I checked my fuel pressure today. It sits at 40 psi at idle....when I accelerate it holds at 40 but when I let off the gas it drops to 30 psi? Could my fuel pump be going out or maybe something clogging up the strainer? Here's the problem I'm having.. when I'm driving it.....if I give it gas it goes (pretty smoothly...no miss) but feels like something is holding it back....then all the sudden, it takes off. Its really weird. The best way I can describe it is as if someone had a rope tied to it and then let it go all the sudden. I've replaced the plugs/wires/coil/opti/ O2's on both sides. Thanks for any advice!




95 T/A converted to M6, 3.42's LT4 hotcam kit w/ ported/polished LT1 heads 2.00/1.56 valves 1.6 rr's, Moroso CAI, 52 mmtb, LT4 knock module, !CAT, TPIS headers, Flowmaster, electric cutout

 

That fuel pressure seems pretty normal. I think the FP is supposed to be around 41-47 at idle without vacum. Im not for sure on that number. But driving around, 40 seems about right, and then when you let off the gas it will drop pressure. The motor is pulling more vacum when you let off the gas the fuel pressure will drop. All that seems fine. I may start checking for other stuff.

 

CRAP! I was hopin that was the prob Ohh well, thanks for the reply

 

If your fuel pressure is steady while accelerating then I doubt it's your fuel supply. As stated above, there's a vacuum line attached to your fuel pressure regulator. This line causes fuel pressure to rise when accelerating and drop when decelerating. At WOT your fuel pressure should be steady in the 40 - 46 psi range. Check for knock, the PCM could be pulling timing due to real or false knock. How's your plugs, wires, air filter?

 

I haven't ran a datamaster log in a few weeks, but there wasn't any knock issues that I can recall. The plugs/wires/O2/opti/coil/coil wire are all new. I don't know where else to really look. Thanks for the reply!

 

Pull of the EGR valve and clean it real well. Check it with a hose and suck on the hose to see if it moves back and forth easily without sticking. Replace the gasket and tighten to spec. Also clean the throttle body and replace the gasket for it too.

 

The EGR valve has been removed and a block off plate installed. I'll check out the TB though! Thanks!