So I'm replacing my worn out mechanical lift pump with the Holley "Red" electric pump. It's a beefy unit!!! However, couple of questions:

1) The inlets and outlets...are they 3/8"? Kind of pisses me off that now I have to get adaptors to plumb in and out to rubber lines...no nipple adapters?

2) How are people wiring the pumps? Relays? I don't mind just wiring a flip switch on the dash.

3) Pre-filter...is anyone running a filter BEFORE the pump?

Thanks!

When I had my holley plumbed, I used all an fittings with steel braided line.
Wired it to ignition on power with no relay.
No prefilter was used.

Everyone that I know that has tried the holley pumps have since switched. They seem to slow down after a while, or completely stop working all together.

Everyone that I know that has tried the holley pumps have since switched. They seem to slow down after a while, or completely stop working all together.

*Sigh*...I can't win. :(

Zeit,
Head over to your local Advance store, they got the 6.5 electric lift pump for around $70.00. Where I got mine about a month and half ago. You'll still need to get the GM fuel pump repair kit X 2 for about $15.00 each to get the ends. A filter before the pump is suggested, running without one voids warranty on pump. As mentioned above, I just ran the hot lead to the ignition wire on the injection pump. The pump is building pressure as your glows are cycling. Tap the key, instant start.

So I'm replacing my worn out mechanical lift pump with the Holley "Red" electric pump. It's a beefy unit!!!

Electric pump is certainly handy when it comes to bleeding fuel filters - but . . . there's not an electric pump on the market that can draw fuel as well as a mechanical pump. Mechanical pump is cheap and lasts a long time - so, at least for me - I don't see much advantage. Electric pumps are designed primarly to push fuel, not suck fuel from a distant and/or low source. They work well as boosters used along with the mechanical pump to make filter changing easier.

Personally, I won't use them. But, I live in area that uses lots of road salt and I've had many corrosion problems with externally mounted electric fuel pumps.

Mechanical pumps are designed to create high suction - which is a lot more important than any PSI figures. Electric pumps are NOT designed for it - that's why they are supposed to be mounted low, and preferrably, as close to the tank as possible. When electric pumps are OEM installed, they are usually stuck inside the tank at the bottom - or - if mounted outside - the tank is usually designed to flow fuel more easily. In fact, many auto companies - if using an externally mounted electric fuel pump, have the tank designed to provide gravity-flow of fuel as well as being as close as possible to the tank.

Take a long truck, like a 17 foot Suburban - and have it pointing up a very steep hill. If the electric pump was mounted in front, it could easily wind up being 5-6 feet higher than the fuel source - and that could cut the flow down very low - with some pumps down to nothing. With a mechanical pump, you never have that problem. For example, take a Delco EP158 that's used on some 6.5 diesel trucks. It's rated 10-14 PSI and 20 gallons per hour - but - that's when gravity fed fuel. Most GM trucks do not have gravity feed fuel - it must be lifted a foot even when the truck is on level ground. I suspect the 20 GPH electric pump, when on a long truck, and mounted up front, drops to near zero flow when climbing a steep hill.

One funny thing I did recently, by accident. I was trying to get a 91 diesel Suburban running that I bought at auction. No matter what I did, it kept getting air in the fuel - I could not bleed it out. I replaced the entire fuel line from tank to fuel pump and it still did it. I then replaced the fuel pump and it STILL did it. I finally decided this thing has some wierd problem like a fuel pickup broken high but inside the tank - or a pinhole on top where I cannot see. So, I put an outboard motorboat 5 gallon tank in back inside the Suburban, put a hole in the floor, and ran a 3/8" plastic fuel line all the way up front. Then, the fuel filter bled out fine and the 6.2 started right up and ran great. Well, I then drove it up to my top field to park this thing - with plans of stripping it sometime. I climbed a steep mountain farm-road - as steep as you can get with the Burb in 4WD low-range. Got to the top and I heard the outboard tank make a loud metallic sound. Looked back - and guess what? I forgot to open the vent-screw on the fuel cap. The suction from the mechancial fuel pump sucked the walls of the steel tank half-way in - which I found pretty damn amazing. If I'd had an electric pump, I'd never had made it up the hill.

