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ROMPERSTOMPER

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Tech Questions for efi and fuel system issues
« on: February 04, 2010, 03:17:38 PM »
 Been a while sice Ive posted. I finally finished the romperstomper and took it out for the first run at the Top papp memorial. It ran great. Since I lost the tune I had on the dyno I had to start all over on the water because I didnt want to take the motor back out. I got a pretty good base tune but it still needs a lot more tunning.  When I rigged this boat I spared no expense on the cooling system and fuel system using all an hoses and hose ends. My first question is after about 6 to 8 high speed laps around elsonore one fuel tank ran dry and the other was about half full the passenger side ran out first. the boat would not run with one tank empty? good thing I was close to the dock when it ran out. so I refilled both tanks and boat fired right up. shortly after at a 5 to 10 mph speed the the driver side tank was over flowing and dumping fuel out the cap. I know why this is happening kind of. My fuel system is rigged as follows. 2 12 gal tanks with -8 bungs welded at the rear bottom of the tanks. both fuel lines go from the rear of the tanks to a - 8 y block mounted above the hand hole cover above the pump in the rear of the boat. from there 1 -8 hose routes to the passenger side rear of engine block to a water fuel seperater then up the block half way to a airamotive fuel filter then to the airamotive fuel pump mounted on the hull directly behind the engine then up to the fuel rail on the tunnel ram. on the other side of the intake is the return where the regulater is mounted then to a -6 y block and 2 -6 hoses returning to each tank that was sopposed to return fuel evenly to both tanks. I think what is going on could be a few things one since the fuel pump is in fact closer to the passenger tank it may draw fuel easyier from that tank. I think my return set up is not working as planned sending fuel un evenly to the 2 tanks. I have no idea why. I want to know if it is possible to instead of running 2 return lines to each tank if it would work if i ran a y block right before the fuel pump returning the fuel from the fuel rail directly back to the fuel pump eliminating my fuel return issues. I'm worried this may cause a issue at low speeds or at idle because it will have more fuel returning than the engine will be using. besides a rise in fuel pressure what other things would i expect to happen? have any of you guys had this issue with efi, or even having issues with your fuel tanks not draining evenly. If any of you do have efi which I know is rare in a boat like these please let me know how you rigged your set up or any issues you had.

question # 2. Damm msd has to have a full 14 volts to run rite. Im having issues with this as well. I have 2 gold top duralast batteries on each side of the rear of the boat wired together with a perko switch there rigged to work as one but I can switch to run 1 to another if I want but cant because of my set up. there is too much wiring to run the boat on just one. I recently replaced with the motor a complete new wire harness from hardin marine. my question is. Is 1 altenater enough to power 2 good size batteries. I'm going to pull it off the boat and have it rebuilt to put out more power I hope this works. this efi set up draws a ton of power just the fuel pump alone will drain the batt fast if left on. do you guys have any issues with this sort of thing what is your adivice. I going for my second tryal next weekend I was hoping some of you experts can steer me in a time saving direction.

                                                           Thank You for you help and bare with my spelling
                                                                       Jimmy..
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ROMPERSTOMPER

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Re: Tech Questions for efi and fuel system issues
« Reply #1 on: February 04, 2010, 03:28:47 PM »
 Heres a few pics
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Luckie Stiff

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Re: Tech Questions for efi and fuel system issues
« Reply #2 on: February 04, 2010, 03:43:14 PM »
The fuel issue sounds like typical jet boat fuel shit. Make sure your hoses from your tanks are the EXACT same length from between the Y and the tanks. Otherwise it will always pull from the closest tank first. As to why the one tank is filling from the other? I couldn't tell you. Someone else will have to pipe up for the MSD issues.
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ROMPERSTOMPER

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Re: Tech Questions for efi and fuel system issues
« Reply #3 on: February 04, 2010, 03:49:00 PM »
thank you. I know that the main fuel lines from the tanks are the same length. the return lines may be a few inches difference. Got lazy towards the end of making all those damm an lines. Didnt think a few inches would make a big diff on the return.
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ROMPERSTOMPER

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Re: Tech Questions for efi and fuel system issues
« Reply #4 on: February 04, 2010, 04:01:28 PM »
bigger pictures
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Stevecat

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Re: Tech Questions for efi and fuel system issues
« Reply #5 on: February 04, 2010, 05:18:29 PM »
Also consider that the vent lines and/or the filler necks/caps on each tank may be flowing air differently, making one have more backpressure than the other.

