96 k1500 rough idle, power loss

[nbubak]

My 96 k1500 5.7 350 is idling rough and when I accelerate there is a loss of power. I recently installed a new fuel pump and filter. When I put it in to D it hesitates and acts as if it wants to die but hasnt yet. I checked the schrader valve on the fuel lines and I have good pressure. If I could get help with diagnosing my problem, Id be very appreciative!

[tblake]

Couple things. Does the fuel pressure hold after you shut the key off, or drop off right away? When your first start it in the morning when its cold, does it start easy or crank a while? You could have a leaky fuel pressure regulator or a couple leaky injectors. I replaced my FPR a few months back, and now I have an injector sticking it seems like.

When was the last time the Cap and Rotor were replaced? The track through the rotor for #3 cylinder winds next to a few other cylinders. Over time, the sparks for #3 can track to a different plug due to a failing distributor cap. If you have a bunch of miles on your cap and rotor, I'd replace them.

[nbubak]

When I turn off the key fuel pressure drops off right away. and in the morning it cranks awhile before starting up. I bought the truck in September and havent done anything with cap and rotor.

[tblake]

Take the plastic vortec intake off the throttle body. Find a small flashlight, open your throttle and use the flashlight to look inside towards the lower intake manifold on the passenger side. Check right below the fuel pressure regulator and see if it looks all washed from fuel. Sounds to me like your regulator might be leaky.

[Bob B]

Originally Posted by nbubak

My 96 k1500 5.7 350 is idling rough and when I accelerate there is a loss of power. I recently installed a new fuel pump and filter. When I put it in to D it hesitates and acts as if it wants to die but hasnt yet. I checked the schrader valve on the fuel lines and I have good pressure. If I could get help with diagnosing my problem, Id be very appreciative!

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You say the schrader valve has good pressure,,,
Did you measure with a pressure gauge Or just give a squirt?
It needs around 60 lb.
Bob B

[nbubak]

i dont have a pressure guage so i just used a screwdriver

[autotech234]

if it is running poorly all the time you may have more than one problem. if it clears up after it is started it is most likly just the regulater leaking. if it does not clear up you may have a sticking inj. if you need info on how to check this let me know. i will be glad to help.


10year ase master tech +L1

[nbubak]

Thanks guys I think its just my FPR, I left work today and she ran fine! I think Im gonna just do a small overhaul, new cap and rotor, plugs and wires and pry injectors. Ill pry need help with that, although my roommate is an ASE Master tech, but never wants to help! haha

[autotech234]

I will post alldata service and repair for f.p.r. so check back

[autotech234]

Labor Skill
Level Mfg.
Warrany Standard
Fuel Pressure Regulator

Replace B 1.4 1.8








REMOVAL PROCEDURE

1. Disconnect the negative battery cable.
2. Relieve fuel system pressure. Refer to Fuel Pressure Relief Procedure . See: Service and Repair
3. Remove the upper manifold assembly. Refer to Engine Mechanical .

DISASSEMBLE PROCEDURE

1. Disassemble the fuel pressure regulator snap ring retainer.
2. Disassemble the regulator assembly and the O-rings.
3. Discard the O-rings. NOTE : If the fuel pressure regulator is to be reinstalled, inspect the filter screen (if equipped) for contamination. If contaminated, remove. Discard the filter screen.

ASSEMBLE PROCEDURE

1. Lubricate the new O-rings with clean engine oil.
2. Install as an assembly, backup O-ring, large O-ring, filter and small O-ring.
3. Assemble the regulator with vacuum tube pointing down and snap ring retainer.

INSTALLATION PROCEDURE

1. Install the upper manifold assembly. Refer to Engine Mechanical .
2. Disconnect the negative battery cable.

[autotech234]

Replacement (Upper) intake





REMOVAL

1. Disconnect the battery negative cable assembly from the battery negative terminal.
2. Remove the air cleaner assembly. Refer to Powertrain Management.
3. Remove the wiring harness connectors and the brackets and move aside.
4. Remove the throttle cable and the bracket from the upper intake manifold.
5. Remove the cruise control cable, (if equipped).
6. Remove the fuel lines from the intake to the rear of the block. Refer to Powertrain Management.
7. Remove the ignition coil and the bracket. Refer to Starting and Charging
8. Remove the upper intake manifold.

INSTALLATION

1. Install the upper intake manifold gasket.
2. Install the upper intake manifold. Use care not to pinch the injector lines between the upper and lower intake manifolds.
3. Install the upper intake manifold bolts. Note the marks made at disassembly for proper stud location. Install the two corner studs first in order to help align the two halves. ALLDATA Editor NOTE: Other than the two torque passes listed below, the OE Manufacturer did NOT address or supply a bolt tightening sequence for the upper Intake Manifold for this model year, or other model years where this 2 piece manifold setup is used. A "Play It Safe" final tightening sequence would be to tighten from the center most bolts to the outer most bolts.
4. Tighten the bolts in two steps:

1. Tighten the bolts on the first sequence to 5 Nm (44 inch lbs.) .
2. Tighten the bolts on the final sequence to 10 Nm (88 inch lbs.) .

5. Install the purge solenoid and bracket. Refer to Powertrain Management.
6. Install the ignition coil and bracket. Refer to Starting and Charging.
7. Install the PCV hose et the upper intake manifold.
8. Install the fuel lines from the intake at the rear of the block. Refer to Powertrain Management.
9. Install the cruise control cable (if equipped).
10. Install the throttle cable and bracket from the upper intake manifold. Refer to Powertrain Management.
11. Install the wiring harness connectors and brackets.
12. Install the air cleaner assembly. Refer to Powertrain Management.
13. Connect the battery negative cable assembly to the battery negative terminal.

o Tighten the bolt to 15 Nm (11 ft. lbs.) .