DRock

iTrader: (1)

My 1989 242ss with a 95 454 (not magnum) is acting up, its slow to plane up, wont really get passed 3400 rpms and anything above 2800 rpms she begins to surge down almost as if someone is cutting the fuel supply out and then turning it back on... Only under load - the engine sounds fine out of gear and will rev up to 5k no problem

Here is what I know so far:
Compression/leak down good
Quadrajet Carb rebuilt and beginning of season
ignition module replaced
wires/NGK plugs replaced
gas tank has been ran to empty and refilled 3 times now with good gas
cap and rotor replaced
oil pressure, engine temp, voltage all good

My questionable area is a Walbro Electric Fuel Pump that is stamped for 7 PSI that was apparently replaced in 2009.... could a faulty fuel pump provide this issue??

Need some advice before I spend anymore blindfolded money into my 242....

Thanks in advance

PhantomChaos

Fuel filter?

DRock

iTrader: (1)

My fault - fuel filter was also replaced

Mr Maine

Does the fuel pump take suction directly from the tank? If so there is usually a screen on the intake side of the fuel pump that could be clog with junk from the tank.

Also, electric fuel pumps have a hard time "sucking" fuel past the check valve mounted on the fuel tank outlet. There could also be junk clogging this check valve.

I would start by checking those 2 things and then either get a fuel pressure gauge to see if you are losing fuel pressure under load, or try a different fuel pump.

axapowell

Check the fitting at the tank. Usually has a check ball and spring. Remove the fitting and replace it without the check ball. If that solves it, you can either replace the fitting or not. It is there to prevent the fuel from returning to the tank so it starts faster.

Dave

DRock

iTrader: (1)

ok, so I checked the fitting on the tank and it was just a fuel barb with no anti-syphon, I would imagine you do not need one with an electric fuel pump?

Anyway, I set up a fuel pressure gauge and it showed .4 psi at idle!! Would you agree this is my problem, I did not run it on the gauge yet due to time so just got a reading at idle

axapowell

Am I reading this right .4?

If so, weak or just plain bad fuel pump. Where are you checking fuel pressure?

Dave

regalman4925

i would try a electric pump with adjustable regulator if it was me. you can get the mr gasket version of a holley blue on ebay for around 100 bucks, i have been running them for a few years and never a issue. pretty sure it sounds like a fuel delivery issue