Bear with me. This might get long. 5.8 351 Windsor engine

Van began running poorly, it would miss, spit and backfire when trying to accelerate. It finally died and would not restart. Thinking the timing chain has slipped a tooth, we advanced the ignition and it started. OK, timing chain confirmed, or so we thought. Tear the engine down to the timing chain and it is fine, dots line up, but it is a little loose, so we replace it. Put it all back together and same problem. If timing is set at 10 deg. btdc, it will hardly run. Advance it to 25-30 deg. it runs but spark knock like crazy. Back it down to 10 deg btdc like the book says and it spits and sputters and finally dies. Now it will not start at all, no matter where I set the timing. It has no spark, according to my timing light. Took the distributor to parts store and they check the ignition module. It checks fine.

Any ideas? I consider myself a decent amateur mechanic but this thing has me stumped.

Thanks,
Eddie

 

Check your fuel pressure at the rail...... I've been working through the same issue and finally found the cause.

That fuel pressure test kit is the handiest diagnostic tool I ever had.... Right up there with a compression gauge and an inline spark tester IMHO.....

Good luck!

Oh, and fuel pressure at the rail with the key on and engine off should be ~35-40 PSI and might drop to 30-40 psi while running at idle (due to manifold vacuum modulating the fuel pressure regulator)

 

Thanks Dustmote. Fuel pressure was the first thing we checked. You are right. The fuel pressure gauge kit is a must have on these injected vehicles.

We did find the problem. Ignition coil. Put a new one on and it runs great now.