I have upgraded my injectors and maf to an 80mm pro m calibrated for my s/c and 42# injectors. Put it all together, and now it will barely start, and no way it will idle. I assume it is running rich, sputters....black coming out of exaust. I have checked and double checked to make sure it is all put back together correctly and have run codes and it all checked out good. I have been told that I may need to tune, but isnt that why the maf is calibrated for the 42# injectors and boost? If you have to tune it to get it all to work, then what is the purpose of paying to have it calibrated? If anyone may know what to check next it would be greatly appreciated. Thanks
Is this normal?
- Thread starter leon_reynolds
- Start date
im gonna take a wild guess and say the 42# injectors are too big for only 7 psi and like you said your running rich. And from your sig it doesnt look like you have an aftermarket H/C/I combo done so you can i ask why you would run that big of an injector with a stock/near stock engine and a blower...id say try 30 lb injectors, or a H/C/I combo....but im no expert
srothfuss
Last night I stabbed the same guy 7 times in a row
You're deffinently running rich. The MAF only tricks the computer to run with the 42# injectors, but the pulse/dwell cycle of the original 19# injectors are still programed into the ECU. A tune will remedy most of the issues you experience or a stand alone tuner / wideband O2.
Michael Yount
Mustang Master
Did you buy your maf new or used? If new - was it purchased recently? If so, I'd contact ProM (or their new incarnation) and talk with them first about what it's doing. It should idle/run reasonably well with their calibration.
Start up can be a problem because the computer holds the injectors open for a specific period of time -- and with 42's compared to 19's you're getting over twice as much fuel at start up -- it's simply flooding. The ONLY way to remedy that permanently is to alter that parameter in the ecu with chip/tweecer/pms. Temporarily you can try starting with the gas pedal on the floor. I believe that keeps the engine from injecting so much fuel at start up.
Here's ideal - have the 80mm calibrated for 19# injectors, and have ProM send you a multi-point (it's like 21 or 31 points) voltage vs. mass flow transfer function. Use your tuning device to load the transfer function into your ecu. Then use your tuning device to select the size injector you're using. That should match things up perfectly. But it won't help the start up fuel issue -- your tuning device should be able to access the tables that control start up fuel -- and reduce it.
Start up can be a problem because the computer holds the injectors open for a specific period of time -- and with 42's compared to 19's you're getting over twice as much fuel at start up -- it's simply flooding. The ONLY way to remedy that permanently is to alter that parameter in the ecu with chip/tweecer/pms. Temporarily you can try starting with the gas pedal on the floor. I believe that keeps the engine from injecting so much fuel at start up.
Here's ideal - have the 80mm calibrated for 19# injectors, and have ProM send you a multi-point (it's like 21 or 31 points) voltage vs. mass flow transfer function. Use your tuning device to load the transfer function into your ecu. Then use your tuning device to select the size injector you're using. That should match things up perfectly. But it won't help the start up fuel issue -- your tuning device should be able to access the tables that control start up fuel -- and reduce it.
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