I'm not saying to pull the covers. If he has the return rate tool set, this should be a very easy test for him to do and should have been the 1st test he did BEFORE pulling the covers. The GM TSB I believe even states to isolate the exterior returns and check bank to bank return amounts 1st.My mechanic pulled valve covers, checked injectors, in spec really good. CP3 returned too much. Replaced with Thoroughbred Reman. Replaced fuel pressure relief valve with new Bosch. Still desired 5000, actual at crank6 500 or 600. Still crank no start. Now what should I do?
Can injectors be bad and still have in spec return rates?