Should I change to an electric fuel pump?

[The_Handier_Man1]

From: wrayye  (Original Message)
Sent: 8/8/2001 1:11 AM

I own a 1972 chieftan. My problem is that I want an electric fuel pump installed.  I know that I have read posts that other people installed electric fuel pumps and were happy with the results. The mechanic that is working on my home thinks I need to stick with a manual one. He said I would be opening up a can of worms because I would need to have a regulator installed and I would have problems keeping enough pressure. Also the fuel pump would flood the motor and I would get stranded somewhere.



I would keep the mechanical pump, replace it if broken, and add if you are still concerned about the fuel pump breaking then install an electric one inline w/ your biggest gas tank. With this set up you can simply flip a switch and get the fuel flowing again and be on your way. I had this set up on my bronco and it worked fine w/ no problems being inline with the fuel system and still running a mechanical pump. It's basically a fail proof system.  dave1210

--------------------------------------------------------------------------------


I guess I'm going to have to be the lone distentor here.
Our 1972 Cheftian has been on many trips over the Rocky Mountains. Invariably we head over Monarche pass at noon, or 1pm, when the pavement is hottest. The top of the pass is something like 10,000 or higher. Everyone in our group always had issues. (6 motorhomes, 3 winne's,  and various others) Everyone was vapor locking.

My father put two high performance electric fuel pumps in, one at each tank, and a booster pump after the diverter for more volume. We would have ended up with about 15 psi at the carb that way... far too much. An adjustable pressure regulator near the carb reduces it to 7 psi.. The return path from the regulator goes through another divertor back to the tanks.

The beauty of this system is two fold. First, the fuel is push, under pressure, to the carb which raises it's boiling point. Pulling to the engine, under vaccum from the mechanical pump, lowers the boiling point of the fuel, promoting vapor lock. Secondly, because the fuel is always circulating, like in an fuel injection type system, there is always cool fuel in the lines. Cool fuel doesn't boil.

We went through cool cans full of ice, and heat shields, driving with the doghouse off, and others, before this system, nothing worked. This system works like a champ and, I never had a problem after that. The original fuel pump is long gone, blocked off with a plate.    Bigfoot

--------------------------------------------------------------------------------


'79, 23' minnie.440 dodge.  Fuel starved, would die under accelleration.  Shop replaced fuel pump and edlebrock carb twice, filters, blah blah blah. Didnt help. I added the 100 dollar electric (or so) pump from napa, (they stock 2 models, get the good one)  Put in the oil pressure cutoff switch.  Mounted it inline just where the fuel line meets frame by gas tank.  Left the mechanical pump in place.  I have never vapor locked or fuel starved since.  The fellas at napa said they've sold the fix to countless MH owners and never a complaint.  Total with pump, hose, clamps wires, oil pressure unit and plumbing came to 130 bux total.  Carl   (cchetlan)

--------------------------------------------------------------------------------


I have a '73 Indian and we couldn't for the life of us get enough fuel into the carb. We changed over to eletric pumps and it runs like a charm back and forth to Lookout Mountain.    demented20

--------------------------------------------------------------------------------


Something not mentioned so far about fuel problems is the metal fuel lines themselves, the ones from the tank to the pump. They can accumulate silt and crud that will make the inside diameter effectively tiny - can happen where the line is horizontal or has a slight dip, from sitting for long periods. Replacing the rubber hoses eliminates the crud that was inside them only. The metal lines themselves can also be replaced of course, but with more trouble. Because of the route those metal fuel lines ran, my Winny really needed heat shielding, after which no more vapor lock, using the engine mounted mechanical pump. On my 1950 F1 I had to clean out the metal lines: I whacked the lines lightly with a small hammer, and got a lot of crud out - after I filled the line with the solvent acetone and let it soak for a day.
And as usual, I recommend getting a fuel pressure gauge to look at, it will tell you when your fuel filter needs replacement. I carry many spares, but not a spare fuel pump, cause I replaced it in April of this year, but when it is 7 or 8 years old I might begin to carry a spare. denison



From: rshaw500
Sent: 12/12/2003 12:52 PM

When I had a problem with my 79 Brave I went in search of an electric fuel pump.   Believe it or not I was told that there are two models.   One is a puller and the other a pusher.   They say that you must mount the pusher as close to the gas tank as possible and the puller you can mount anywhere.   I found this to be true because I bought one and mounted it where the old fuel pump was up front.   It would not pull the gas to the carb.   I then mounted it in the rear near the fuel pump and it worked great.   Make sure that when you hook them up to the twelve volt that they are hooked so that they shut off with the key.
Rick



From: rshaw500
Sent: 12/12/2003 4:46 PM

Sorry,
I meant to say that I mounted the electric fuel pump in the rear close to the Gas Tank.
Rick



From: UluzYarx
Sent: 2/22/2004 6:26 PM

If you can take responsibility for your mistakes fit an electric pump.
If you can't, then fit the mechanical one.