Maybe you can think of a way to run it with the filler caps cracked open for awhile and see if anything changes.

You could maybe rig up a temp surge container of some sort. First try it on the return line so you can test out whether it is the return leg of your loop or the supply leg. If you put a temp surge container (something to let the return gas fill into and then gravity lines out of it back to the side tanks) and the problem goes away you know it's with the return sections.
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pw_Tony

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Re: Tech Questions for efi and fuel system issues
« Reply #6 on: February 04, 2010, 05:26:23 PM »
Could you just run one fuel bypass with a selector switch into which tank it goes into?

And what did you use to tune the fuel map at the dyno, your personal lab top?
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ROMPERSTOMPER

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Re: Tech Questions for efi and fuel system issues
« Reply #7 on: February 04, 2010, 06:30:23 PM »
Used a close friend of mine's lap top. of course his lap top crashed after I lost the tune so kissed it good bye. If i told you guys the bad luck I've had with this project and everything I've done twice or three times it would probably crash this site before you could read it. That's what type of luck I have with this boat. Now I'm using my brothers lap top and yes were saving each tune onto a flash drive to prevent that costly and time consuming error again. learn the hard way you learn more but it really sucks! :banghead:
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challenger

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Re: Tech Questions for efi and fuel system issues
« Reply #8 on: February 04, 2010, 06:50:47 PM »
Used a close friend of mine's lap top. of course his lap top crashed after I lost the tune so kissed it good bye. If i told you guys the bad luck I've had with this project and everything I've done twice or three times it would probably crash this site before you could read it. That's what type of luck I have with this boat. Now I'm using my brothers lap top and yes were saving each tune onto a flash drive to prevent that costly and time consuming error again. learn the hard way you learn more but it really sucks! :banghead:
whats up bro when are you going out for testing i will meet you out there
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Nordie

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Re: Tech Questions for efi and fuel system issues
« Reply #9 on: February 04, 2010, 07:02:06 PM »
i have always wondered if there was a way to run a hose to each tank and wonder if it would balance them out!
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TJS Nordic

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Re: Tech Questions for efi and fuel system issues
« Reply #10 on: February 05, 2010, 05:31:47 AM »
ROMP:
  I posted on this site how to modify my tanks for large pickups and in my 8-71 EFI build up I showed the cross-over balance hose. I will try and find the links later. Here is what I did.

I put large pickups (-12AN bungs with huge tubes on top of the tanks) in both tanks but only use ONE to feed the Aeromotive pump. I return to only ONE tank (-6AN) from the regulator. However, I have a balance cross over hose linking the 2 tanks together at the bottom of each tank. This makes the whole system act as one tank. I have never had a problem. I have even ran them down to ¼ of a tank and it was good. I now only fill up one tank at the gas pump and the balance hose (-12AN) takes care of filling both tanks evenly. Also I posted here where I made separate vents for the tanks because I do not trust the vented caps either. I think I have had these tanks out 4 times to weld/modify  them. Welding on these tanks is a little scary. Proper prep and procedure are a must.

T.J.

TJS Nordic

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Re: Tech Questions for efi and fuel system issues
« Reply #11 on: February 05, 2010, 06:26:22 AM »
I just went back and re-read your post regarding your wire harness and charging system. I am using one battery and do not have an issue. I built my wire harness for the regular boat stuff and my EFI harness is from Accel. I also wish I built my EFI wire harness from scratch cause I had to modify that as well for a cleaner fit. I am running a ONE wire alternator I think I got at Summit. I think it is a 65AMP alternator. Knock on wood it is working good. You are running your big MSD wires directly from the battery correct. Are you having issues with the MSD, if so what is happening.

Also getting back to your fuel system. You will have issues returning fuel back right before the pump. For one the fuel might be warm, which may cause issues with the Aeromotive pump. Return type EFI systems utilize the rest of the fuel in the tank to “cool” the fuel that is returned to it. As for your current return system now does not work as you already experienced, even though you tried making the return lines the same length does not matter. The only was is a balance cross over or a dual selector valve like the Ford trucks run, but those are going to take some nifty wiring and will not accept AN fittings. Also you would have to get a feed selector valve that is elect. Actuated which is not cheap. So when you switch to the left tank you also want to return to the left tank and vice versa. Sorry to say but your tanks gotta come out and be modified. Man I wish I lived out West. This is cake to modify that tanks for a cross-over balance hose.

