Regina 740 dies on right turns Topic is solved

[jpgurley]

Thanks to RickHaleParker for the suggestion of raising the side of the car.

I put ramps at both right wheels to simulate the making a right turn and the fuel pressure went to zero within a few seconds. I have pulled the pump assembly and there is still about 2" of fuel in the plastic "well" where the pump sits, but it is definitely not pumping any fuel.

It would seem like the fuel would be deeper on the driver's side of the tank with the right side lifted, but that's what I have. I checked to see if the baffle, or well, was loose and or could move but that's a negative,

I feel like I am looking right at the problem but not seeing it.
Any suggestions would be appreciated.
Jon

[RickHaleParker]

I put ramps at both right wheels to simulate the making a right turn and the fuel pressure went to zero within a few seconds.

Have you figured out what the fuel balancing system is?

Need to confirm by testing if the pump is not picking up fuel, being blocked/lost between the fuel pump and fuel rail or the pump(s) is being turned off. That should narrow the source of the problem.

1989 schematic shows two fuel pumps. One in the tank the second next to the fuel filter ... under rear seat? The in tank pump ground is in the boot.

BlackBart might be on to it. Two different Combined tank units ( Sender, Fuel pump and frame ) for the 740. One for the 60 liter (15.8 US gallon ) tanks used with ridge axles and one for the 80 liter ( 21 US gallon ) tanks use with multi-link suspension. Make sure you got the right one. A PO may of installed the wrong one. Measure the depth of the tank where the fuel pump is and compare it with the depth of the combined tank unit.

[RickHaleParker]

Don't quote me on this but I think the 60 liter tank is aluminum and the 80 liter tank is plastic.
Your rear suspension type should tell you which one you have.

1982 - 1990 Combined Tank Unit are different still. Need to make sure it not one of them.

1991 - 1992 740 60 liter Combined Tank Unit.


1991 - 1992 740 80 liter Combined Tank Unit.

[jpgurley]

You guys are being very helpful.

A couple of things:

The pump is still running but not producing pressure. Not even at the output from the tank.

The Regina cars only have the one pump. Under the car is just the filter that's the same as a Bosch filter.

The voltage at the pump is 11.3 though the battery is over 12. But I still hear the pump running. I don't think that's enough voltage drop to keep the pump from producing pressure though. