A question about fuel pressure

[NC Rob]

I have a 94 Chevy, 2500, 4wd, with the 6.5 TD. I have a question about fuel pressure, or in my case, lack of.

I just put in a new fuel pump, and fuel pump relay. I also replaced the fuel cap, and still get a swoosh of vacumn when I open the cap. I even ran it without the cap to see if that would eliminate the vacumn. The vacumn was eliminated, but I still have hesitation upon hard acceleration, and occasionally, the engine will just die from lack of fuel, or at least that is what appears to be the cause.

I did the fuel pressure test as described in the FAQ section. Well, to my surprise, I have no fuel pressure, but strangely I have vacumn at the bleeder valve.

I have replaced the PMD with a remote unit. My injection pump is the one with the green tag, replaced by the dealer at approx 110,000 miles. I know have 155,000 miles on the truck.

Any help would be greatly appreciated. I won't be back online till this evening, so I won't be able to respond right away.

Thanks so much, and thanks for such a wonderful forum. I have learned so very much from my visits here.

[Kennedy]

Sounds like the OPS is acting up. We make a full stand alone lift pump control harness that will ensure that you have proper operation of your lift pumps with the reliability needed.

Power, ground, and switched power is all you need to ask of the vehicle's electrical system. Then plumb my OPS (NON load carrying) to a good source, make the connection at the pump and you are done. You get prime at key up, and manual operation via push buton for bleeding filters...

[gmctd]

And check the Lift Pump Fuse in the rubber fuse-holder, up on the firewall by the Lift Pump Start Relay - btw, your Inj Pump is in very good condition, to be pulling vacuum at the water drain.

[NC Rob]

Thanks Guys. I appreaciate the responses.

Mr. Kennedy, I will look into your product. I like the remote switch method for bleeding the fuel filter unit. Much better then the crank method.

GMCTD, I will check the fuse you spoke of. I am glad my injection pump is good. I thought I was going to need a new one. Now I know how I got vacumn. Thank you very much.

Thanks again guys. Talk to you later.

Robert