Have any of you ever seen or heard of an engine driven lift pump. Based on the t handle test mine has quit. So I was under the truck trying to find the LP but could not find the pump attached to the frame rail. So I went to the tank and started tracing the lines back to the engine, and low and behold the lines lead me to an engine driven fuel pump that look just like a gassier.

Anyone have any idea what I have?

That is wierd, I have never heard of one on a 6.5, they had engine driven LPs on the 80's 6.2s, but changed to the electric with the body style change. I don't know if the fact that you have a van, that effects having an electric lift pump or not.

Maybe PO changed it to a mechanical? Leo

with your van if that is it in your avitar there arnt any rules. The company that decided to put it together chose what to use. The whole truck is more like a custom. Did you ever decide what ip you have? I would think you have a db2. Now if that is the case than the 6.2 section may be of more help to you. As the only thing you would haven with the 6.5 setion would be the long block.
while testing your lift pump the engine was running? when bleeding or testing your fule system you will have to crank the engine or have it running.

with your van if that is it in your avitar there arnt any rules. The company that decided to put it together chose what to use. The whole truck is more like a custom. Did you ever decide what ip you have? I would think you have a db2. Now if that is the case than the 6.2 section may be of more help to you. As the only thing you would haven with the 6.5 setion would be the long block.
while testing your lift pump the engine was running? when bleeding or testing your fule system you will have to crank the engine or have it running.

Yep Lost with out spark, I did have it running when I opened the t handle and it continued to run for about 30-45 seconds and then stalled. The IP is cable actuated so no electronics to worry with either :cool: Just got back from parts store and we found that in 1989 the 6.2 had mech LP so I have one in hand going out now to see if maybe it will fit. Funny tho, the pump is not leaking and as I remember from my gasser days the only time I ever saw a fuel pump quit they would leak. (Busted diaphragm) So maybe I have some other issue besides a fuel pump?

The mech pump also varies in speed with the engine. The faster the engine runs the faster the fuel will be pumped. The fuel pump is driven off of a lobe on the cam and a pushrod transfers the rotating of the cam lobe to a pushrod that operates the fuel pump.

I dont know if the lift pump for us electric ip is fitting for you. For most part you would be better served in th 6.2 section. You will have to bounce between the two sections till you know the diffrences between your 6.5 and our 6.5. Other than the size and ip diffrence between 6.2 and 6.5 they can share many parts.

The mech pump also varies in speed with the engine. The faster the engine runs the faster the fuel will be pumped. The fuel pump is driven off of a lobe on the cam and a pushrod transfers the rotating of the cam lobe to a pushrod that operates the fuel pump.

Yes understood: is the t test still valid? I had engine idling when I opened the t valve 1/2 turn and the engine stalled. I closed the t handle and tried to restart and never got the engine to run again. I have new batteries and the engine was spinning like new.

I can see now this truck is going to be a biotch to prim!

Yes understood: is the t test still valid? I had engine idling when I opened the t valve 1/2 turn and the engine stalled. I closed the t handle and tried to restart and never got the engine to run again. I have new batteries and the engine was spinning like new.

I can see now this truck is going to be a biotch to prim!


Problem with the mech pumps is that they only pump when the engine is rotating, so by time you get the system primed your batteries are exhausted. You should be fine with an inline LP. all you'd have to do it run the wiring for it. Factory on our trucks the Lp is powered through the OPS, so that in case of an accident diesel isn't pumped all over the place(Lp shuts off when no oil pressure is detected.)

Yep Lost with out spark, I did have it running when I opened the t handle and it continued to run for about 30-45 seconds and then stalled. The IP is cable actuated so no electronics to worry with either :cool: Just got back from parts store and we found that in 1989 the 6.2 had mech LP so I have one in hand going out now to see if maybe it will fit. Funny tho, the pump is not leaking and as I remember from my gasser days the only time I ever saw a fuel pump quit they would leak. (Busted diaphragm) So maybe I have some other issue besides a fuel pump?
The spring in the LP may be weak or broken. Leo

to prim your truck I think that while you change the filter you can refill filter by pouring in good clean fuel or fuel power service mix. This would reduce the amount of cranking that would be needed. Than after use the black knob on the filter (air bleed ) While cranking till you just get fuel and no air bubbles.

FYI the knob on my filter is WHITE.

The spring in the LP may be weak or broken. Leo

I have the pump off the struck and the spring is very week, I can easily pump by hand. The new pump is very stiff and i have to push really hard to move the thingie. Maybe this new pump will do the deal:)

I may get a 12 v pump and put inline between tank and IP for priming, I want know until I try priming the IP with the engine driven fuel pump. If it dosent prim pretty fast, it time to go back to the parts store... my wife loves me tho.. Ha,ha

I would love to have the simplisty of your truck. There is no way I would think the electric pump would be better. I read here about diffrent members electric lift pump that went bad. For you you dont have to worry about your ops, ign sw, relay. Your pump what did it cost $40.00? Mine was $85. I have put on 2 in 4 years. The 82 6.2 I used to drive I dont rember it ever needing a new pump.

I have a 93 6.2 that came out of a bus. It had the mechanical fuel pump and v-belt accessory drive. So yes there is no rules. The proceedure for my olds diesels was to crank for 30 seconds rest for a minute ,crank for 30 seconds ,open bleeder to allow trapped air to escape and repeat untill there is no bubbles. Best to unplug red wire to ip untill most air is gone then connect and start. This may take several tries. The olds diesels didn't have a bleeder if i remember correctly. They were supposed to self bleed through the return lines.

Take the short little return line off the top of the injector pump and apply 3-5 psi. max and open your fuel filter bleeder and u should force the air right out, that's what i do on my 6.2 to save batteries, etc.

