1996 S10 2.2 2x2 Fuel Pressure?

[mel_woos]

What is the procedure for testing fuel pressure for a 1996 Chevy S10 2.2L 2x2? Where would I connect the fuel test gage, what type, and where would I get one? Truck is hard to start in AM, takes 3 to 5 attempts before she purrs. Truck sits outside in driveway on a 10 degree upward slope. Installed 4 new injectors and fuel pressure regulator.
Gilbert,AZ

[MT-2500]

Look for a scrader type valve hook up like the old R12 ac fittings on the fuel line or fuel rail.
If it does not have one you will have to tap into the fuel line at filter or where it goes to engine.
You will need a fuel pressure test gauge that will read high pressure up to a 100 lbs.
Auto parts places should have one or a auto repair tool man.
Specs are 41/47 lbs of pressure.
Look for 45-46 lbs on a cold start.
And make sure no a fast leak down after key is off.
MT

[Blue Bowtie]

The gallery feed injectors used on that engine are flow rated at 3 BAR (43.5 PSIG). The FPR should regulate the fuel to 44 PSIG, ± 3 PSIG with no vacuum applied to the regulator, like MT wrote. With a running engine and idle vacuum, it should regulate at 37 PSIG, ± 3 PSIG.

The pressure test requires the use of a line adapter at the fuel filter, since there is no Schrader valve on a '96 134 in a truck.

Been there.

[mel_woos]

Thanks for the data/help. My S10 does not have a valve in engine bay, I'll have to cut fuel supply line. When I have time I'll get back with results.

[16th hippy]

DON"T CUT! there is an adapter you can buy to tap in at the fuel filter.....why oh why did they not put one on a '96 but my '98 has one.

[mel_woos]

I did find an adapter which replaces the fuel filter. Fuel pressure when running was OK 35-37. Key off pressure increased to 41-45. After 15 minutes with key off pressure dropped to 10-20. Key on, no pressure increase. Cycled key on/off no change. After 3 cranks engine coughed and fired, pressure at 35. Removed vacuum from pressure regulator (engine running), pressure fluctuated between 30-37 with rapid needle movement. Unsure which relay goes to what in the glove box there are 3 relays. I swapped relays to see if there was any change, there was not.
??????

[MT-2500]

Originally Posted by mel_woos

I did find an adapter which replaces the fuel filter. Fuel pressure when running was OK 35-37. Key off pressure increased to 41-45. After 15 minutes with key off pressure dropped to 10-20. Key on, no pressure increase. Cycled key on/off no change. After 3 cranks engine coughed and fired, pressure at 35. Removed vacuum from pressure regulator (engine running), pressure fluctuated between 30-37 with rapid needle movement. Unsure which relay goes to what in the glove box there are 3 relays. I swapped relays to see if there was any change, there was not.
??????

Fuel pressure is low.
The fuel pressure regulator or fuel pump is weak.
You need 45-46 lbs on a cold engine cranking.
Work on fuel pressure end.
Check direct fuel pressure at fuel pump to fillter with the return line blocked or pluged if it has a return line.
Full /direct fuel pump pressure should be over 75 lbs.
MT

[jasonw1981]

sounds like a fuel pump issue.

[MT-2500]

Originally Posted by jasonw1981

sounds like a fuel pump issue.

Lets not forget proper testing before throwing a fuel pump at it.
MT

[16th hippy]

fuel pump relay should be in underhood power center.

[mel_woos]

There was insufficient pressure at fuel pump. Replaced fuel pump. Engine starts 1st crank. Thank you all.
New problem:
After 8 days of daily driving I get MIL on. OBDII reader code P0137. It also indicates that the catalyst and EGR monitors are not ready. Day 10 MIL out catalyst and EGR monitors are still not ready. This error, P0137, 1st appeared after installing 4 injectors, 180 thermostat(original was 180), coolant temp sensor. Last year I installed both O2S, HO2S and Cat all new.
Truck runs great.
Any ideas?

[MT-2500]

You need a 195 degree stat in it for the engine to warm up to proper tempt and for the computer system to work right.
Put one in it and see what it does.
MT

[mel_woos]

OK I will, but, if the truck was equipped with a 180 ( I bench test both new and old stats in same container of water and them both opened at the same time, 180. The problem with the old was it was not closing completely so the truck was running a about 160 for 2-3 years and never had P0137 code) why now should the system need to look for 195? I purchased this truck new, in AZ, and have done all the work on it myself. I have a 195 because it is the "Recommend" stat. I put it in after installing the injectors and noticed it was running hotter then before so I put in the 180 and it's running where it had been since 1996.

[MT-2500]

The truck needs a 195 degree stat for the engine and pcm to work right.
Clear code and install the 195 stat and see what it does.
If code comes back then post back code no and we can go from there.
MT.