How to tell pcm what # injectors you’re running with Tunercat?
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Joined: Nov 2023
Posts: 47
From: Michigan
How to tell pcm what # injectors you’re running with Tunercat?
I’ve got a 1994 z28 and I just got done with my engine rebuild and started the car for the first time, (fired right up and ran great!) I’ve got 42# injectors which is a fairly big jump from the stock 24s. I only ran it for a short bit just to see if it’d start. Now I’m looking through the tuner at software and can’t find how to tell the PCM that I’m running a bigger injector. Anyone know how?
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Joined: Nov 1998
Posts: 71,086
From: Hell was full so they sent me to NJ
Re: How to tell pcm what # injectors you’re running with Tunercat?
You have to program both injector flow rate and offsets. Flow rate has to be adjusted for the pressure at which the injector flow was rated, if not 3 bar (43.5 PSI). Ford injectors for example are flow rated at 2.7 bar (39.15 PSI). If running something other than the LT1’s standard 43.5 PSI, you have to take that into consideration as well. You manipulate that on a calculator to obtain the flow rating based on square root of the pressure ratio.
Have you seen this guide:
https://www.lt1pcmtuning.com/tips/
Have you seen this guide:
https://www.lt1pcmtuning.com/tips/
Administrator
Joined: Nov 1998
Posts: 71,086
From: Hell was full so they sent me to NJ
Re: How to tell pcm what # injectors you’re running with Tunercat?
You need to enter the new injector size in your tuner’s fuel setup. Look for the field labeled “Injector Size” or “Injector Flow” and set it to 42 lb/hr (about 433 cc/min). Make sure any injector delay or battery voltage correction settings are correct, then reflash the PCM so it knows you’re running the larger injectors.
https://www.camaroz28.com/forums/new...repair-890300/
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