried that one of the rubber cuffs on the intake was off. That is a rigid casting/mounding, so if one is off there are probably more problems.

Indycam

You should see a difference with one out of six not firing .

altarchsa

Thanks springer. Just kidding about the gun, but this has been a really frustrating 3 years with this car and the pain to gain ratio is lopsided. I think I'm not too far from having this motor right and was planning to do a compression test next to assure that there's no problem with the valves, even though they were re-worked.

I won't be able to work on it for several days, but please stay tuned. Your and Indycam's help are very much appreciated.

altarchsa

Thanks Indy. I'll run the test again just to make sure. Your continued help is very much appreciated!