New option for fuel pump replacement

[scottfab]

Originally Posted by TFENT

I called a resource and a whole new AC Delco sending unit with 2 Delphi pumps is only $275. I am thinking of just getting the new unit...

Thoughts???

Not a bad idea. Having one whole assembly as a spare is what I'm thinking now. I'd worry about all the mods cracking and falling apart and/or multiple splices adding to intermittent issues. And yet this could be a good alternative should it hold up for a few years.

[Blue Flame Restorations]

The modification to the fuel pump holsters was a simple relief cut and will not compromise the ability to hold the pumps. The holsters will outlast the pumps. No problem.

NOTE: The relief cut is not the entire length of the holster. I only cut it near the bottom where the pump would not fully seat.

[VetteMed]

Originally Posted by Blue Flame Restorations

The modification to the fuel pump holsters was a simple relief cut and will not compromise the ability to hold the pumps. The holsters will outlast the pumps. No problem.

My thoughts exactly. Much ado about nothing.

[tomtom72]

I did this "mod" at 17 yrs and about 33k miles. My OE pumps were just a bit tired showing on the low side of the FSM PSI spec spread. I now have 55k miles so figure about 22k miles and 5 yrs worth of use, and the only issue I have had was one of the factory plastic clamps cracked. The holders for the pumps are in great condition as I just looked at them the other day when I pulled it out to check the screw clamps I used to replace the OE plastic clamps.

I know this sounds a bit stupid, but I could actually feel the difference from my original BG pumps and the new ones when I get into the secondaries. My OEM pumps tested right at 46 PSI with the KOEO test, now the Bosch pumps still test at 55 - 54 PSI.

I should mention this as a fwiw. When I bought the Bosch pumps they were over or right around $100.00 each. I looked them up like a year ago and the price is almost 1/2 now...unless I made a mistake with the part numbers because you can't look them up by application. I just wonder why they are less now than back when I bought them?


Tom

[VetteMed]

Originally Posted by tomtom72

I did this "mod" at 17 yrs and about 33k miles. My OE pumps were just a bit tired showing on the low side of the FSM PSI spec spread. I now have 55k miles so figure about 22k miles and 5 yrs worth of use, and the only issue I have had was one of the factory plastic clamps cracked. The holders for the pumps are in great condition as I just looked at them the other day when I pulled it out to check the screw clamps I used to replace the OE plastic clamps.

I know this sounds a bit stupid, but I could actually feel the difference from my original BG pumps and the new ones when I get into the secondaries. My OEM pumps tested right at 46 PSI with the KOEO test, now the Bosch pumps still test at 55 - 54 PSI.

I should mention this as a fwiw. When I bought the Bosch pumps they were over or right around $100.00 each. I looked them up like a year ago and the price is almost 1/2 now...unless I made a mistake with the part numbers because you can't look them up by application. I just wonder why they are less now than back when I bought them?


Tom

Tom, is it possible you looked up the price of a Bosch standard roller-vane type pump rather than the turbine pump? I remember paying around 90-100 each as well, about 3 years ago with my red car, and again 2 years ago with my current Z.

[scottfab]

Originally Posted by Blue Flame Restorations

The modification to the fuel pump holsters was a simple relief cut and will not compromise the ability to hold the pumps. The holsters will outlast the pumps. No problem.

I really hope you're right for all our sake. I mean if it works great but if the only remaining side cracks under the remaining pressure of the oversize pump them ugh. Know what I mean? BTW I would have used a forstner bit to widen the hole rather that put a slit in the holder.

I'm all in favor of improvements toward reliability. I've done it myself on a lot of the systems. As I said in an earlier post, time is the ultimate test as per reliability.

While we're at it though, I think the BS about "pulsing" fuel by the old pumps is an old ploy by sales folks to get you to by something. In this case something that does not fit.

I've taken two failed pumps apart. The failures have to do with "sucking air". The contacts fry very easily if a pump is run in open air at any time. Also there is absolutely no mechanism of "pulsing" the fuel in the our system. The primary pump is on all the time. The fuel system is a closed loop that returns unused fuel back to the tank. Now on my Explorer it's different. The pump is the same type as the vett but the electronics do in fact "pulse" the fuel and there is a device inline that absorbs the pressure pulses. Our ZR-1s have a regulator that drops the pressure to the rail if too high. Whole different concept than the systems (like the explorer) that regulate by turning on and off (pulsing). Even the name of the device is different on the pulsing systems. They're not called "fuel regulators". (can't think of the name right now)

Again the need to use a "turbine" fuel pump aside, I honestly hope your mod holds up. I'd declare it a success if in two years there is no cracking. But then you'd have to take it out and look either by a pump failure or just to "look see".

[VetteMed]

Nobody is holding gun to your head. Those of us who have done this mod are happy with it. If you're uncomfortable with it, it's as easy as just not doing it.

Originally Posted by scottfab

I really hope you're right for all our sake. I mean if it works great but if the only remaining side cracks under the remaining pressure of the oversize pump them ugh. Know what I mean? BTW I would have used a forstner bit to widen the hole rather that put a slit in the holder.

I'm all in favor of improvements toward reliability. I've done it myself on a lot of the systems. As I said in an earlier post, time is the ultimate test as per reliability.

While we're at it though, I think the BS about "pulsing" fuel by the old pumps is an old ploy by sales folks to get you to by something. In this case something that does not fit.

I've taken two failed pumps apart. The failures have to do with "sucking air". The contacts fry very easily if a pump is run in open air at any time. Also there is absolutely no mechanism of "pulsing" the fuel in the our system. The primary pump is on all the time. The fuel system is a closed loop that returns unused fuel back to the tank. Now on my Explorer it's different. The pump is the same type as the vett but the electronics do in fact "pulse" the fuel and there is a device inline that absorbs the pressure pulses. Our ZR-1s have a regulator that drops the pressure to the rail if too high. Whole different concept than the systems (like the explorer) that regulate by turning on and off (pulsing). Even the name of the device is different on the pulsing systems. They're not called "fuel regulators". (can't think of the name right now)

Again the need to use a "turbine" fuel pump aside, I honestly hope your mod holds up. I'd declare it a success if in two years there is no cracking. But then you'd have to take it out and look either by a pump failure or just to "look see".

[scottfab]

[QUOTE=tomtom72;145157]I did this "mod" at 17 yrs and about 33k miles. My OE pumps were just a bit tired showing on the low side of the FSM PSI spec spread. I now have 55k miles so figure about 22k miles and 5 yrs worth of use, and the only issue I have had was one of the factory plastic clamps cracked. The holders for the pumps are in great condition as I just looked at them the other day when I pulled it out to check the screw clamps I used to replace the OE plastic clamps.
/QUOTE]

You cut a slit on the side of each pump holder? And that was at something called "17 yrs" ?
And you are now at year what?
Oh wait I see, 5yrs !!!
Ok maybe this mod has more clock time then I thought. That's different then.
I wish that would have been stated.

[scottfab]

Originally Posted by VetteMed

Nobody is holding gun to your head. Those of us who have done this mod are happy with it. If you're uncomfortable with it, it's as easy as just not doing it.

Ah so you've done this mod too? I mean the cutting a slit down the side of the holder? How long ago?
That's an excellent and astute observation though. Why didn't I think of that.
I don't have to do the mod. Gee thanks.

[VetteMed]

Originally Posted by scottfab

Ah so you've done this mod too? I mean the cutting a slit down the side of the holder? How long ago?
That's an excellent and astute observation though. Why didn't I think of that.
I don't have to do the mod. Gee thanks.

My other astute observation is that you seem to argue about stuff just for the sake of arguing. There's no evidence thus far that this modification is in any way compromising the reliability of the fuel delivery system.

I've been driving my ZR-1 daily for ~2 years, 11K miles, with this mod, with no problems. I pulled the assembly out about 3k miles ago and everything looked as it did the day I installed it.