1500 3.9 Problems

[Enajizer]

Just to update on this. I ended up removing the engine from the van and found the timing chain was so wore that it was rubbing the side of the block and made a pretty deep goudge into it. As a matter of fact, when I went to remove the upper timing gear bolt, the gear was actually able to slip on the chain. Also had marks on the pistons where the valves had contacted them. I ended up putting a remanufactured longblock in and it starts every time now without a problem. Although, it is still having the chugging symptoms from time to time.

If I'd known the timing chain was the main problem in the first place, I would have probably just changed that. But with the valves hitting the pistons and things, I was better off to replace the whole engine. The van was in the shop for a while, but we were told the chain was in good shape....but apparently not.

Thanks for the replies!!

[jodos4633]

hi,
still having chugging problems--
remove fuel tank and clean it out, also change fuel filter.

[bigbaribob]

Have your checked the catallitic converter. If the converter is contaminated or broken you can get backpressure that will upset the start mixture?
Have you had the codes checked.

[keepitsimple]

This is an old thread but I thought I'd post if it'll help someone out... I had the exact same problems described by the original poster but in my 1997 Chevy Astro 4.3 V6. Tried everything like the original poster but nothing fixed it permanently until I had the fuel injectors (called the "spider" assembly) and the fuel pressure regulator replaced. Hope that helps.