Intermittant Boost??

[gvt]

Lately when I shut the truck off for a short period of time, less than 5 minutes, there is no boost when I restart. It only does it if the engine is at operating temp when I shut it down. Boost usually resumes after a few minutes, sometimes longer. When running with no boost the truck is low on power, egt's go up, but not much additional smoke. Any ideas where to start???

[moondoggie]

Good Day!

Dust off that old vacuum gauge & check your vacuum. (At idle) ~ 20" at the vacuum pump & (of course) the inlet to the Wastegate Actuator Solenoid, ~ 3/4 of that at the outlet of the Wastegate Actuator Solenoid & over at the Wastegate Actuator. I've sometimes picked up a long piece of hose from the hardware store & then can lay the vacuum gauge on the dash to see what's going on.

Good Luck & Blessings!

[TJ Moose]

Yeah - it sounds a little like a heat soak problem, so be thinking of which "device getting older" might be getting heat sensitive. (Underhood temps would go up when rig shut down, and would take a bit to drop again after startup.) This could be the acuator, or I'd think more likely the solenoid - for places to start. But a little time with the vac gauge, both when you have no boost, and after the boost comes back will help sort it out.

[gvt]

Thanks for the replies, I've been out of town. I'll get a vacuum gauge this weekend and check it out. Where is a good place to tape into a vac line? Will I get an accurate reading if I measure at the egr (non-functioning)?? Thanks again!

[gvt]

Ooops! Guess I didn't read moondoggie's reply very carefully! Thanks