If you fit a regulator, you are unlikely to get flooded.
If you do get flooded - disconnect the electric pump - let the petrol evaporate - crank the engine over - reconnect the electric pump - drive home - tricky to do with a mechanical pump.

Me, I'd get a more cheerful mechanic at the same time. - Dave



From: Im-still-Lefty
Sent: 2/22/2004 11:43 PM

There's nothing "tricky" about clearing a flooded engine equipped with a mechanical fuel pump. Just hold the accelerator pedal to the floor and turn the engine over. Lefty



From: UluzYarx
Sent: 2/23/2004 5:57 PM

Hey come n Lefty, your pulling my plonker with this one aren't you?
~
You knew it was the "switching off the pump" bit that was tricky on a mechanical pump and you just wanted to see if I'd bite didn't you?
~
Nice one - all the best - Dave

[Chief Crazy Canoe]

While a newbie to the forum - I've gotta ask.  What model of electric fuel pumps are you guys buying??

Living at 6,000 and driving over the passes in Colorado on every one of our planned travels - I'm leaning towards the electric fuel pump and going with a fuel injection system in lieu of the Holley Carb on the 413. 

The regulator at 7psi right before the carb sounds pretty decent - having a high-pressure divert/return loop going back to the tank sounds right - but how did you do that?? 

[khantroll]

Almost any universal hot rod fuel pump should work. Something like this:

http://www.summitracing.com/parts/sum-g3136-1/overview/

and you'll also need one of these:

http://www.summitracing.com/parts/sum-402035/overview/make/dodge

Now, as far as a fuel return, it depends. If you are converting to fuel injection, then the fuel injection parts should already be plumbed for a return line. As for a return line on a carb, the most common way is to use a pass-through fuel pressure regulator; most have a return line connection available.

Like this:

http://www.summitracing.com/parts/hly-12-803bp

I hope that helps!

[MotorPro]

If you are using fuel injection then you need a completely diferant pump from the one you need for a carb.  Carbs need a max of 6 PSI While F.I. needs a Min. of 30 to 60 PSI depending on the brand.

[khantroll]

MotorPro is correct, and I should have specified that. D:oH!

A pump like the one I linked to is fine for carbed engines, but fuel injection generally requires higher pressure at the pump; holley red/blue pumps come to mind

[Chief Crazy Canoe]

Awesome insights & thanks for the links.  I'm still on the fence with the TBI/EFI setups, simply based on their cost but there's improvements to be had with them no doubt!

Yes, pedal response is improved as well as instant starts and chokeless cold idle. Fuel effiency - uh er...."Fuel consumption rate" is we should be calling it - as "fuel efficiency" has no place in the classic RV world with these 40+ y/o drivetrains.  My D24 was consuming fuel at a rate of 457ml/min at 58mph - that is, if my "mental math" while driving conversions are correct.

At that burn rate it is laughable to call anything efficient - unless we're discussing the efficiency of the pathway from the tank to the demon of fuel consumption under the doghouse

[acenjason]

Be careful that your electric pump doesn't exceed the psi of the mechanical pump. If the rubber diaphragm bursts from high psi you get fuel pumping into the crank case. Also, I live in the high rockies. The folks above might have had problems at high altitude because in order to operate properly at high altitude carb adjustments need to be made. I had to switch metering rods and jets in my edellbrock 4 barrel. Lean out the mixture. My beloved Winny runs much better at 11000 feet now;)

[khantroll]

I am right there with you on the fence Chief. While I actually have (I think) worked out a low buck TB I setup for these engines, I am not sure the benefits are worth it. Yeah, fuel consumption is possibly lowered, and acceleration improved, and no carb adjustments. The flip side is all the man hours to get it working.

That is outside the scope of the thread, though, so feel free to PM or bump a fuel injection thread to discuss that.

Ace, just for clarity, which diaphragm are you referring to?

[Oz]

...so feel free to PM or bump a fuel injection thread to discuss that.

Best of those options would be to discuss it on the existing topics about fuel injection. 

That allows everyone else to benefit from it. 

http://www.classicwinnebagos.com/forum/index.php/topic,3876.msg10614.html#msg10614
http://www.classicwinnebagos.com/forum/index.php/topic,6206.msg25047.html#msg25047

Back to electric fuel pumps...

[acenjason]

The rubber diaphragm is in the engine mounted mechanical fuel pump. As the pump works the diaphragm flexes and allows the pump to move fuel. The diaphragm is exposed to the crank case where the small armature pokes into the motor. Or it is on my 440. Adding to much pressure from electronic pumps further back can rupture the diaphragm and push fuel into the crank case. I changed my pump before I changed my metering rods and jets because I was getting fuel in my crank case. I am now fuel free in my oil thank goodness. Any, that's the diaphragm I meant.        

