I just changed my fuel pump for my 4.9 , replaced it it with a Bosch 69222 from Rockauto but when I turn on the key I only get 10psi of pressure.
I was expecting (40-45) psi since this was supposed to be for the V6, did I get the wrong pump ????

Sounds like they shipped the one for the duke

Did you check the number etched on the outside of the pump housing to verify the correct part number before installing?

I never use Rock Auto, I have never had a good experience with them; incomplete product packaging, wrong parts, defective parts, multiple shipment to get correct parts. I get better prices by shopping locally and dealing with only two local auto parts stores.

Delphi or Delco only for fuel pumps.

quote Originally posted by f85gtron: Sounds like they shipped the one for the duke

Nope. 4cyl pump will push 18-22psi max easy. 4cyl uses 9-13psi and that's set by the TBI regulator.

Max PSI, like pinching return line, is for test only because can damage most pumps. Regulator bleed off extra and return to tank so FP see gas flow to cool and lube it.

bad pump or something else is causing his problem.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

Did the pump come with a new piece of hose to attach it to the sender assembly? (that short piece of hose on the top of the pump) And if so, did you use it?

The first time I replaced the fuel pump in my Fiero, I decided not to replace that little hose, because the original looked OK. A week later, I was dropping the tank again because it ruptured.

Maybe his regulator is stick wide open? Check to see if pressure comes up with pinch return test, if yes, then test regulator on top of fuel rail.

Have had great luck using the Bosch 69225 fuel pump which duplicates the EP381 flow and pressure capability. Not familiar with the Bosch 69222 but that may be the one for the stock 2.8L..
Causes of low fuel pressure
Bad Regulator
Crimped feed hose
Wrong, Defective or bad fuel pump
Leakage at the connection hose or pulsator in the fuel tank
Bad wire connection

My guess-bad regulator but test by temporarily pinching the return line and measuring the pressure at the Schrader valve on the rail. When the pressure rises to 43 psi stop the test. If you don't read 43 psi your problem is most likely located at the connection in the tank.
BTW, if you replace the small hose that attaches the fuel pump to the supply line, (where the pulsator was) YOU MUST use J30R10 submersible fuel injection hose and fuel injection clamps. Std fuel injection hose will deteriorate with time.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

[This message has been edited by Dennis LaGrua (edited 08-03-2016).]

OK I dropped the tank, removed the fuel pump and discovered the ground wire was loose now I have 40 PSI.
The reason I changed the fuel pump was because the old one wouldn't hold pressure and the car didn't idle without holding down the gas pedal.

Well after dropping the tank twice and replacing the pump it still won't idle .............................

quote Originally posted by Fiero Tom: OK I dropped the tank, removed the fuel pump and discovered the ground wire was loose now I have 40 PSI. The reason I changed the fuel pump was because the old one wouldn't hold pressure and the car didn't idle without holding down the gas pedal. Well after dropping the tank twice and replacing the pump it still won't idle .............................

If it starts, runs and will not idle; check the idle air control motor that is bolted on the throttle body. I've replaced a few bad ones on other cars.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

quote Originally posted by Dennis LaGrua: If it starts, runs and will not idle; check the idle air control motor that is bolted on the throttle body. I've replaced a few bad ones on other cars.

Yeah I thought that might be the case, it tries to idle at less than 500rpm when cold and in Park.

Still not running I replaced the Idle Speed Control Motor and the car won't idle without my foot on the gas and it idles very rough even then.