Another Fuel/Dist Question I think

[Cole Sanger]

Took the boat out today for the second time. Fixed the other problems from last time, but had a couple of new minor one's. Of course the boat was running great on the trailer. Get out on the water and my fuel pressure takes a crap. I have two Holley 660's, and yes, a Holley electric fuel pump. I know, I know, get rid of it. If that is the problem, I will. What I was seeing was that my fuel pressure was fluctuating real bad, almost down to 0psi at one point. Tanks were full. Didn't have this problem last/first time out. I let it sit for about 10 minutes, and the pressure came back up to about 3psi. Enough to get me back to the trailer. Now for the reason I need help...I also had my Tach go crazy. It was fine at first, then started going crazy. The two problems almost came at the same time. I have everything grounded at the same point, but I thought if the ground came loose, the fuel pump would shut off completely, or atleast turn off and on. That wasn't the case, or atleast I don't think it was, couldn't really hear it with the headers and all. I was thinking clogged fuel filter, and still haven't ruled that out. Just makes me wonder with the Tach going nuts. Anyone have any ideas? Thanks in advance. Oh, before I go, I should also say that I did set up my floats since the last time out. My carbs sit sideways. I adjusted them on the trailer with the engine level. It was better on the water this time, but still seemed like they were flooding a little, just like last time out. Could it be the floats sticking? I don't think that would screw with the fuel pressure though. The gauge is on my fuel rail just before the carbs. Also, I have two aluminum fuel tanks that have a pickup tube on the top, not gravity fed like some. One last thing I just thought about, I replaced my oil pressure gauge last night because last time out it got stuck at max. Maybe I screwed with the wires on the Tach or something. Haven't been home long enough to go look.

[SmokinLowriderSS]

Bad ground. Clean that and then put in another one or 2, just as backups (to DIFFERENT points on the motor. :D ) My Taylor has 3 separate ground wires running to 3 separate places.
Mechanical fuel pump. Bad ground doesn't bother it. :D

[FASTRAT]

i agree with Smokein...add a couple more grounds & divide up the wires to them...also...GET RID of the elect pump & go to a mech...my .02 cents on the carbs...i dont care for the 660's...i could never get them to work rite...Smokein has a sgl (i believe) holley 700cfm on his & it purrssss...u might try 2 of them on urs
fastrat

[lilrick]

definitely elec. problem.

[GofastRacer]

ii dont care for the 660's...i could never get them to work rite...fastrat
The 660's work great(for carbs)with the proper modifications!..

[Unchained]

If you don't have any luck with the grounding problem look at the internal bypass in the Holley pump. It's just a basic brass plunger with a spring behind it.
They will stick in the open, closed, or in between positions. That's the source of the Holley problems.

[superdave013]

stuck floats and an elect fuel pump can make a nice engine go BOOM!
and when it does all I'm sayin is oil's HOT!!

[Craig]

If I idled a bit in the summer the pump would heat up and shut down. Let it cool and it'd fire back up. Wouldn't do it cruising. Solved the problem by going to a by-pass regulator. Like some guys said, look at the electrical. Low voltage will kill the pump.
Craig

[Cole Sanger]

Tach was easy enough. Looked under the dash this morning, and the ground wire was off. Looks like it didn't fix my fuel pump problem though. I am going to see if I can find a mechanical pump local today and hopefully this thing will be done once and for all. Thanks for all the help so far. I will post what I find. Oh, and yes, yes, I should have listened to all the people/posts about the fuel pump. Sucks, this was the second time on the water with it, and the fifth time it had been turned on. In my book, that is still brand new. Thanks again. :D

[Cole Sanger]

I didn't mention that I run 50/50 mix of Av Gas and 91. Could the lead in the Av Gas (2 grams/gallon) prematurely kill or clog an electric fuel pump/filter? Still changing to a mechanical this weekend, but thought I would ask anyway. Thanks

[Rexone]

I didn't mention that I run 50/50 mix of Av Gas and 91. Could the lead in the Av Gas (2 grams/gallon) prematurely kill or clog an electric fuel pump/filter? Still changing to a mechanical this weekend, but thought I would ask anyway. Thanks
Not likely.
Continue to check your grounds. You may have another weak point allowing only reduced voltage intermittantly to the pump. I don't like Holley electrics but your's being fairly new should not be failing (unless you have water through it, they rust easily [vanes] and this will cause low pressure and problems). Remember both paint and anodize are insulators, not conductors, as well as oily surfaces, corrosion at the battery cable ect.

[Rexone]

One way to rule out the bad ground affecting the fuel pump is to hook a volt meter on it and have someone read it while the pressure drops off. If the voltage drops off you have your problem. If not, it could still be a pump problem but not likely a elec supply problem. Is the pump making any abnormal noises when the pressure drops or is it a consistant humm?