[khantroll]

Glad you got it fixed      I had to ask for clarification, because I was talking about getting rid of the mechanical pump all together, and so the only diaphragm would be in the electric pump.  So I was like..... Hm? .....   

[TripleJ]

My 85 came equipped from HR with a holley blue. They are a 40 year old design, rock solid and copied by just about everybody today.

I removed mine thinking it had failed, but it was the wiring and not the pump.

If I were going to remove my mechanical pump and go to a new electric, I would go with either a holley red or blue and the holley 803BP fuel pressure regulator and place the pump at the tank and the regulator right next to the carb(requiring a fuel return line). This is almost a guarantee of no "vapor lock" or fuel feed problems, plus both units are rebuildable.

[73dodgeTitan]

Holley red here and loving it.

[PwrWgnWalt]

A couple of questions about experiences of those using the Holley Red Fuel Pump (or similar type pumps with output specs of around 95-110 gph and 7 psi):

1) Are you using a fuel pressure regulator, or just going straight to the carb?  How's that working out?
2) Are you using it in tandem (along with) a manual fuel pump, or the electric pump by itself?
3) If you have dual gas tanks, where are you mounting the electric pump - just downstream of the tank selector valve or ? 


Thanks for the answers to the above, and any other feedback you can provide on your experiences using an electric fuel pump!


- Walt

[legomybago]

1) If you dont have a fuel return line built into the system (which I think you don't), you need to run a regulator for sure.
2) Choose one or the other if no fuel return in the system. Not electric and manual together due to risk of diaghram in the manual pump bursting, and also creates more work for the manual pump to try and pull fuel through the electric pump when it's not in use.
3) Mount the electric pump as close as you can to your fuel tanks. That may mean running all new fuel line. Do not mount electric fuel pump in or close to the engine compartment, these pumps are built to push fuel, not pull fuel.

[ibdilbert01]

We just installed one of these today in place of a mechanical on my dodge 413. 

http://www.summitracing.com/parts/crt-p4594/overview/   (Carter Rotary Vane, 8psi, 72gph)

Was a spur of the moment decision as the mechanical fuel pump (only a year old) failed and I have a camp site reserved with friends this weekend.    If it wasn't given to me, I probably would of just stuck a new mechanical back on it.   Now that I see the difference, not sure I'll ever use a mechanical pump again.   Turn the key to the on position, wait a few seconds and the bowl is guaranteed to be full and ready to start.   

[TripleJ]

1) If I was changing anything about the factory fuel system I would for sure be installing a regulator. First due to normal manufacturing variations. Second, if you arent certain what fuel pressure you are running, you open yourself up to misdiagnosing all kinds of issues that could possibly be caused by high or low pressure.  For instance I just learned that edelbrock isnt kidding when they "recommend" no more than 5.5 PSI for their 1411 model carb.

2) If you are installing something like a Holley blue, there is no reason to have any other pumps in the system. I know some people have installed them along with a mechanical, and if it works for them thats great. Mine came from HR with a blue in line with the mechanical pump.

3) As has been said, as close to the tanks as possible

[circleD]

TripleJ, what happens if you run over 5.5 psi on the 1411? I only have a mechanical pump and hope it isn't pushing more than needed.

[DaveVA78Chieftain]

High pressure on any carburetor results in pushing the float needle off it's seat flooding the carb/engine.

Dave

[PwrWgnWalt]

Thanks for all the input everyone.   
Correct - no fuel return line on my Dodge...

So here's a couple more questions:

1)  So if I have a main fuel tank at the rear of the MH, and an auxiliary tank behind the passenger
     -side front wheel, do I need two (2) electric fuel pumps (each mounted close to the tank)?


2) The Holley Blue specs at 110 gph @ 14 psi (70 gph @ 9 psi), and
     the Holley Red specs at   97 gph @   7 psi (67 gph @ 5 psi)...

So when using a regulator set to, say 5.5 psi (for the Edelbrock 1411), is the extra 'oomph' of the Blue just going to waste?  Am I missing something with this that might make the Blue better than the Red?  (from what I see, it appears the Red is better for a carbureted MH engine)

Also - what about fuel starvation at high loads?  (if extrapolated, by the time the Blue pump gets to 5.5 psi, it might be flowing 45 gph - I would assume that's enough for the 440 running hard)

Thanks again!

[legomybago]

We run the RED pump. I purchased it used from Froggy, works great for our thirsty 454.

[TripleJ]

CircleD I Hvae a new 1411 on my engine and a new mechanical pump. I was having trouble getting it to run right, and reading that some people were running them problem free right out of the box.  Long story short I finally stuck an inline fuel pressure gauge and found that the mech pump was running as high as 7-9 psi. Got a holley regulator set to 5psi and my stumbling and intermittent crappy running went away. I could go further into detail but Ill save it for another topic.

pwrwgnwalt a blue will feed a 500 hp engine MAKING 500 hp.  These old big blocks will not come anywhere close. Finding the gph numbers is for somebody with more time on their hands than I have