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Speedrcr
11-08-2016, 05:25 AM
My son has a 1993 Z28 - we just installed our rebuilt motor. Stock pistons, but added a cc 305 cam, 1.6 rockers, long tubes, new cat convertors, 3" exhaust and a 52mm tb. I added 4 wire o2's to it as well. I had a set of the 30# Bosch 280155831 injectors and threw those on since the old injectors were toast.
Very hard to start - long cranking, coughing, spitting, etc .... you can smell gas - it will eventually start once you hold the pedal to the floor and kill the injectors. It idles pretty decent once it clears out after starting, but it is definitely running rich. When we tested the fuel pressure it was around 42 - 44 lbs (not the best gauge) and I tested the FPR with a vacuum pump and it held for over 5 minutes without moving. It has not thrown any codes.

We are running the stock computer and just getting it running so we can data log it and then getting a chip burnt - is this normal of having the larger injectors on the car with only running the stock tune?
I was thinking of using the stock injectors to get it going and data log it, but it seems like that would defeat the purpose of going to a more efficient injector.

Sahara54
11-08-2016, 06:30 AM
If your running the 30# on stock tune, that's the reason its running so rich. The computer is opening an closing the injectors based on stock flow rates, and you will wash the rings out if your not careful. Ask me how I know...

Speedrcr
11-08-2016, 08:11 AM
Ok - that is almost what I was thinking. I have to get a good run on it so I can data log it, but maybe I'll throw in the old stock ones for a while before I get the new chip.
Thanks for the feedback

MoeHorsePower
11-08-2016, 08:58 AM
I would not even datalog it with those injectors, for one as said you will get ring wash, and your air fuel being so rich is going to throw everything off, Dont run it until you put the stock injectors back in..

agenthol302
11-08-2016, 03:24 PM
X3 on injectors I did the same thing on my 96 and put stock back in and it ran just right