high rpm power loss.

[chris2523]

my 93 mark viii has had some problems holding fuel pressure at higher rpms. ihave replaced the pump and the problem got better but is not completely solved. WOT at about 40 mph in 1st gear (dont know rpm, tach is stuck) it losses all power. when i let off the gas pedal, it comes back. i noticed the evap line has been squished flat where it turns up into the fender well. my dad thinks the tank might not be venting and theres a vacuum in the tank. can a sealed off evap line do this. not sure what else. new fpr, new fuel pump and tank strainer, and new fuel filter. i hope i didnt get a bad pump.

 

[unity]

So you are SURE its fuel pressure, as in you have a gauge hooked up?

If so next in line, and the two I would have done before the pump, would be the filter and pressure regulator. Also check vacuum line to regulator.

But something tells me its the coil packs... we will find out later if nothing else works.

 

[chris2523]

yep its most definitely fuel pressure. had a gauge hooked up and when it was good it had 35-40 psi and when it was bad it had only 18 psi. the car has 154k mi so was going to replace fuel pump anyway.

 

[papa bear]

How did the line get kinked by jacking it up or what

 

[chris2523]

i dont really know. probably my dad ran over something. he drove it off a curb once and another time bottomed out when he pulled off the highway. he had to be towed back on the road on that one.

 

[papa bear]

Did u check the fuel line to and make sure it does not have a kink also and first off replace the fuel filter and check your pressure regulator to see if it is leaking

 

[unity]

ok... good to know about the PSI reading.. not that IT is good.

Definitely do as above. You know your pump is good, but it may not be for long if its that restricted. Its a flow-back type system so its always pumping away at full force. A restriction is bad for any pump.

I had a 95 MK8 beater. It had a pinched fuel line near the passenger door/front. Was never a problem, but you can tell some idiot used that area as a lift point.... the REAL lift point in about 10" closer to the car's center.

 

[chris2523]

will make a thorough check for pinched fuel lines tomorrow and get a new filter. then see what happens.