ECU Help???

[Bernie Cunningham]

How's your fuel flow, filter, pressure?

[art leong]

Fuel pressure is 43.5 psi using a Aeromotive 1000 pump fiters are all new just 2 runs on the car.
No problem with acceleration because I can't get the tires loose in the water.
The air/fuel ratio starts way lean then gets "normal" when the car cleans up at about 4500 rpm in gear.

[Sean Haning]

Hey Art, there are a bunch of very knowledgable tuners of 2.2, 2.5, and 2.4 as well as 2.2 hybrid cars on http://www.turbo-mopar.com/forums/cmps_index.php Go over there and ask and I'm sure one of the calibration or standalone "experts" could help you out.

[Ed Wright]

Art, your air/fuel ratio will look extrememly lean at lower RPM, due to fresh air being pulled back in the collector during overlap. You need to put a muffler, or at least 18" of collector extention to know what the actual air/fuel ratio is at idle, on the converter, and launch. Once you get that dialed in you can remove it to race it. Be sure, if you are going to run it in closed loop to set the min RPM for closed loop fuel corrections higher than the RPM you will stall it on the converter. Otherwise the ECU will be pouring the fuel to it down there to try and correct what it assumes is an extremely lean air/fuel sistuation with the exhaust extention gone. If you can put a bend in the extention, that would be even better for the initial low RPM air/fuel tuning. I no longer run my FAST in closed anyway.

Good luck, Ed

[art leong]

Hi Ed. You might be on to something with my problem. Is it posible the open loop parameters are messed up. And when it gets up there in closed loop it straightens out and runs fine?

[Ed Wright]

Originally Posted by art leong

Hi Ed. You might be on to something with my problem. Is it posible the open loop parameters are messed up. And when it gets up there in closed loop it straightens out and runs fine?

Could be Art. Set the min temp or min RPM for closed loop exttremely high, and get the fueling corrected in open loop with the muffler or long header extention installed. If you get it running well warm, but it has problems cold, only change the temp correction tables to address that, or you will be changing your warm/no temp correction tuning. Remember to not let it run in closed loop at low RPM with open headers.

[NovaMan]

Just out of curiosity, is this a speed-density system or mass airflow?

[art leong]

Originally Posted by Ed Wright

Could be Art. Set the min temp or min RPM for closed loop exttremely high, and get the fueling corrected in open loop with the muffler or long header extention installed. If you get it running well warm, but it has problems cold, only change the temp correction tables to address that, or you will be changing your warm/no temp correction tuning. Remember to not let it run in closed loop at low RPM with open headers.

I'm using open loop all the way through.