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6.5 turbo deisel lift pump problem?

Monte Sisk

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Location
Princeton ky
95' turbo deisel 6.5 getting alot of air in fuel line. Getting fuel to come out of filter and t-valve by jumping fuel relay but when engine running no fuel will come out of t-valve and engine dies. After bleeding air out of lines truck runs perfect.
 
Oil pressure sensor is dead most likely. It carries the power to the liftpump so when the engine dies in a crash, the lift pump quits pumping fuel onto the hybrid you just squished.

Test power to and from it to verify, then Get a new ops and a relay harness kit from leroydiesel.com. The relay harness plugs into everything easily and takes the electric load off the ops so the new one wont burn out.

Options: you can build the harness yourself, get the ops as an AC Delco only- others are crappy.

Leroy also makes an ops extension hose that has a ground carried inside the hose that makes replacing the ops much easier. I had my own own made at a hydraulic hose shop, but it doesn't carry the ground so I had to add an extra ground wire, and mine was more $ than Leroys. I didnt know of him when I made mine:eggface:.

That takes care of the fuel issue, as for air in the lines, you might be aerating the fuel because of it. Or a hose is loose somewhere and it is sucking it in. On the front of the injection pump there is a 4" long 1/4" diameter rubber hose (fuel return hose) that goes to a metal line connecting both sides of the injector return lines. Buy a piece of clear tubing and replace the lack hose. With engine running, watch for bubbles. Getting 1 trapped in there is ok, but if you have a stream of bubbles, it hat is indicitive of an air leak getting in. For the rest of the rigs life, instant diagnosis for the problem at a glance.

Btw, welcome and spend some time here reading through the stickys, a lot of $$ to be saved and improvements that can pay for themselves.
 
Oil pressure sensor is dead most likely. It carries the power to the liftpump so when the engine dies in a crash, the lift pump quits pumping fuel onto the hybrid you just squished.

Test power to and from it to verify, then Get a new ops and a relay harness kit from leroydiesel.com. The relay harness plugs into everything easily and takes the electric load off the ops so the new one wont burn out.

Options: you can build the harness yourself, get the ops as an AC Delco only- others are crappy.

Leroy also makes an ops extension hose that has a ground carried inside the hose that makes replacing the ops much easier. I had my own own made at a hydraulic hose shop, but it doesn't carry the ground so I had to add an extra ground wire, and mine was more $ than Leroys. I didnt know of him when I made mine:eggface:.

That takes care of the fuel issue, as for air in the lines, you might be aerating the fuel because of it. Or a hose is loose somewhere and it is sucking it in. On the front of the injection pump there is a 4" long 1/4" diameter rubber hose (fuel return hose) that goes to a metal line connecting both sides of the injector return lines. Buy a piece of clear tubing and replace the lack hose. With engine running, watch for bubbles. Getting 1 trapped in there is ok, but if you have a stream of bubbles, it hat is indicitive of an air leak getting in. For the rest of the rigs life, instant diagnosis for the problem at a glance.

Btw, welcome and spend some time here reading through the stickys, a lot of $$ to be saved and improvements that can pay for themselves.
Thanks for the reply! Greatly appreciated and I will b checking ops tmorrow. Thanks again.
 
Just a note. if checking the OPS for voltage by unplugging the lift pump - It can show full voltage there, but still not pass enough amps to run the lift pump.

If your OPS is putting out any volts at all, it is probably enough to trigger a relay. So if you are tight on money or time and you have voltage to the lift pump plug - but not enough juice to run the lift pump, You can try just doing the dual lift pump relay upgrade or buy leroydiesel.com 's lift pump relay kit.

Do some searching and google dual lift pump relay upgrade. If you do it yourself, Do not do it as shown in most of the schematics. Do not cut or splice anything. Do it like leroy does his.

I have 2 vehicles that have been running for years on OPS's that would not run a lift pump before they were connected to the relay.
 
No matter the issue with your '95, if you don't have Leroy's harness, buy it. It's top quality and does the job. Keep in mind that I had already built my own harness and had been running it for years - I still bought Leroy's and it was a great investment. The harness I made is gone and Leroy's is proudly installed.
 
No matter the issue with your '95, if you don't have Leroy's harness, buy it. It's top quality and does the job. Keep in mind that I had already built my own harness and had been running it for years - I still bought Leroy's and it was a great investment. The harness I made is gone and Leroy's is proudly installed.

The advice is the same for any 95 or older
 
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