Check out a Walboro FRB-5 I'm using on my 6.5, it is 45 gph capable 11-12 psi, more importantly it has flow thru on fail capability so a healthy IP can pull it's own fuel thru it.

As for electric vs mechanical, I don't see why one set up from the 6.5 won't work, one from a 93 6.5 pump has highest delivery of the GM factory offerings, up down sideways I've never had a problem on pulling a suction, except when the in tank sock was crudded up, or the power to the lift pump was having issues, which is why you want a flow on fail so IP cvan get you home at least, I believe but don't know for sure the DB-2 does have enough oomph to pull it's own fuel without assist of a pump, if it is already running, may be a hard or no start issue.

I believe but don't know for sure the DB-2 does have enough oomph to pull it's own fuel without assist of a pump, if it is already running, may be a hard or no start issue.

Yeah, the little vane pump in the back of the C, CB, D, DB, DC or DB2 Stanadynes can pull a lift of around 5' - 8'. Fine for most running, not very good for priming filters though - especially with a long truck. I've worked on several diesels that don't use any exra fuel pump at all - but most are gravity feed. My little Isuzu pickup truck however has no extra fuel pump - just uses the built-in vane pump in the Bosch-clone Diesel-Kiki pump -which uses pretty much the same setup as the Stanadyne. But, it's a short diesel mini-truck - so even when pointing straight up a hill, there's not much lift between the tank and engine. My diesel Chevy Chevette is set up the same way with no fuel pump. A 17' long Suburban or truck would cause a longer run and potential problems.

In regard to electrics and allowing fuel to be pulled through them? I never gave it much thought, but at least years back, it was assumed they all did it. Back in the 60s and 70s, electric pumps were often installed as boosters rather then stand-alone units and it was assumed fuel could be pulled through them (not counting the little pulse-pumps). In regard to a 6.5 turbo, the injection pump puts out a max. delivery of 15 GPH, so there not an awful lot of flow needed anyway. A J-code 6.2 only pumps a max of 11 GPH.

No offense, but where the hell were you guys a couple of weeks ago? I have the pump at my house...I already bought it! Everyone posting in my "won't start" thread was talking about electric pumps.

Should I return the Holley?

Sorry about not being around, but I was deer hunting at 10,000 feet in the Rockies:D No cell phone and no computer.

As JD said, use a stock mechanical pump for the best reliability.

Out of town in Houston dealing with my own won't start issues, see snot in my stocking thread over in 6.5 forum

So I'm replacing my worn out mechanical lift pump with the Holley "Red" electric pump. It's a beefy unit!!! However, couple of questions:

1) The inlets and outlets...are they 3/8"? Kind of pisses me off that now I have to get adaptors to plumb in and out to rubber lines...no nipple adapters?

2) How are people wiring the pumps? Relays? I don't mind just wiring a flip switch on the dash.

3) Pre-filter...is anyone running a filter BEFORE the pump?

Thanks!

Yes filter before the lift pump 30 or 10 micron (I run with a 10), safest way is to wire it from a relay controlled by a OPS, that way in event of a crash when the OPS loses pressure, the lift pump loses power also and in event you forget to switch off ignition or the toggle switch or worst case get knocked out yourself, you aren't supplying a potential fire with pressurized fuel.

Forget it, peeps. I already returned the Holley and bought the mechanical lift pump. It'll be here tomorrow.

Thanks for all the guidance.

