Electric fuel pump on IDI????

[ttman4]

I notice a lot of Holly Red fuel pumps being used on the IDI's.
Question #1: Anybody know what press & Vol the mechanical 7.3 pump puts out? Or is needed to supply the IP? I seem to recall that it was rated @ 9-11 psi, but can't find it now. (from a past dream of mine...??) I recall that to test it, it needed to draw about 12 in Hg (vacumn) on the suction side.

Q#2: If an electric pump of hi vol/ pressure is installed, will this still work, or will a restrictor have to be installed. Will the IP still be able to handle the excess & just return it to the tank?

Reason I ask is that I have a too small electric pump currently in place & need a bigger one. I left my mechanical pump in place, disconnected it & looped a hose round from the inlet to the outlet to keep it sealed & trash out.
I have access (nearly free) to a Holly # 12-706-1 pump, but looking on the E-net at Performance Center.com they say:
<The high volume output of this pump makes it the natural choice for racers who will settle for nothing but the best. This pump features a gerotor pump design which is extremely efficient and quiet. Fuel pressure is pre-set at 15 PSI and both a pressure regulator and 3/8in return line to the fuel tank are required. This is a racing fuel pump and is not designed for continuous use.>

This same site above says about the Holly Red: <This externally mounted fuel pump is designed to work with stock or mildly modified engines. Pressure is pre-set to 7 PSI and a regulator is not required. This pump features a simple, yet rugged rotor and vane design.

Anyway, someone got some thoughts? I gotta do something different soon.......& I'm a cheap tightwad!!! :Sly
I run WVO, WMO, buttermilk, Gatoraid, bulls@*t, diet cola, & even diesel when I have my siphon hose with me after sundown....
Thanks
James

 

[Agnem]

Maybe you could get the free Holley, and sell it on ebay and buy a red one? :Sly

 

[Dambnicetruck]

Where do you get the red ones?

 

[ttman4]

Well my "near free" Holly pump got "gived away" to somebody else anyway. If I had got it I would have had to do about 3 hours welding for the guy. I didn't have anything against the 3 hours in my own sweet time, but this little project turned into one of those "needing it yesterday" (just like I don't have anything to do) & "you said" & other little attitude thingies.......so I just passed on it.
Mel, since you mentioned EBay, I looked round on there & saw one like it item # 8011284539 bid up at $41 + about $17 frt.

Oh well, I'll just keep looking. Hooked my mechanical back up last night. (got colder'n h**l round here last night& gonna get colder tonight!)

 

[highest_vision]

You can get a holley red at places like here for a decent price. There is also a marine version, don't know that it is worth an extra $20 though.
James

 

[Agnem]

Another source for a good electric pump may be (and I'm unsure of the year, but I can definitely say an 87) F-150's and Bronco's with an EFI engine. My Bronco has a factory electric fuel pump, mounted on the frame just below the drivers feet, and while I haven't driven it over the road yet, it appears to have all the qualities we like in a fuel pump.

 

[Full Monte]

I left my mechanical pump in place, disconnected it & looped a hose round from the inlet to the outlet to keep it sealed & trash out.

Anyway, someone got some thoughts? I gotta do something different soon.......& I'm a cheap tightwad!!! :Sly

While your mechanical pump is installed, it will be operating. You may think you are saving $9 on a large-block Chevy plate, but it may cost you a lot more when the pump arm falls off the pump inside your oil sump. I know...it happened to me.

 

[Scott]

Fuel system
Next check for fuel delivery through the fuel filter. On 6.9 engines this is checked at the 3/16" hose barb on the fuel filter outlet elbow, and on 7.3 at the fuel filter orifice/return line fitting or restricted filter sensor port. If checking either at the filter return line fitting, plug the return hose. Fuel pressure here should be 1 psi minimum at idle. Lift pump pressure is taken at the fuel filter bleed schrader port and should be 2 psi minimum at idle. Fuel volume is taken at the same point and should be at least one pint in 30 seconds at idle. Inspect the fuel taken during the volume test for signs of water or contamination.
If the engine won't start, these specs may be lower as idle speed is 675 RPM and cranking speed will be less.

Fuel supply and return line restriction is normally tested with the engine at 3300 RPM. For supply restriction a vacuum gauge is tee'd into the lift pump inlet hose and should read less than 6 in/Hg at 3300 RPM. For a return line restriction a pressure gauge is tee'd into the hose running from the rear of the engine. This should read less than 2 psi at 3300 RPM. But a return line restriction can also be detected by installing a clear hose in place of the return line hose at the fuel filter. Watch the flow of fuel while cranking and if it flows towards the filter, inspect the fuel return circuit.

