• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

240 Befuddled . . . .

TestPoint

Active member
Joined
Jul 15, 2009
Location
Ellijay
I am tired of thinking about this car. ('81 Bertone) See link below for 5 years of discussions on all the problems.

I drove it to the paint shop and back about 3+ years ago then put it on HF jacks stands to age . . . and finish off all the cosmetic work. Heart valve replacement and a torn rotator cuff later it is time to get it off the jack stands.

Starts on starter fluid.

Hooked up the TurboBricks brand fuel pressure test equipment and only get 20 psi at the Control Pressure Regulator with the valve open and that is close . . . but . . . with the valve closed I get the same reading. Should be 70 psi. Both pumps are running in 'start' and jumpered at the fuel pressure relay.

Both lift and pressure pump have been replaced since I tried to pump 20 years of gas tank rust through them some years ago. Remember, it ran 40 miles to/from the paint shop since anything was done to affect the fuel system.

Other than spraying gas everywhere the fuel distributor to CPR connection is the only place I know to open the system to test pressure. A hose blew off the V8 conversion project at 90 psi and dumped a gallon of gas in about 5 seconds so I am aware of what that much pressure will do. I ran.

Since I replaced the original completely failed pressure pump with a cheap universal pump that probably cost $20 on ebay that didn't even physically fit I upgraded to a $30 pump that did fit the mounting hardware. Bench tested it before installation. It is marked + and - so got that correct and it is pumping some gas.

CPR reading with valve closed remains 20 psi. My logic process says that even if severely restricted the pressure should have gone up over a minute or two.

The only thing that I can think of that would maintain a steady inappropriate pressure is that the fuel distributor pressure regulator is stuck open to some extent and dumping all the pressure back into the tank.

Commiseration and thoughtful analytic comments appreciated.
 
Last edited:
OK if your gauge is accurate your kjet main system pressure is much too low. This could be due to the $30 pump being inadequate to flow and have the pressure for your kjet to work. System pressure should be at least somewhere around 65-75 psi if you close the valve. Open valve means control pressure in the line from the top of the fuel distributor to the CPR.

Personally, I would suspect the fuel pump before I would suspect an open pressure rgulator. But I do concur that it is a possible problem if the pump is good. But I'm following the clues and 20psi means your pump is not good enough.

BTW 20psi doesn't open the injectors. I think they usually open somewhere around 36psi.
 
Last edited:
I am tired of thinking about this car. ('81 Bertone) See link below for 5 years of discussions on all the problems.

I drove it to the paint shop and back about 3+ years ago then put it on HF jacks stands to age . . . and finish off all the cosmetic work. Heart valve replacement and a torn rotator cuff later it is time to get it off the jack stands.

Starts on starter fluid.

Hooked up the TurboBricks brand fuel pressure test equipment and only get 20 psi at the Control Pressure Regulator with the valve open and that is close . . . but . . . with the valve closed I get the same reading. Should be 90 psi. Both pumps are running in 'start' and jumpered at the fuel pressure relay.

Both lift and pressure pump have been replaced since I tried to pump 20 years of gas tank rust through them some years ago. Remember, it ran 40 miles to/from the paint shop since anything was done to affect the fuel system.

Other than spraying gas everywhere the fuel distributor to CPR connection is the only place I know to open the system to test pressure. A hose blew off the V8 conversion project at 90 psi and dumped a gallon of gas in about 5 seconds so I am aware of what that much pressure will do. I ran.

Since I replaced the original completely failed pressure pump with a cheap universal pump that probably cost $20 on ebay that didn't even physically fit I upgraded to a $30 pump that did fit the mounting hardware. Bench tested it before installation. It is marked + and - so got that correct and it is pumping some gas.

CPR reading with valve closed remains 20 psi. My logic process says that even if severely restricted the pressure should have gone up over a minute or two.

The only thing that I can think of that would maintain a steady inappropriate pressure is that the fuel distributor pressure regulator is stuck open to some extent and dumping all the pressure back into the tank.

Commiseration and thoughtful analytic comments appreciated.

Should be a good steady stream from pickup pump, it may be running backwards even though the terminals seem to be marked correctly.
 
Thanks for the thoughts.

New pump displays the same pressure the previous pump did. Car ran before and without changes to fuel system except that I put another 5 gallons of fresh gas in the tank.

Crimping the return line might provide a clue. Tomorrow.

I thoroughly understand the K-jet pressure regulation. It is just that there are limited ways to test the pressure.

I have had the fuel distributor off so many times I think it is only a 10 minute job now.
 
This is going to start a flame war however I have had repeated problems with modern gas turning to varnishy goo in a relatively short time in boats and small engines. Plugs up carbs and injectors. If that gas sat for a while in the tank, mayhaps you sucked up some goo?
 
Thanks for the thoughts.

New pump displays the same pressure the previous pump did. Car ran before and without changes to fuel system except that I put another 5 gallons of fresh gas in the tank.

Misery loves company.....

I know nothing about KJet fuel, but my Engineering brain needs exercise this morning.

1) Does the greenbook provide testing sequences for the fuel system on your 81?

2) Is the fuel system identical to the redblock KJet fuel systems?

3) From a pump design standpoint, it should be capable of a certain high pressure "deadheaded" without flow. Depending upon pump design this can cause current to spike..... and also might not if well designed. I doubt it can be found, but every pump has a pump curve, which shows flow rate vs. psi/kpa. Any chance you can find said curve for your OE KJet fuel pump?

4) Was your rust filled transport system from the tank to the CPR complete replaced? Are there any other pressure reducing devices designed into the system?

5) Can you still buy the OEM parts for your fuel system, instead of the TB cheap alternatives?
(When all else fails, return to Genuine GM Goodwrench parts........)

