Well blew a rebuilt motor after a boost spike. Blew out the rear rotor. DId a compression check. THe front checked good but the rear was gone. So I opted only to tear half the engine apart and rebuild the rear only with new housing, rotor, and seals.

Now engine is back together and assembled in vehicle. Starts back up and idles only when cold but only 10lbs of vaccum? Did a compression check and i get 6 even bumps. Now wondering why engine is low vaccum. But this is on a piston compression tester so

I thought maybe the injector clips were bad since the were broken. So I took off the UIM and redid all the injector clips and redid the injector ground even ran a wire to the negative of the battery just to make sure. Engine still has same issue. WTF? Bad primaries maybe?

Everything is the same as it used to be on the motor before it blew? Did I **** up by not inspecting the front .

Can anyone chime in before i rip this motor out again.

 

also it hits the wall at around 4k if you try to drive it under partial throttle with a 2-3lbs of boost. Never had this issue on previous motor even when it was blown.

 

Not wanting to go past 4k would also be due to running extremely rich. Is your air flow meter connected? You said you did a compression check, where are the numbers? Is there any code it is throwing out that might help you find a disconnected sensor? Also check the timing with a timing light.

 

I havnt checked with a timing light yet because the engine is unable to idle. yes afm is connected.

I did the compression check with throttle closed so I only got around 80 psi per face of the rotor.

 

Check for vacuum leaks with a can of "engine starting fluid".. Spray it around the engine bay and listen for a tone change.

 

Hey man dunno if you have fixed the problem yet. But I have run into the wall to at 4k before I tried everything everyone suggested. Turned out to be the fuel injector resistor pack located under the air intake right front fender well. Secondary resistors had sorted out check it out you never know.