Taking all of your symptoms into account, a timing chain issue is most likely the cause.

 

Ouch, that will hurt the wallet.

 

About $80 for the parts, if he can do it himself.

 

Alloro, I was rereading the threads here and I am curious about if the timing chain would cause the symptoms to come and go? He said that it will run fine and then act up when it wants to.

That price is very reasonable. I hope he is able to do it himself, if indeed the chain is causing the problem.

 

Yes it can. Different factors can effect whether not the symptoms are present. If the timing chain/gears are worn just enough to cause problems, then things like oil pressure, engine temperature, RPMs, engine load, outside air temperature, can keep the engine on one side of the coin or the other. Eventually the wear will be enough that the symptoms will always be there.

The reason for a backfire is because a spark plug fired with a valve still opened. This indicates the valve timing, ignition timing, and crankshaft positions are no longer synchronized. Spark timing is controlled by the crankshaft position sensor, while fuel injector timing is controlled by the pickup coil in the distributor. The distributor is gear driven off the camshaft so the injectors are firing at the appropriate time in relation to valve timing. However, the valve timing is running late due to the worn timing chain, yet the ignition is firing based on crank position, which is not late. Hence you get a spark just before the valve fully closes.

 

The chain was replaced about 7 months ago when I have the engine rebuilt.
But I will look at it again im sure I can replace it myself how hard can it be. okay after a couple of days of changing the catalytic converter the D doesn’t sound the same before I would start it and it would sound great when turning it on like if I had a supped up motor now it sounds really weak sounds like if the exhaust was clogged up. Can the CAT be gone again? The CAT seems to be way cooler than the rest of the exhaust. I have a flow master exhaust so I don’t see why it sounds like that. The D has no power I floor it and the supercharger sounds like its working too hard but the D doesn’t run. It keeps stalling sometimes it stall right after I start it. I haven’t had the check engine light come back up so im happy with that.

 

Alloro, thank you for the explaination.

 

What was the fix?

 

Well as for the timing chain that was fine, i had the cat checked out again and found out it was a burnt up from the inside, i had them put a straight pipe so know the D sounds mean, its running like a champ, i put some regular champion plugs, replaced the wires, and replaced the LDP no more check engine light so im happy, Only problem now is that when im at idle the rpm drops. i was unable to find why the D was stalling as that completly stopped

 

The stalling was due to the burnt up cat which was backing up the exhaust into the engine.