Installing a clear line at the filter return can also be used to detect air intrusion into the fuel supply system if this is suspected, although at this point the symptom would most likely be a stall after starting followed by a hard start, in which case by changing the location of the clear line you can pin point the area of the air leak. If air is getting into the injection pump, this would cause hard start concern. A clear line can be installed at the injection pump outlet to detect this.
If the concern were a rough idle, the clear lines can be used to detect aeration of the fuel. Install the lines and start the engine. Run the engine at 3000 RMP for 2 minutes, then watch the clear lines for signs of air. Some bubbles less than 1/16" is normal, but if the bubbles are larger, constant, or if the fuel appears to foam, there is air being pulled into the supply system.

To check the transfer pump pressure inside the injection pump, a special adapter which replaces the transfer pump cover lock screw and attaches to a 160 psi gauge (the cover lock block has to be in place). Transfer pump pressure is taken at 3300 RPM and should be 90-110 psi for 6.9; 90-120 psi for 7.3.
If the engine won't start, all other checks are normal, and there is no air inside the injection pump, chances are the transfer pump is not producing enough pressure to start the engine. This can be checked by opening one or more injector lines while cranking. If no fuel is reaching the injectors, suspect an internal injection pump problem.

This info is from dieselman page. Hope this helps you in the direction you are going.

 

[82F100SWB]

My Bronco has a factory electric fuel pump, mounted on the frame just below the drivers feet, and while I haven't driven it over the road yet, it appears to have all the qualities we like in a fuel pump.

I think you may run into issues with that pump...
Your bronco actually has 2 pumps, one in tank, low pressure, and that high pressure pump(which has no suction) on the frame rail. We're talking EFI fuel pressures here, so, regulated at 40 odd psi(55 with a 300 I-6.) Ford Ran that system on the EFI trucks until 89, when they switched to a high pressure in tank setup.
My carbed 460 truck(86) has the "hot fuel handling system" which is the low pressure pump in the tank from the EFI setup, with an orafice valve at the carb and a return line, it basicly uses the needle and seat in the carb as pressure regulation, and always is returning fuel to the tank to prevent vapour lock.
If anything, the low pressure in tank pump may be useable. I can't say how friendly it is with #2 though, I've never tried one with diesel.

 

[Agnem]

Your the second person that has tried to tell me that. I'm taking your comments into consideration, as I investigate the in tank pump theory, but I can tell you that I don't believe (if it is really there) that I am energizing it, and I did run this electric pump until it emptied the tank of all it's fuel, and then once it stopped pumping, I was able to put diesel in it, and it re-primed itself. I don't want to divert this thread, so I'll limit my comments, but I can see that the pump presure is not enough to blow up anything, so far.

 

[ttman4]

It seems most everyone is running the Holly Red Fuel pumps. I wonder if a Holly Blue would work on one of these IDI. The Red's are cheaper, but the Blues come with a pressure regulator, so cost wise they are about the same, at least on Summit web site. http://store.summitracing.com/ The Blue's pump more volumn & pressure. But I may not need a lot of extra pressure??? And would I be creating myself a problem that the return lines couldn't handle??? All I need next is a return line blow off & hose everything down....be rolling down the road sitting on a fireball before I noticed & stopped!!!
Reason I'm asking is that I been looking round like on E-Bay. Sometimes the Blue might be picked up on the cheap.....or I could just wait & find a Red. Theeenn, there are the Holly Black, & all other kinds, some cheap if you can catch 'em just right.

Either way, I'm back to running my mechanical since cold weather hit & some of my WVO & other secret concoctions don't get along always. That cheesey small electric I used thru the summer don't cut it in cool weather even though I got heated tanks & lines.
I had just bypassed & plugged off the lines to my mechanical, but after Full Monte tells of learning the hard way about the mechanical pump arm falling off & falling in the sump, I got a chill thru my heart & decided to "pull it & plate it" soon as I get a good electrical pump back on.
BTW, my mechanical went out last year & had probably 350K-400K on it.
James

 

[Agnem]

I recently experimented with running a Ford Bronco factory fuel pump for a 351W with EFI. I don't know what the stock presure rating of this pump is, but I've been told it is pretty high. When I would turn the pump on, I could hear the presure building up in the system, and watch the lines swell. The pump would start to bog down, and it sounded like it was straining. This advances the timing in the injection pump significantly, and creates a stability problem at various RPM's. A pump that creates higher presure than what is needed, is simply working harder than a pump that is sized correctly, so while you might save money now, it would be hard to say if the pump would last as long, or if it wouldn't be prone to costing you extra money in uneeded repairs.