02 Chevy Express 3500 5.7L

[dksob81]

I am working on an 02 Chevy Express 3500 (5.7L), my boss towed into the shop, that won't start. I replaced the fuel pump in this van about 6 months ago or so. We originally thought the fuel pump was bad again, we charged the battery and tried to start it but it will not start the fuel pump kicks on but it just like kickbacks (backfires through the intake) if that even sounds right, like the timing is off. the van has over 130k miles on it. Removed the air filter and sprayed some Starting Fluid in the air box and it started for a split second - so my boss is thinking the fuel pump, so I remove the doghouse and checked fuel pressure and I get about 65 psi, so I know thats not the problem, I still think it's a timing issue - any common problems with timing issue or any other suggestions?

Joe

[MT-2500]

Timing is not adjustable.
What is the security light doing?
Lower right side of dash cluster.
On for a bulb check and then off or staying on?
Any codes or check engine lights?
Any other repair history besides fuel pump?
Good hot blue spark to more that one cylinder?
Does the fuel pressure hold good or bled off fast?
Tank got plenty of gas in it?
Has it been acting up before?
Did it quit on the road or just fail to start?

On timing.http://files.automotiveforums.com/ga...hp?photo=51302
http://www.automotiveforums.com/vbul...d.php?t=881442

[dksob81]

Originally Posted by MT-2500

Timing is not adjustable.
What is the security light doing?
Lower right side of dash cluster.
On for a bulb check and then off or staying on?
Any codes or check engine lights?
Any other repair history besides fuel pump?
Good hot blue spark to more that one cylinder?
Does the fuel pressure hold good or bled off fast?
Tank got plenty of gas in it?
Has it been acting up before?
Did it quit on the road or just fail to start?

On timing.http://files.automotiveforums.com/ga...hp?photo=51302
http://www.automotiveforums.com/vbul...d.php?t=881442

just to answer these questions:

The security light comes on then goes off.
no codes stored
not that we have done at our shop
spark is good
fuel pressure holds for about 5 minutes (didn't chech past that)
5/8 tank of gas
no just started.
Died while driving and wouldn't restart

I got to work this morning and same thing, so I marked the distributor and then loosened the retaining bolt and turned the distributor counterclockwise a smigin and it started right up, shut it off returned it to normal and it started up again no problem. So from searching around online last night it appears the Crank Sensor is bad, I checked the distributor adjustment and it was 32 degrees advanced which is well out of range and according to the TSB # 00-06-04-014 this will happen when the crank sensor goes bad. So I set it back to 0 degrees and it runs fine - I replaced the Crank Sensor, relearned the variation of the crank sensor, and resynced the distributor (again after replacing the Crank sensor) and it is running like a champ again.

I hope this helps someone else out with this problem, I honestly thought it was a hard (as in Chain/gears) timing problem not just an ignition timing issue.

Joe

[dksob81]

Also, I did not check for codes until I got the van running. didn't think about it earlier.

[MT-2500]

Originally Posted by dksob81

just to answer these questions:

The security light comes on then goes off.
no codes stored
not that we have done at our shop
spark is good
fuel pressure holds for about 5 minutes (didn't check past that)
5/8 tank of gas
no just started.
Died while driving and wouldn't restart

I got to work this morning and same thing, so I marked the distributor and then loosened the retaining bolt and turned the distributor counterclockwise a smidgen and it started right up, shut it off returned it to normal and it started up again no problem. So from searching around online last night it appears the Crank Sensor is bad, I checked the distributor adjustment and it was 32 degrees advanced which is well out of range and according to the TSB # 00-06-04-014 this will happen when the crank sensor goes bad. So I set it back to 0 degrees and it runs fine - I replaced the Crank Sensor, relearned the variation of the crank sensor, and resynced the distributor (again after replacing the Crank sensor) and it is running like a champ again.

I hope this helps someone else out with this problem, I honestly thought it was a hard (as in Chain/gears) timing problem not just an ignition timing issue.

Joe

Good work.
Good find
That proper testing always finds the problem.
Glad you found the problem.
And thanks for posting back the fix.
A tip on fuel pump.
If that model van every comes back for the fuel pump coming and going or quiting always check the fuel pump wiring plug in at the transmission cross-member.
I have had several with bad wiring in plug in.
Had to wire around them.
Good Luck