open loop maf tuning
#1
open loop maf tuning
I'm redoing a tune for my buddy's truck. It's a 99 4.8 whipple charged on 8lbs, Walbro 255, and 42 pound injectors. The truck still has a 1bar map sensor. So, since a speed density tune is out of the question. The proper way to tune it with the 1 bar map seems to be with the maf.
I have put the truck in MAF ONLY mode by disabling dynamic airflow at 1rpm and re enabling it at 2rpm. The problem is on my MAF error config, in my scanner, I am getting big afr swings per cell.
For example, In the cell 3000hz, I will be getting the average count close to 0, but the min and max will be -20 and +20 respectively. It goes very rich on decel and lean on acceleration.
Does, anyone have any suggestions to what the problem might be? I have dfco, cot, and ltfts turned off. I am also forcing open loop via the scanner. I've used my config on other trucks and never seen swings like this, so that rules out the config being wrong.
Also, does this sound like an injector problem to you? I haven't check the injector settings yet, because I haven't got a chance to look at the P/N on the injectors. I have adjusted the injector flow rate.
This is a 99 truck with the vaccum fuel pressure regulator. Should injector flow rate be flatlined? Ive tried it both ways.
Sorry for the novel.
I have put the truck in MAF ONLY mode by disabling dynamic airflow at 1rpm and re enabling it at 2rpm. The problem is on my MAF error config, in my scanner, I am getting big afr swings per cell.
For example, In the cell 3000hz, I will be getting the average count close to 0, but the min and max will be -20 and +20 respectively. It goes very rich on decel and lean on acceleration.
Does, anyone have any suggestions to what the problem might be? I have dfco, cot, and ltfts turned off. I am also forcing open loop via the scanner. I've used my config on other trucks and never seen swings like this, so that rules out the config being wrong.
Also, does this sound like an injector problem to you? I haven't check the injector settings yet, because I haven't got a chance to look at the P/N on the injectors. I have adjusted the injector flow rate.
This is a 99 truck with the vaccum fuel pressure regulator. Should injector flow rate be flatlined? Ive tried it both ways.
Sorry for the novel.
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I'm redoing a tune for my buddy's truck. It's a 99 4.8 whipple charged on 8lbs, Walbro 255, and 42 pound injectors. The truck still has a 1bar map sensor. So, since a speed density tune is out of the question. The proper way to tune it with the 1 bar map seems to be with the maf.
I have put the truck in MAF ONLY mode by disabling dynamic airflow at 1rpm and re enabling it at 2rpm. The problem is on my MAF error config, in my scanner, I am getting big afr swings per cell.
For example, In the cell 3000hz, I will be getting the average count close to 0, but the min and max will be -20 and +20 respectively. It goes very rich on decel and lean on acceleration.
Does, anyone have any suggestions to what the problem might be? I have dfco, cot, and ltfts turned off. I am also forcing open loop via the scanner. I've used my config on other trucks and never seen swings like this, so that rules out the config being wrong.
Also, does this sound like an injector problem to you? I haven't check the injector settings yet, because I haven't got a chance to look at the P/N on the injectors. I have adjusted the injector flow rate.
This is a 99 truck with the vaccum fuel pressure regulator. Should injector flow rate be flatlined? Ive tried it both ways.
Sorry for the novel.
I have put the truck in MAF ONLY mode by disabling dynamic airflow at 1rpm and re enabling it at 2rpm. The problem is on my MAF error config, in my scanner, I am getting big afr swings per cell.
For example, In the cell 3000hz, I will be getting the average count close to 0, but the min and max will be -20 and +20 respectively. It goes very rich on decel and lean on acceleration.
Does, anyone have any suggestions to what the problem might be? I have dfco, cot, and ltfts turned off. I am also forcing open loop via the scanner. I've used my config on other trucks and never seen swings like this, so that rules out the config being wrong.
Also, does this sound like an injector problem to you? I haven't check the injector settings yet, because I haven't got a chance to look at the P/N on the injectors. I have adjusted the injector flow rate.
This is a 99 truck with the vaccum fuel pressure regulator. Should injector flow rate be flatlined? Ive tried it both ways.
Sorry for the novel.