Timing issue, will not run.

'96 K2500 with the 7.4, 130k miles. The Burb died on the hiway while towing my racecar. I tried to restart the the timing was way off. I've replaced the crank position sensor and the starter. The cap and rotor were replaced 7 months ago. It started up and ran for about 30 seconds, but it was extremely rough. After ut died, it will not restart. Fuel and spark are good, but timing us still an issue. Does the cps need to be relearned? What else can I try?

How do you know timing is an issue?

While trying to start it you can tell the ignition is firing very early on the compression stroke. That is why I had to replace the starter. It was also backfiring and stackfiring. When it did run last night it was extremely rough.

I forgot to mention that it has a P1345 code.

If you can line up the crank pulley to TDC and then check to see where the rotor is pointing on the distributor.

Didn't these have issues with the distributor gear wearing out or breaking the roll pin?

While trying to start it you can tell the ignition is firing very early on the compression stroke. That is why I had to replace the starter. It was also backfiring and stackfiring. When it did run last night it was extremely rough.

I forgot to mention that it has a P1345 code.

Code 1345 is the camshaft shaft retard setting is off.

Timing is not adjustable on it.
Camshaft retard setting.
Needs to be set on a engine capable scanner as close to - or + 0 degrees as you can get it.

Flat top dist?
When cap is off.
http://files.automotiveforums.com/gallery/showphoto.php?photo=51302

Also take a look inside cap for cracks or burn threw.

P1345 means the the CKP (crank sensor) & CMP (cam sensor) are not in time.

As MT said it needs to be checked with an engine capable scan tool to set base timing (cam offset or cam retard mode). 0 +/- 2 degs @ greater than 1000 rpm. This is done by adjusting the dist.

And, yes, to your ? about changing the CKP. The crank variation relearn needs to be done. Again with a scan tool that can access that function.

A couple of other thoughts. One's not bad and the other's not good.

1. Maybe the dist hold down bolt got loose and the dist turned?
2. Maybe the timing chain slipped a tooth or two, which would mess up the valve and ign timing?

Good luck to you.

While trying to start it you can tell the ignition is firing very early on the compression stroke. That is why I had to replace the starter. It was also backfiring and stackfiring. When it did run last night it was extremely rough.

I forgot to mention that it has a P1345 code.


timing chain is most likely shot..

A little more data on my problem. I put a timing light on the engine while cranking and #1 is dead on the crank white stripe (TDC).

I cleared the codes and I am no longer getting a code while cranking. Still will not start.

How hard is it to change the timing chain and gears?

A little more data on my problem. I put a timing light on the engine while cranking and #1 is dead on the crank white stripe (TDC).

I cleared the codes and I am no longer getting a code while cranking. Still will not start.

How hard is it to change the timing chain and gears?

Did you follow MT's link (above) for initial dist setting? This is crucial. Although his link describes a 6 cyl motor it also shows where the rotor should point to on an 8 cyl motor.

Your description of using the timing light might be a clue, but I doubt it as the PCM is controlling spark while cranking.

As far as your ? about changing the the timing chain & gears, it isn't easy. In other words it's a major job with the engine in.

So, go back and read each and every reply to your post. These cars today require very specific instructions to get them right.

Good luck to you.