Hard Hard Starts

[Stratosurfer]

All,
Tahoe cranking longer than usual when warm. Cranking when cold as normal. Throwing following codes: P0236 P0101 P1409. Similar issue a couple of years back when The General put a new IP on under warranty. Mech said IP 'lost' it's timing and before I could get the truck in it had 'recovered' it's timing by itself and even cleared the CE light. Is this a connector issue? Vacuum turbo wastegate feedback issue?
Any help appreciated.

[Robyn]

Hi there.

Check all battery connections/cables and make sure you have a good solid 14V to the chassis supply.

A bad ground or poor ++ voltage can cause issues.

The MAF code is likely not related to the other two codes.

Be sure the vacuum pump, lines and such are working properly.
Pump should be able to provide a steady 26"hg as measured at the pump.
The needle on the gauge needs to show a steady reading. Wiggling wobbling readings indicate a bad vacuum pump.

Starting is not effected by any of these codes.

Where is the PMD and is it new??? Is it an old style Stanadyne unit.

If the PMD is an older style (Black) Stanadyne unit, it is suspect.

If the PMD is still on the IP where the GM dealer installed it with the new pump then there is even more reason to suspect it.

DTECH PMD remote mounted in a cool spot.

As I mentioned, the codes are likely not related to the hot start issue.

Other things to check include the fuel filter. (If its has got more than 3 months on it, change it)

Fuel shut off solenoid (up top of the IP) These can have issues when hot. If the coil gets weak the thing may not open when the key is turned on.

Lift pump issues. Be sure the lift pump is working especially when the rig is hot.

This will give you some things to check.

Keep us posted


Missy

[Stratosurfer]

Robyn,
PMD is DTech remote mounted, Don't think this is the issue, will check the rest.
Thanks

[ronale]

I had same problem with hard cranking. Replaced all injectors (100K miles) and no more hard starts. My theory was that injectors were leaking. Pressure in injector lines had to be rebuilt by more cranking than usual.