For the 2nd time in 3 years I tried to take the car to Eureka Springs.  For the 2nd time, I had to take the car back to 71Shark's place.

This time I could drive it back so no wrecker driver screwing it up.

The problem is, the longer you are driving, the more it starts to miss/backfire?  You hear a pop or two out the drivers side side pipe.  Then you hear it more and more until it is bogging down the motor.

Data: speed not relevant, rpm's not relevant, under load or not - not relevant, no smoke at all.  It sounds somewhat like when you are at a higher RPM and let off, the backpressure popping you get. 

It seems to run fine and idle fine when cold, but the warmer the closer together the pops.  When at idle speed when warm, you get pops out the drivers side in a non-consistent rhythm. 

It appears that 71Sharks car may have the same problem as we put mine away and loaded up in his car, only to have it doing the same thing but his does it also when cold.

Any and all help would be appreciated.  We will have limited connectivity till Sunday, but please don't think we're ignoring you.  We made it to Eureka Springs in his Blazer.

Thanks,

may sound like fuel not combusting on one side? Spark plug broken? Spark wires burnt? Is the timing on? Heat riser stuck?..Dennis, this is one for Joel??

Sorry to here you are still having problems Dennis. Check the ignition system. possible that the coil is weak or that the distributor isn't working right. Do you have the stock system or did you upgrade?

You could have a major vacuum leak or a bad EGR valve or both.  Either could make problems like you describe.

MSD Streetfire new distributor.  New 8mm silicone w/carbonfiber core, no EGR, just put L-82 aluminum intake on due to old intake leakage.  Carb just gone thru by the supposed expert in town recommended by the vette mech here. 

Will pull plugs when we get home to see what shape they are in.  None appear to be cracked or broken and no light show under the hood prior to this issue.

I know this is awful obvious and not likely, but are you sure that new distributor was indexed correctly when it was installed?  Being off one gear can make a car run really bad.

The distributor hold down bolt may be loose and the distributor is rotating slightly.

Another possibility is what happened to a friend last year.  He installed a new MSD distributor and it turned out the shaft was just a bit too long for the engine and it ran funny.  He had to install a shim of some kind under the distributor flange and no more problem.

If BOTH of ya'll are having similar problems, I'd think the only real common issue would be FUEL quality, since ya'll live in the same area.
Only "pops" from one side is either a plug/wire, OR...a valve/valve spring problem. You could possibly have a cam taking a dump, too. I think I'd wanna do a compression check first, if you know all of the wires/plugs are good.
My 'Burban is exactly the same, which is why I quit driving it until I get time to fix. I have done all of the troubleshooting, and it is definitely a bent/burnt exhaust valve, on the drive side, no less.

[QUOTE=Adams' Apple] If BOTH of ya'll are having similar problems, I'd think the only real common issue would be FUEL quality, since ya'll live in the same area.
Only "pops" from one side is either a plug/wire, OR...a valve/valve spring problem. You could possibly have a cam taking a dump, too. I think I'd wanna do a compression check first, if you know all of the wires/plugs are good.
My 'Burban is exactly the same, which is why I quit driving it until I get time to fix. I have done all of the troubleshooting, and it is definitely a bent/burnt exhaust valve, on the drive side, no less.[/QUOTE]

Geez bro was that supposed to be a comforting thought.....

Let's hope the boys just have a tank of bad gas.... burnt / bent valve.... AaaaaaRrrrrGgggHhhhh......

I couldn't have said it better Tux!!!!!!!!!!!!