I have purchased on E-Bay what was supposed to be Fast 36lb injectors, but now since I have a custom chip programmed the car runs terrible. The injectors are light tan in color, and are a skinnny plastic body.The numbers on the side are 0280 155 868. Are these stock LS1 injectors? Any help would be greatly appreciated.

 

They show up as 34.5 #/hr. So, given the normal variation one sees due to differences in measuring techniques, they could easily also be considered 36 #/hr. (at 43 psi vs 45 psi or similar)

LS1 injectors IIRC are 28 #/hr, and not Bosch.... I could be wrong though.

In what way does the car run terrible?

 

What was the constant programmed into the chip? Were the injectors sold used? If so did you get them cleaned and flowed?

 

I purchased the injectors used, and did not have them cleaned and flowed. The engine is a fresh 406 small block in a 1992 Z28. It seems to be running extremely rich judging by the black spark plugs and soot around my tail pipes. I do not know the constant that was programmed in to the chip. What should it be? Thanks .

 

Mail-order tune almost NEVER works; especially not the first try. Don't expect miracles.

The "value" of the constant isn't important; a better approach would be, to find out how rich/lean it is (using a wideband O2), and have your tuner adjust the constant accordingly. Like, if it's 10% too rich, have them raise the constant by 10% from whatever it is now, etc.

What happened when you adjusted the fuel pressure?

What induction system? What's the rest of the motor?

 

I have been told that mail order tunes are not the best way to go, but unfortunately where I live it is my only way. The engine uses a Holley Stealth Ram intake, Holley 58mm throttle body, AFR 195 heads, Comp retro fit XFI280 hydraulic roller cam, 1.6 comp roller rockers, Scat crank with 6'' rods, and KB forged flat top pistons. I am currently trying to set up an appointment at the nearest speed shop to put the car on the dyno and check my air/fuel with a wide band sensor. Thanks for all the info. The fuel pressure is now set on 42lbs with vacuum line off. Should I try to go lower?

 

Take it contextually please. If his value is set for say a '19 lb.' injector, then.... or if he didn't know...

Trying to get frames of reference on this site can be... well, you know.

 

Right: rather than try to ask what the "right" number is, approach it from the angle of determining how far off the results it currently produces are, and modify it accordingly. For all anybody knows, your tuner may already have the "right" "value" of that constant in there already, but it just doesn't work in your setup.

Dyno tuning with a wideband is the best way. You'll learn alot. Whyever it is that you think you're "stuck" with mail-order tuning, having hard measured repeatable reliable meaningful data will help zero in on the right changes.

I don't know why you feel like you're "stuck" with not tuning it yourself. That's really the only way you'll ever get it 100% "right", for YOU and the way YOU want it to be. https://www.thirdgen.org/forums/diy-prom/ There's lots of help and info available.

 

Sofakingdom, where did you find the information on the injectors?

 

Google

It led me to Stan Weiss' database

 

amazing what you can find if you type a few words n numbers in..