Take the short little return line off the top of the injector pump and apply 3-5 psi. max and open your fuel filter bleeder and u should force the air right out, that's what i do on my 6.2 to save batteries, etc.
Dose your 6.2 have the 6.5 filter? His has the same filter as my 6.5.

i have a spin on my 6.2 , but when i had the model 80 filter that's what i did. but same pricable on the filter manager just unscrew the black bleeder on top it will still force the air out

Yes understood: is the t test still valid? I had engine idling when I opened the t valve 1/2 turn and the engine stalled. I closed the t handle and tried to restart and never got the engine to run again. I have new batteries and the engine was spinning like new.

I can see now this truck is going to be a biotch to prim!

Yours is NA so it gets a mech lift unless you want to upgrade to elect but protected with a OPS, the mounting boss for the mech lift is where turbo drain goes on the 6.5TD.

For diagnostic use the gage test outlined here http://www.dieseltowingresource.com/showthread.php?t=6872 disregard the electrical stuff you ain't got, but connect test gage with engine running to drain tee, check with a gage while driving of pressure goes to 0 you got probs, but usually a mech pump has weep hole that leaks fuel to let you know if diagpragm in the pump is bad.

I would love to have the simplisty of your truck. There is no way I would think the electric pump would be better. I read here about diffrent members electric lift pump that went bad. For you you dont have to worry about your ops, ign sw, relay. Your pump what did it cost $40.00? Mine was $85. I have put on 2 in 4 years. The 82 6.2 I used to drive I dont rember it ever needing a new pump.


Electric pump required for turbo 6.5 not enough delivery volume for turboed trucks from mech lift, lost 2 pumps, hmnn have a look in that link of a dissected electric lift, soft rubber parts, 70 micron sock in tank alone IMO is not enough protection and why I have 10 micron filter before the lift, protects the entire system more better, and what GM should have put there to begin with.

Electric pump required for turbo 6.5 not enough delivery volume for turboed trucks from mech lift, lost 2 pumps, hmnn have a look in that link of a dissected electric lift, soft rubber parts, 70 micron sock in tank alone IMO is not enough protection and why I have 10 micron filter before the lift, protects the entire system more better, and what GM should have put there to begin with.
I wasnt tring tosay that I was going to do away with my elec lp.

My first lift pump was replaced same time as the tank. The replace ment was on off brand. I was running low on funds at the time. That 1 lasted from 12\??\05-10\??\08. This time it got a delfi. When the off brand failed the problems that I had were I couldnt really put my foot in it. When I changed the filter the lift pump wasnt doing any thing but make noise.

Also do you have any vac reading of between your pre filter and lift pump.

less than than 7" Hg at all times or I'd be setting the high vac alarm I have on it to let me know it's plugged/getting dirty.

I used a Racor 60T on mine, if not using a Racor you would have to check with the mfr of the filter element to know the restriction, I put a 60 gph rated filter on mine, not because I'd flow that much, but because it had less flow restriction than a 45 gph element.

IMO as well as several filter mfrs I consulted, 2 micron is too fine for primary filtration 20 or 10 is what you need to use in their recommendations to me for primary filtration purposes, the on engine filt for 6.5 is a 5 micron nominal and sufficient for our 2200 psi injection systems.

Dmax uses 2 micron at engine because any dirt for them at 22,000 psi injection in fuel becomes an abrasive and erodes parts fast, but even 2 micron primary for them is too fine per Wix, Stanadyne, and Baldwin filter company tech depts.

Ok new mechanical lift pump installed, Damn I had forgot just how big a pain in the ass it is to install… that damp plunger! Why did they not put the pump on top of the cam so the drive pin could fall out of the way? Rant over.

Price of mechanical pump vs electric: $19.99 USD plus tax vs. $82.99 USD. That's O'Relly prices here in NW Arkansas.

Time to replace mechanical lift pump: 2.5 hrs… fighting plunger, one handed operation due to space constraints. Real bitch.

Priming was very quick as the pump puts out lots of volume: I started off with filter out of housing so I could see the fuel coming into the bowel. It took maybe 10 seconds to fill bowl. The fuel coming into the filter housing reminded me of a very large coffee percolator. Put filter in and opened the vent on top, took maybe 10 seconds of cranking to purge air. Tightened vent and started engine in less than 5 seconds of cranking. Engine did miss for maybe 15-20 seconds and then smoothed out. Opened t handle and flooded hotplate but engine continued to run. Hose coming from t handle must be routed wrong to flood hotplate…yes?

Not sure how much volume / pressure the engine driven pump is producing, but in my estimate it’s doing more than 1.5 gallons per minute. The reason I say that is I have a low volume water pump that is putting out about the same volume. That would be 90 GPH… and this is based on the cranking RPM. Lots of fuel… Per O’Reilly the pump fits a 1989 6.2L 1 ton pickup.

Now back to my original issue, http://www.dieselplace.com/forum/showthread.php?t=287844
white or gray diesel smoke coming from exaust @ high RPM. Still having some white smoke, but not nearly as much. But still @ high RPM I get some. If you just stomp the accelerator while sitting in driveway you get lots of smoke with no load and engine is missing anytime I get white smoke. On the road the same is true, white smoke @ high RPM. Only @ high rpm. No smoke at idle or mid RPM range, only high RPM. Does not seem to matter if engine is hot or cold. This is diesel smoke, not oil or water...



What next, IP pump or timing, injectors, maybe air filter? Maybe I just pull filters and test without filters?

As you have been advise prior, you really aught to go the the 6.2 forum.

Ya, you got a 6.5 as far as displacement, but with all the mechanical characteristics of an early 6.2.

Try it, you will be pleasantly surprised, count on it...