Gaddamnit...new mechanical lift pump does nothing. It still won't start unless it's primed with WD-40 to get it to kick. It ran great after priming it last night, and even started again after an hour and a half sitting! (engine was still warm.) This morning, however...nothing :(

I'm wondering if air is getting into the system, but if it is with no petcock on the fuel filter how I'm going to bleed air from the system. I'll go check the stickies again...

Gaddamnit...new mechanical lift pump does nothing. It still won't start unless it's primed with WD-40 to get it to kick. It ran great after priming it last night, and even started again after an hour and a half sitting! (engine was still warm.) This morning, however...nothing :(

I'm wondering if air is getting into the system, but if it is with no petcock on the fuel filter how I'm going to bleed air from the system. I'll go check the stickies again...

I didn't read all your posts and I'm not sure why you don't have a bleeder on your filter assembly. But, you have to get all air out - period. If air bubbles keep getting into the fuel that goes to the injection pump - it will not be able to bleed itself out. Even just a little air will screw everything up.

I just had a bad experience with a 91 diesel Suburban. I say "bad" because I should of spent some time diagnosing its problem. But, since I've been working on diesels 40 years - I just guessed on a few things and thought I could fix it fast. My "fast fixes" did not work.

Long story short. I bought an auction 91 diesel Suburban from a school. It was fine when parked - but hadn't been started in at least two years. I put batteries into it - and did nothing else - and it started right up - ran great for around 30 seconds - and then died. Would not start again - wouldn't even try.

So, figuring it was a rusted-out fuel line back by the tank - which is typical - I ran a rubber hose - all the way from the top of the tank to the fuel pump. Tried to bleed it out - and STILL had air. So, I got a little pissed off - and put another fuel pump on it. Same problem. Now what? Actually - I still don't know what the problem is - but it has to be something broken - or rusted at the fuel tank. I finally put a 5 gallon outboard motor tank on the floor inside the Burb. Hooked it with a rubber hose to the fuel pump. Fuel bled out fine this time and it started right up and runs great. I'm not worried about whatever the problem is - because I only bought this thing to strip - but wanted to drive it first and check out the trans, engine, and 4WD first.

Is it possible/advisable to run an electrical pump in series with the mechanical one?

Last week I installed an aftermarket fuel filter/water separator (Wix 33123) in line before the stock "brick" filter to deal with a persistent WIF light. Now I`m pretty sure the water sensor is faulty, and I just unplugged it for now.

Anyway, the engine seems to be running more smoothly with the extra filter (Any idea why that might happen?), but I might have lost a little power --- or it`s just me. I want to keep the mechanical pump, so I`m wondering if it`s a good idea to add an electrical pump in between the aftermarket and the stock filter.

The Walbro pump TD mentions looks like a good choice; but 11--12 PSI, isn`t that eventually too much pressure to the IP?

won't be too much for the IP, but it will be too much for the box filter and mech lift pump. you'll wind up with leaks everyehere. if you want to use that pump get yourself an inline reducer. try to keep the PSI around 4-6. make sure you age getting at least 30GPH.

Hmmm ... I can see that the brick filter might start leaking easily, but the mechanical pump would be on the suction side of the electrical one. All filters are behind the pumps, the electrical pump would be behind the first filter. How would that make the mechanical pump leak?

I won`t mind replacing the brick filter with a spin-on type filter. The water sensor is probably broken, and I might get a fuel pressure gauge which would obsolete the pressure switch of the brick filter. I drain water from time to time anyway ...

Replacing the brick filter would mean to upgrade to the spin-on filter setup used on earlier models. Those were fine with the mechanical pump only, so I won`t need an electrical one. I think I`d like that even better, and it`d probably be cheaper.

So what would I use for a fuel filter? For what particle size are the stock filters (brick and spin-on) rated? 5 micron?

i haven't found a 12v pump that will pull all the way from the tank when mounted in the engine compartment. i have mounted all my pumps on the frame by the tank. i guess thats why my filter and mech pump started leaking.

i am using a 5 micron ramco screw type filter w/heater and water seperator.