Hi, just finished my first rebuild. I have a 13b turbo, 1991 so i believe its an s5. Upon dis-assembly I found that the apex's were damaged. Everything else was ok. So after the basic rebuild, (meaning i bought the basic kit gaskets, seals etc,) I stuck it back in my sandrail. It had a old Haltech e6k. I replaced it with a Sprint 500 re so that I could use my lap top to set it up. I tried all the DOS crap with the older version without any luck. Engine runs fine. I have 92 lbs compression in each rotor,+ or - 2lbs. The issue i have is each and every time my turbo reaches 0 on the guage, i guess meaning 0 vacuum to boost, the motor hesitates out, you hear the release of pressure, then the engine runs fine. I can take the motor to the limiter was long as I do it slow enough as to not build boost. No matter what speed or load is on the engine, 0 vacuum to boost equals motor not liking it. I checked for leaks, tried with out the actuator, re-built the built in waste gate (had slop in the throw arm so now its nice and tight but smooth) with no help. Turbo I had checked, it is fine. I am out of my scope of knowledge at this point. I am a beginner and had no luck finding similar troubles on a single turbo set up.

Also if i put the peddle to the floor, the fuel is cut off to engine, I back off it comes back. I'm sure that's something in the computer I need to check on.

So any other advice would be appreciated.

 

The Haltech needs to be tuned.

Don't drive under load until it has been tuned or you will end up rebuilding the engine again.