tuirbo wastegate not operating

[yamakev]

having trouble.94 gmc 3500hd dtc 78,i found i had no vacuum and rplaced bad pump and lines.i hav 22" of vacuum at new solenoid.only have 6 volts there at idle.solenoid wont open now what.help!!!

[Robyn]

Welcome to TDP :D

Be sure all the electrical connections are good as well as all the grounds on the engine (RH rear or in take coming from the main harness)

Be sure your battery connections are good and you have 14V to the main supply lug to the system

Now you have 22" at the solenoid OK

What do you show at the wastegate actuator on the Turbo??

At Idle this should be about the same (22"hg)

If you have zero at the actuator then there is likely an electrical issue.

Let us know what the vacuum is at the actuator.

The voltage varies depending on what the ECM sees for boost and then it applies a pulsed voltage to control the wastegate by allowing it to open and allow gases to bypass the turbine.

Let us know

Robyn

[syon99]

If you need to use the truck ASAP then I suggest ordering a Turbo-Master from Kennedydiesel.com. This low cost mechanical device will get your 1994 style wastegate moving while you address the more difficult issues.

[yamakev]

i have 0" at wastegate actuator.i put a pump on line to actuator and it held 22".cant seem to get solenoid to work.still only 6 volts,grounds and connections seem ok.