Blownpiston

1993 Grand Am SE. Quad 4, S.O.H.C. Automatic. What to check to isolate problem? Starts good, Idles well, shifts through lower gears smooth. Has lack of power, will only run 50 mph. flat out on road. Difficulty pulling hills, very slow. I searched our site, and seems i start with Fuel pressure check. Fuel filter change, and clean throttle body. Check maf, and tps. Sure seems like a fuel problem. Have new plugs, ign. coil pack, vacuum lines, trans. filter and fluid. Anyone have this happen to them? and what do you guys suggest for a plan? What should fuel pressure be? How to check the fuel pressure regulator? Thanks to all!

xeroinfinity

How many miles on this 93 ??

Could also be a clogged Coverter, though I would check the fuel pressure and replace the fuel filter first and see if that helps.

Not exactly sure what the fuel pressure should be, probly close to 40 psi.
Though to check this on your 2.3 Quad you need an adapter hose that comes with a guage, sold/rented at most part stores.

Another thing to check while the car is running, pull off the vacum line from the fuel pressure regulator , if fuel come out your FP reg. is bad.

Hope that helps.

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1999 Grand Am SS 3.4 OHV

Blownpiston

xeroinfinity, Thanks! I will do all these checks Monday morn.With all the help on our site, i know the answer is there somewhere.