Mmhmmm I have been having a hell of a time with my car this year. Long story short, is the car does not seem right in any way as far power is concerned, its a little heistant at idle and at WOT from 5K and above it cuts out bad. It really missfires.... but it does it more times than it doesnt.

I replaced the optispark, checked the wires and the opti connector (4 pin). I have new plugs and wires on the way but not here yet, and a new ICM I will be installing. I did a fuel filter less than 3k miles ago and this didnt start doing this till about 2500 miles after that. I mean i could do another filter but I just dont know what to do. Other than throw parts at its.




But we took the car out last night and put a load on it with a fuel pressure guage attached to the rail and attached to the windshield

here are our results..

With...

Key on Engine off: 38-40 psi
Key on Engine running in park: 38ish
Slowly pushing the accelerator in park: When i did it slowly from idle to 3k it dropped to 35psi and I pegged it hard and dropped to 32....


took the car for a spin. We had to look for dry pavement since spining may throw off th reading.

While driving the fp stayed around 38 psi, which was fine, at a stop if I blipped the throttle it went to 41 ish, which was fine.

But we got a stetch where we could really get it in the upper rpms. When I went WOT and near the upper rpms it would freak out and the fp dropped to 30 psi just before it wanted to shift. The went back to 35-38.

Did it just like that 2-3 more times. I got one run though where it didnt blip much, it was a cleaner pull to redline and it only dropped to 34-35.... so its beginning i look like a fuel pump...

But the car has a choppy idle and it is surging, but since i have a race tronix pump in a box, it would be easier to switch that out and do the ICM.

My question is, should Fuel Pressure EVER drop?? before shifts at the upper rpms?? My car is a 383 with a hotcam with nothing much else. It seems like a lazy fuel pump.

 

My question is, should Fuel Pressure EVER drop?? before shifts at the upper rpms?? My car is a 383 with a hotcam with nothing much else. It seems like a lazy fuel pump.

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Fuel pressure should not fall at WOT,It should stay at 42-45 at WOT.

 

I had the same sinking feeling, no biggie I have a 255lph racetronix pump sitting next to me for like 2 years lol. So at least I have the next course of action. Anyone else, please feel free to help!