Luckie Stiff

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Re: Tech Questions for efi and fuel system issues
« Reply #12 on: February 05, 2010, 08:28:20 AM »
Man I wish I lived out West.

You ain't the only one! You could really make a lot of people's lives easier if you were out here. You ever think of doing an e-commerce type shop?
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Sanger Pete

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Re: Tech Questions for efi and fuel system issues
« Reply #13 on: February 05, 2010, 09:29:42 AM »
Could you just run one fuel bypass with a selector switch into which tank it goes into?

This is what we did. I would have liked to get one of those $600+ electric selector valves with both fuel feed and return, but ended up with two identical manual valves--one for the feed lines and one for the return. That way I just switched both at the same time to draw from and to return to the same tank. Never had a problem.
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farmergord

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Re: Tech Questions for efi and fuel system issues
« Reply #14 on: February 05, 2010, 10:05:42 AM »
« Last Edit: February 05, 2010, 10:21:10 AM by farmergord »
  • Boat #1: 1976 Pioneer 19foot
  • Boat #2: 2020 Kingfisher 2025
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ROMPERSTOMPER

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Re: Tech Questions for efi and fuel system issues
« Reply #15 on: February 05, 2010, 10:46:36 AM »
TJS thank you for your post.           I knew you would have some good advice. I knew I should have done that.
 Question. If I run a big hose from one tank to the other do I really need a selector switch. Wont gravity even out the 2 tanks?. Man I don't really have room in my boat to do that As you know space is tight and my feed lines currently are 2 -8 bungs welded at the back bottom of the tanks where the balancing hose would go. I just had them tanks out to weld and polish, it is a huge pain in the ass to remove em  :banghead:   ugg it makes perfect sense though because that's the only thing I havnt done twice. TJS my efi is a fast xfi came with a harness  I as well had to modify i'm RUNNING A FAST DUEL SINC DISTRIBUTOR, msd 7 al box and hvac 7al coil. Ive gone over the wiring about 2 dozen times and have it wired very well. My efi is set to be full sequincel sp. Is yours?


I think my problem may lie in the alternater. I'm going to run a volt meeter on it this weekend. Its the only part I havent replaced in the motor swap. I was woundering if I have it rebuilt to 120 amp if it will be enough to keep both batteries charged at 14.5. It is a marine 1 wire alt. What happend was at the lake When I ran out of fuel on one side of the tank and the boat shut down that's the first thing I checked but I checked the wrong tank so ran the batt down tryin to start it. When I gassed up, the boat fired rite up but ran like shit on the low end poping didnt want to idle less responsive typical msd with low voltage.

TJS
How have you been tunning your efi ?
What impeller are you running?
How much hp ? Questimate
Are you running full sequencial or batch fire ?
What's your water temp at while running? Mine was very low like 120 150 the water was freezin tho.
What distributor are you running?
How fast is she running at what boost?
I love you boat! It's bad ass and reminds me of mine the way we rigged out boats. Believe me or not I got a ton of ideas from this forum and they have helped in a huge way. I Am greatfull for your and everyones help thank you.
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TJS Nordic

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Re: Tech Questions for efi and fuel system issues
« Reply #16 on: February 05, 2010, 12:17:56 PM »
You do not need any sort of selector valve if you are running a balance hose set up. Yes gravity will even out the 2 tanks making them act as one. That is the main reason why I did this. Plus it makes filling the boat up easy cause only filler has to be filled.

Sequential (easier to tune and idle vs batch)  MSD 7AL with the wiz bang MSD coil.A MSD Pro-billet Dist. that is modified for a cam-sync signal. I am swapping pulleys (going 10% over) and dyno tuning it in about a month or so. I know a good EFI tuner that is well known everywhere.
 
I have not dyno’ed it yet so last season I ran conservative. 6psi boost and AA stainless impeller. Don’t really know that top speed because I can’t see shit. My eyes water too much and afraid to stay in it, got to get better goggles, and yes I have a kill to and wear my safety vest. All I know I sawed off 2 bigger cube blower boats (Daytona and a Sleek) out of the hole and they never caught me. One was a real shit talker to his buddies too and I sawed him off in front of a sand bar where his buddies were watching.

TJS Nordic

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Re: Tech Questions for efi and fuel system issues
« Reply #17 on: February 05, 2010, 12:19:45 PM »
You ain't the only one! You could really make a lot of people's lives easier if you were out here. You ever think of doing an e-commerce type shop?

