Recent Engine Change, P1345 Code

[Tombigbee]

1999 Tahoe, 5.7 Vortec, 250,000 miles.

Just had junkyard engine put in replacing original. Mechanic said this engine had been rebuilt recently. Yard is giving 90 day warranty, and my guy has put in many of their engines without problems.

It is running perfectly, but SES light is on, and his scan tool shows code P1345, crank/cam correlation. He used my old distributor with new cap and rotor. He did not replace the gear, saying it looked OK. He has reset it twice, but code returns after shutting down and restarting.


He claims that if the distrib was off a tooth, the engine would not run as well as it does. After that, he's not coming up with any other ideas for now.

I would really appreciate any help or advice anyone might have in curing this. The light is just annoying, but I'm worried that it might be warning of some serious problem in the future. I even read where some guy lost his engine when the gear failed, and took the oil pump gear with it while at highway speed.

Thanks in advance for any help.

 

[SunlitComet]

If your gear is fine then your distributor is out of adjustment or your crank sensor is busted. This may help but also check to see if the scan tool reports wildly rpm readings to and report back if crazy rpm readings then the crank sensor must go then:

To insure proper alignment of the distributor, perform the following:

1. With the ignition OFF, install a scan tool to the DLC.
2. Start the engine and bring to normal operating temperature. IMPORTANT: Cam Retard Offset reading will not be accurate below 1000 RPM.
3. Increase engine speed to 1000 RPM.
4. Monitor the Cam Retard Offset.
5. If the Cam Retard indicates a value of 0°+/-2°, the distributor is properly adjusted.
6. If the Cam Retard does not indicate 0°+/-2°, the distributor must be adjusted.

ADJUSTING PROCEDURE

1. With the engine OFF, slightly loosen the distributor hold down bolt. IMPORTANT: Cam Retard Offset reading will not be accurate below 1000 RPM.
2. Start the engine and raise engine speed to 1000 RPM.
3. Using a scan tool monitor Cam Retard Offset.
4. Rotate the distributor as follows:

4.1. To compensate for a negative reading, rotate the distributor in the counterclockwise direction.
4.2. To compensate for a positive reading, rotate the distributor in the clockwise direction.

5. Repeat step 4 until 0°+/-2°, is obtained.
6. Turn the ignition OFF.
7. Tighten the distributor hold-down bolt to 3 Nm (25 lb. ft.).
8. Start the engine, raise engine speed to 1000 RPM and recheck Camshaft Retard Offset.

 

[Tombigbee]

Thanks very much for that. Checked with mechanic and we agreed to reconvene to perform your suggested procedure.

He is not sure if his scanner reads cam retard offset. Would that be common on most of them, or is that function only found on the more sophisticated tools?

 

[SunlitComet]

I believe it is available in scanners with enhanced gm scanner abilities. it's value name is usually called CMP Retard or cam retard.

Post from some where on the web:

ScanXL with the GM enhancement does support “Camshaft Retard Offset”. The GM enhanced parameter in ScanXL is called “CMP offset”. The minimum product you will need is an ElmScan 5 Compact with ScanXL Standard and the GM enhanced package. I think the unit has been upgraded but it would cost$400 and is laptop/pc based.

I am sure they are not the only ones (OTC Nemisys does I think)and a dealer should be able to do it. Maybe some $$.