Just was wondernig if anyone knows what the specs are of the lift pumps on our trucks. I can hear mine running, but had a couple misses on expressway, got home opened t valve and nothing came out. So gonna check it out this week, its a heath pump with about 15k miles on it. Reason I is when was at Advance Auto other day for a unrelated part, seen a mr gasket lift pump for $60, just looked it up, its 4-7psi and 35 gph. Seemed like decent deal if its enough flow, but that seems low to me. Thanks

http://www.dieselplace.com/forum/showthread.php?t=37902&highlight=pph

I know I did not answer your question but the culprit of your LP not working may be your OPS. Unfortunately, bad OPS can cause LP not functioning. Check the OPS by measuring the voltage to the LP connector.

If you have to change it, make sure it is the ACDelco OPS.

Spec is between 3 to 6 for standard. Some people put in the LP for 93 which is a little bit higher closer to Heath HO LP.

http://www.dieselplace.com/forum/showthread.php?t=37902&highlight=pph

Deezel, I think that PPH, is pounds per hour, found a spec that diesel is roughly 7.29 lbs per hour, So if its as simple as dividing it out, 115lbs hr/7.29 lbs = 16 gallon hour. Which puts that pump within spec.

I already have a relay setup on my ops, and I have confirmed it has power.

I know I did not answer your question but the culprit of your LP not working may be your OPS. Unfortunately, bad OPS can cause LP not functioning. Check the OPS by measuring the voltage to the LP connector.

If you have to change it, make sure it is the ACDelco OPS.

Spec is between 3 to 6 for standard. Some people put in the LP for 93 which is a little bit higher closer to Heath HO LP.


ditto on the OPS. the LP pulls too much current and cooks the contacts inside the OPS then the LP dies.

Deezel, I think that PPH, is pounds per hour, found a spec that diesel is roughly 7.29 lbs per hour, So if its as simple as dividing it out, 115lbs hr/7.29 lbs = 16 gallon hour. Which puts that pump within spec.

I already have a relay setup on my ops, and I have confirmed it has power.

Cool that you have the relay. Needs to be put on your signature.
So, if you are sure that the LP is bad, then all you can do is changed it and see if it solved your problem.

Cool that you have the relay. Needs to be put on your signature.
So, if you are sure that the LP is bad, then all you can do is changed it and see if it solved your problem.

Sorry about the signature, I should have thought of putting it in, i wired in relay about a year ago and forgot to add it to the sig. I took care of that now.

JMJNet, your right next logical step is to replace the lift pump since I know that seems to be most likely cause. Reason I asked for the specs was looking for a more cost effective alternative to the factory or heath pump for $130. Seen that mr gasket for $60 thought it might be worth a try if it could supply enough fuel. Or if anyone knows of any other good pumps that may last a longer.

As alway, thanks for the input.

I used delphi FP905, which is supposed to be for 93 model year (mechanical IP). It has a slightly higher pressure than the one spec for 94+ year. I bought it on the net. I am not sure on the longevity of it yet since I only have it for about 5000 miles. Send me a PM if you want to get the Delphi LP.

I am leaning more towards ACDelco or Delphi (same thing) pump since they are built more to spec.

Lift Pump Specs for a factory stock '95 6.5TD in all light duty vehicles:

The LP only operates during CRANK via the LPR, and after the engine starts via the OPS- requires 4 PSI minimum to activate LP.

FLOW- Easiest method. With engine off, gear selector in drive, ignition in the crank position, LP should produce 1/2 pint in 15 seconds from the WIF drain hose (petcock fully open).

PRESSURE- Easiest method. Tapping a pressure gauge into the WIF drain hose (petcock fully open) and engine running, the LP should produce a minimum of 3 PSI.

Id suggest an AC Delco unit for any of these replacement parts, be it LP, OPS, or LPR.

Does your OPS relay activate the LP during the initial glow plug cycle/WTS?
Where did you get it, and how much? Got a part number by chance?
I ask because Im considering getting one of those myself should my new OPS fail.
Thanks

Does your OPS relay activate the LP during the initial glow plug cycle/WTS?
Where did you get it, and how much? Got a part number by chance?
I ask because Im considering getting one of those myself should my new OPS fail.
Thanks

Basically all I did was get a quality relay, was a fuel injection relay for a Honda or something, I will see if I can still see the part number. But all I did was hook the current hot wire to lift pump to the trigger wire on the relay, then put a fused feed from battery to actually run the lift pump. Only cost was some wire and about $10-20 bucks for the relay. It operates as factory wired this way and ops only has to power the relay.

I probably won't have a chance to work on it till this weekend now. I bought the truck with a bad pump, put about 15k miles on the Heath HO. How many miles is typical life of these lift pumps.

This one was done by HowieE, member of this forum on relay. There is also a write up in the other forum that you have to pay although the article is free.

http://mysite.verizon.net/vze54tx9/id13.html

Walbro FRB-5 pumps 2 liters a minute compared to the 1 liter a minute my stock lift pump put out. iirc Greg at lubrication specialists sells them for a very good price.