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-   -   1999 Supercharged 454 problems (https://www.offshoreonly.com/forums/general-q/185287-1999-supercharged-454-problems.html)

lilwigs 04-29-2008 08:57 AM

Thanks kennyo! You are correct about me being in over my head. My problem is I'm in Nebraska and can not find a shop willing or able to workon my setup. They did find two fouled plugs and replace the impeller, but that was all the marine store could do for me.
I hear the general concensus and think taking it off is the way to go. Thanks for all of your help and wish me luck...giving it another month, then there may be one heck of a steal on a 99 Chappy on ebay for the right person.
Thanks all!

Big Cliff 04-29-2008 09:12 AM


Originally Posted by lilwigs (Post 2541741)
Thanks kennyo! You are correct about me being in over my head. My problem is I'm in Nebraska and can not find a shop willing or able to workon my setup. They did find two fouled plugs and replace the impeller, but that was all the marine store could do for me.
I hear the general concensus and think taking it off is the way to go. Thanks for all of your help and wish me luck...giving it another month, then there may be one heck of a steal on a 99 Chappy on ebay for the right person.
Thanks all!


Don't give up, but DO NOT run the boat hard untill its figured out.

If the fuel pressure is jumping around that is a main problem. Make sure your fuel pressure regulator is good. Make sure your fuel pump is good. Make sure your filter is clean.

Are you running this boat on 93 pump gas? I'm sure it needs it.

Get in there and get your hands dirty.

RunninHotRacing163.1 04-29-2008 09:28 AM

[QUOTE=lilwigs;2541741] My problem is I'm in Nebraska and can not find a shop willing or able to workon my setup. giving it another month, then there may be one heck of a steal on a 99 Chappy on ebay for the right person.

Wigs before you put it on ebay let us know if your gonna move on to another boat and we'll come get it :cool-smiley-011::D good luck

1BIGJIM 04-29-2008 11:48 AM

[QUOTE=RunninHotRacing158;2541786]

Originally Posted by lilwigs (Post 2541741)
My problem is I'm in Nebraska and can not find a shop willing or able to workon my setup.

Where are you at in Nebraska?

lilwigs 04-29-2008 02:35 PM

I'm running 91 octane pump fuel. I'm located in Lincoln, NE unfortunately. I pick it up from the shop today and afraid it'll be another few weeks till I can get this in someplace else but not sure where. I'm pretty mechanical, but never really had to troubleshoot this type of deal. When the fuel pressure guage jumps I'm not sure if it's the "cause" or effect of it missing at those rpms. I did find out the impeller did need replacing and they removed a piece of plastic that was blocking my upflow of water. It was still pumping though? I did have them replace the old fouled plugs with the NGK 5 or 6. Is advancing the timing something anyone has done with the computer. I was under the assumption the taking the tstat out was to trick the motor into dumping more gas and the charger wouldn't need any additional setting changed on the motor.

lilwigs 04-30-2008 02:35 PM

For anyone not tired of my questions I think I have my problem narrowed down, but could use some final advise. With new plugs and impeller replaced it is running better. This was not my issue, but in running it for an hour last night I did notice my fuel pressure when I turned on the key was right at 40, then under normal running it would run 30-35. Under full boost at around 4000 rpm I can see the pressure fall to 20-25 and then it starts to cutout and surge as the pressure goes from 20 - 40. Just out of curiosity, I put a kink in the vaccum line to the regulator and to my surprise no performance difference. So that said I'm almost positive its in the fuel supply somewhere. Unfortunately I know nothing on this topic. I'm assuming the pump is fine since it hits 40 on turn key, but somewhere in the process I am unable to keep pressure. Looking at changing the seperator and fuel filter, but is my next step a new regulator? How can I test without just changing piece by piece? Thanks in advance to anyone who can help!!

DMOORE 04-30-2008 03:21 PM


Originally Posted by lilwigs (Post 2543588)
For anyone not tired of my questions I think I have my problem narrowed down, but could use some final advise. With new plugs and impeller replaced it is running better. This was not my issue, but in running it for an hour last night I did notice my fuel pressure when I turned on the key was right at 40, then under normal running it would run 30-35. Under full boost at around 4000 rpm I can see the pressure fall to 20-25 and then it starts to cutout and surge as the pressure goes from 20 - 40. Just out of curiosity, I put a kink in the vaccum line to the regulator and to my surprise no performance difference. So that said I'm almost positive its in the fuel supply somewhere. Unfortunately I know nothing on this topic. I'm assuming the pump is fine since it hits 40 on turn key, but somewhere in the process I am unable to keep pressure. Looking at changing the seperator and fuel filter, but is my next step a new regulator? How can I test without just changing piece by piece? Thanks in advance to anyone who can help!!




Just a couple things. First NGK 5/6's are HOT plugs. Be sure this is what you should be running. Call procharger and ask. Second, the fuel pressure should not be falling off. I believe this is where your problem lies. I personally wouldn't run the boat with it doing that.
That is the PERFECT way to damage a piston. You are on the right track, change out all of the fuel filters, and water seperators. And, be sure there are no blockages in the lines. After this is done, then, start to look at the regulator and pump.


Darrell.

Fountain38SC 04-30-2008 03:53 PM

Just my. 02. You have a fuel problem no doubt about it. There is a difference between a fuel pump and/or system making pressure at idle and it not being able to keep up with demand at higher rpms. My guess is the entire fuel system is inadequate or improper and that the prior owner couldn't make it work.

I will second all of those that have said that you are going to hurt the motor running it that way. I learned the hard way years ago. I would never again guess at the problem. You really need to get someone who knows what they are doing or forget the procharger. I hope you don't learn an expensive lesson.

blue thunder 04-30-2008 04:40 PM

Make sure your fuel tank vent is not plugged of restricted. When you fill will fuel can you do it on full flow without the gas station pump nozzle clicking off?

RBeyer 04-30-2008 05:45 PM


Originally Posted by DMOORE (Post 2543644)
Just a couple things. First NGK 5/6's are HOT plugs. Be sure this is what you should be running. Call procharger and ask. Second, the fuel pressure should not be falling off. I believe this is where your problem lies. I personally wouldn't run the boat with it doing that.
That is the PERFECT way to damage a piston. You are on the right track, change out all of the fuel filters, and water seperators. And, be sure there are no blockages in the lines. After this is done, then, start to look at the regulator and pump.


Darrell.

I agree with the fuel regulator on an aeromotive fuel system. The vacuum regulated fuel regulator is to increase pressure with boost. I think you have a bad diaghram in the regulator. It is kind of common.
Bob


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