That's it..... I'll follow along, but don't have time to read the 5 trail of tears.

Good luck. When I get my Goldwing reassembled, I'll be up to see you.

EDIT - I also have been "too close to the problem" to see the root cause. What I tell my Maintenance Techs. is that 1) something you believe to be TRUE is FALSE...... and 2) most of the time it is behind you.
 
Holley efi that biatch, drive/enjoy it while you can and save the old parts. When your estate sells it -- "....all original fuel injection parts included...". That's the best I've got Tom.
 
Holley efi that biatch, drive/enjoy it while you can and save the old parts. When your estate sells it -- "....all original fuel injection parts included...". That's the best I've got Tom.

I've MegaSquirted my 70 Chevelle.... If I can do it, TOM can do it. :-P
 
1) Does the greenbook provide testing sequences for the fuel system on your 81?

Sorta, but it is basically testing the control pressure and fuel distributor pressure regulator with the setup I am using displaying incorrect pressure.

2) Is the fuel system identical to the redblock KJet fuel systems?

Yes, with a couple extra injectors.

3) From a pump design standpoint, it should be capable of a certain high pressure "deadheaded" without flow. Depending upon pump design this can cause current to spike..... and also might not if well designed. I doubt it can be found, but every pump has a pump curve, which shows flow rate vs. psi/kpa. Any chance you can find said curve for your OE KJet fuel pump?

The specs on 'deadheaded' is about 75psi at the point I am reading 20 psi. This and similar pumps are intended to be 90psi (6 bar) capable. Since I have two pumps with similar pressure readings for the moment I am going to look elsewhere for the problem.

4) Was your rust filled transport system from the tank to the CPR complete replaced? Are there any other pressure reducing devices designed into the system?

The fuel system was almost completely replaced. CPR rebuilt, fuel distributor rebuilt, new filter, new pumps, new tank and even a new gas cap. Hoses flushed out. The fuel pressure to the system is regulated by the internal regulator in the fuel distributor. That returns excess pressure to the tank.

5) Can you still buy the OEM parts for your fuel system, instead of the TB cheap alternatives?
(When all else fails, return to Genuine GM Goodwrench parts........)

Pretty much only the pumps. Bosch still available at $300 for pressure pump,
$100 for Delphi.


Today's plan is to drain most of the gas out of the tank using the lift pump then experimenting with lift pump only pressure at filter and fuel distributor. Problem is that there is limited connection capability anywhere other than the current test points.
Goldwing? I rode 4 Goldwings 100k miles over 25 years.
 
Last edited:
Hooked up the TurboBricks brand fuel pressure test equipment and only get 20 psi at the Control Pressure Regulator with the valve open and that is close . . . but . . . with the valve closed I get the same reading

Are you using a hardware store water pressure gauge? Those things are notorious for failing/sticking after sitting around for a couple years. Maybe your fuel pressure is OK but the gauge is bad?
 
The TB pressure gauge matches the compressor gauge and my HF lab quality vacuum/pressure gauge within 2-3 psi.

Disconnected and set up to drain the tank with the tank pump. Nothing comes out. I can hear the pump running but nary a drop of gas.

1. Pump wiring reversed but remember that this thing drove 40 miles three years ago.

2. Short hose between pickup and in-tank pump off or deteriorated. New pump, hose and filter 3 years ago.

3. Fuel filter sitting in goo. New tank, new gas 3 years ago.

Manana.
 
This is going to start a flame war however I have had repeated problems with modern gas turning to varnishy goo in a relatively short time in boats and small engines. Plugs up carbs and injectors. If that gas sat for a while in the tank, mayhaps you sucked up some goo?

The TB pressure gauge matches the compressor gauge and my HF lab quality vacuum/pressure gauge within 2-3 psi.

Disconnected and set up to drain the tank with the tank pump. Nothing comes out. I can hear the pump running but nary a drop of gas.

1. Pump wiring reversed but remember that this thing drove 40 miles three years ago.

2. Short hose between pickup and in-tank pump off or deteriorated. New pump, hose and filter 3 years ago.

3. Fuel filter sitting in goo. New tank, new gas 3 years ago.

Manana.

3 year old gas is old gas. Back in the day before ethanol, gas would last a lot longer in storage than it does today. I have had modern gas varnish up in a little over a year.

Also Never assume that the work you did in the past is still good and don't over think. Always go simple first, and work your way through a system. Starting at the intank, and making sure it is delivering good gas to the main pump should have been a starting point. Then make sure the fuel is coming out of the main pump at the correct pressure. If you find gummy goo in the tank, assume it is throughout the system. Not a bad idea to check the injectors as well, in case one got plugged with gummy goodness. If they are flowing enough to run the car, make sure you get some fuel system cleaner into the gas to hopefully breakdown and pass any gummy stuff in the lines. Change/clean the intank sock and replace the fuel filter.
 
Pulled the lift pump and found the hose between the pump and exit tube had dissolved. Yeah, it looked like a butyl hose expected to work submerged in gas. Even the rubber top cover of the pump was distorted.

Bertone%20lift%20pump.png


Hard to believe that anyone selling gasoline fuel pumps would do that. It was about the same difficulty cleaning up as if it had been butyl. I was able to disassemble without getting the black goo into the fuel level sender so it is reusable.

Guess I am off to the web parts store. Anyone got a specific recommendation?

DAMN PhotoBuckets. Now I have to figure out how to shrink the picture. Wish this forum would put internal storage back up and automatically size pictures. I know it is no big deal since the JaguarForum has been doing it for the past 10 years.

It didn't appear to have been able to pump much gas before completely failing and I can only hope that the fuel filter caught most of anything that moved.
 
Last edited:
Back
Top