[Cole Sanger]

That's a great idea about the DVM to it while it is running and see what I get. The headers are so loud that there is no way to tell if it is changing pitch. After reading a bunch, almost all, of the posts about bypass systems, I am pretty much sold. That and how many problems people have with the Holley electric pumps, I am sold on the mechanical pumps. I think I am just going to run to the parts store tomorrow and get a mechanical pump, throw it on there and see if that fixes my pressure problem. If it does, then I can look at getting a good pump, along with all of the fittings/lines/regulator that I will need for a bypass system. Running the bypass line back to before the pump is ok right? I don't have extra bungs to run back to the tanks, so I need an alternative. Thanks.

[sanger rat]

Here is an option. http://www.racepumps.com/

[FASTRAT]

i run the Edelbrock Hi-Po mech pump bought from Summit...n/p's ever...feeds everything i ever ran...no reg & no by-pass...ck with the boaters down in ur area (u should know who they are) 1 of them might have a spare they will give u...if not...i can find u 1 cheap/free
fastrat

[SmokinLowriderSS]

Just make sure you get a big enough mech to feed both those 660's at full howl. Would suck to be just short of capacity and get wound out only to slowly run dry. My 25 yr old fuel pump went weak in '02 and I had that problem, feeding my single 700CFM 4150.
Yea, she roars more than she humms fastrat, but she is smooth and very low-trouble. :)

[Cole Sanger]

Holy Crap!!!!
Found this when I pulled off my fuel filter. I am going to go out on a limb here and say this was my fuel pressure problem. What do you think? :rollside:
What bothers me about this is that I just had both tanks out a couple of months ago (20 gallons of gas), flushed them out and had one pin hole welded. My old fuel pump had a bunch of sand in it - came with the boat, that's why I just replaced it when I had the tanks out. There was a little in the filter back then, but nothing like what I found today. The picture is poor quality, damn digital camera, but it shows 1/3 of the crap I got out of it. Probably had three table spoons of sand/dirt/whatever.
NEW PLAN: Run the electric pump to the mechanica pump, since I just installed it, then to regulator and to carbs. I don't have to regulate it between the electric and the mechanical do I? Always the simple stuff that kills a good day on the lake.
http://www2.***boat.com/image_center/data/500/643Fuel_Filter.jpg

[paradigm shift]

Looks like you found the problem! I like the kiss solution. Keep it simple stupid. I would scrap the electric. Electric pumps do not like to suck but will push pressure well. If you wanted to you could use the electric with a low pressure switch for priming and it would also turn on if you ran low on fuel pressure as a back up pump. Just a thought.
A good mechanical pump with properly sized lines and fittings works very well. I am some what biased as that is what I run. Check out some of the known builders motors and you will see them.
Hard to tell from the picture is that varnish or do you know? Have you ran ANY additives - cleaners?

[Rexone]

CS if you continue to run the Holley electric pull the bottom plate off it and make sure it isn't full of crap. Also the screen in the inlet fitting if it has one. Filters don't always catch 100%. Also you might consider a larger filter that has some water separation / trapping capability.

[GofastRacer]

Just make sure you get a big enough mech to feed both those 660's at full howl. Would suck to be just short of capacity and get wound out only to slowly run dry. My 25 yr old fuel pump went weak in '02 and I had that problem, feeding my single 700CFM 4150.
Yea, she roars more than she humms fastrat, but she is smooth and very low-trouble. :)
Any 6 vane pump will be more than adequate for 660's or 750's, just use a bypass instead of those chicken shit Holley regulators, that is the biggest restriction!...

[Rexone]

Any 6 vane pump will be more than adequate for 660's or 750's, just use a bypass instead of those chicken shit Holley regulators, that is the biggest restriction!...
true dat!

[Cole Sanger]

Thanks for all the info. I know it's not the best for cooling the fuel or anything, but I was thinking about running a bypass back before the electric pump. That's almost 4 feet in a -8 line from the carbs. Should be ok right?
Rexone - I am using a Golan 4in fuel filter I bought from your website. It doesn't separate the water, but it is pretty big I thought. What do you recommend? Thanks again. As soon as I get all the fittings, next week, I will let you know how the third trip out goes.

[Rexone]

In inline Golans are a great filter for what they are. Filters need to be proportional and geared for the amount of crap and water "you" are dealing with though. If you're continually plugging a small filter up then my recommendation is you add a larger water separating filter on the tank side of the fuel system, like the Fram cartridge type for instance. That keeps the majority of crap out of the small filter and allows it to do its job without stopping to clean it every hour.
The fuel circulation you describe will work, you just lose the cooling effect you would get by returning it to the tank(s). It is still cooler however than a deadhead system.

[Cole Sanger]

Thanks Mike, I am hopeing that the crap in the system is gone now. This is only the second time the boat has been out in a few years. I went through the tanks a couple of months ago, and the line from the filter to carbs. I am thinking that this junk must have been in the lines from the tanks to the filter (almost 4 feet on boths sides = 8 feet of line). I will probably have to keep a close eye on it the next few trips out, but after that it should be reasonably clean. Thanks again. :)

[Rexone]

If it's old fuel line (yes even braided) it may be coming apart inside (flaking). Could be some of the debris possibly in the filter. Just an idea if you keep seeing it. Not to mention the safety problem of deterioriated fuel line. :(

[Cole Sanger]

Thanks Mike, I will keep that in mind.