Yup I have done a lot of stuff though the mail for Mustang guys.
T.J.

ROMPERSTOMPER

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Re: Tech Questions for efi and fuel system issues
« Reply #18 on: February 05, 2010, 12:59:14 PM »
Nice love to hear you smoke on some shit talkers. I was going to run a pro billet but the fast duel sync just had came out so I went with it. I'm running a bronze a-b and it seems like its not enough. I don't have my top end tuned completely but it feels like it will easily rev to 8000 rpms. that's with out the 300 shot of nitrous. I may have to get a bigger impeller. I wounder how our boats would do in a race TJS. My first dyno tune put out 1020 hp at around 6700 on nitrous and 110 vp. about 750 hp without. I don't think it was that great of a tune tho. My brother is really good with tunning efi by expierance and trial and error. he's done electromotive hall-tec and now fast. he's gonna run excel on his 69 camaro 383 so he will soon be familiar with excel. I love and hate efi because there is so much you can adjust to really dial your motor in but it takes time to see what you motor likes, there all different.
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TJS Nordic

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IRRebel

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Re: Tech Questions for efi and fuel system issues
« Reply #21 on: February 05, 2010, 10:31:05 PM »
i have always wondered if there was a way to run a hose to each tank and wonder if it would balance them out!
The only was is a balance cross over or a dual selector valve like the Ford trucks run, but those are going to take some nifty wiring and will not accept AN fittings.

I'm glad for those answers. Gonna be a similar problem on my MFI deal, and I was kinda figuring on the same issues. There is NO WAY, to my mind, you are ever going to get both tanks to seal identically and flow evenly. A cross over line between them seems the least costly way to address this.

But would it not be beneficial to have a crossover line from the bottom, rear of the tanks (I'm assuming saddle tanks) as well as one from the top front? Just thinking out loud here. (A lot of hose, but eliminates a $600 switch that will still cause, in my lil brain, issues restarting when one tank runs out and you switch over, same as the Ford trucks have when it happens).

I think Nordie has some experience with this same phenomenon as well, on his carb'd deal at the AVI.

Ray

TJS, I'm with Skip, you NEED to move out here somewheres. Between Nick and you, we'd all have the sweetest sleds on the planet!
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Sanger Pete

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Re: Tech Questions for efi and fuel system issues
« Reply #22 on: February 06, 2010, 01:45:47 AM »
I would think that in order for gravity to balance the tanks, the cross over hose would have to connect at the bottom of the tanks. Although I like the idea of filling both tanks from one side, wouldn't that create a safety problem--filling the bilge with fuel (emptying both tanks) if there was a break in the line? I thought that is the reason that newer tanks feed from the top. I could see some safety inspection and/or insurance issues with this setup.

We also found that the aeromotive high pressure fuel pump we used was much better at pushing than it was at sucking. Had to blow into the fills to help prime the pump a couple of times.
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honda1

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Re: Tech Questions for efi and fuel system issues
« Reply #23 on: February 06, 2010, 06:14:41 AM »
I would think that in order for gravity to balance the tanks, the cross over hose would have to connect at the bottom of the tanks. Although I like the idea of filling both tanks from one side, wouldn't that create a safety problem--filling the bilge with fuel (emptying both tanks) if there was a break in the line? I thought that is the reason that newer tanks feed from the top. I could see some safety inspection and/or insurance issues with this setup.

We also found that the aeromotive high pressure fuel pump we used was much better at pushing than it was at sucking. Had to blow into the fills to help prime the pump a couple of times.
  HAHA Rays good at that  ;D got ya back bud just funnin lol
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Nordie

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Re: Tech Questions for efi and fuel system issues
« Reply #24 on: February 06, 2010, 08:35:43 AM »
I think Nordie has some experience with this same phenomenon as well, on his carb'd deal at the AVI.

Ray

TJS, I'm with Skip, you NEED to move out here somewheres.<~~Agreed

Ray this is true i know my tanks have some very serious issues that need to be addressed....my port tank leaks from the sending unit when tank is full....my starbord tank leaks from the fill hose that goes to the tank, and also has a pin hole somewhere in the bottom...tanks are coming out this weekend when the weather lets up, and i need to find a welder....it is true that the tanks definately vent differently...my port tank loses 2-3psi on the fuel pressure guage vs the starbord tank....my plan is to have the tanks rewelded and a new sending unit that will work with the guage, and new hoses and fuel fills...it will be inexpensive vs a human life, and save me some gas
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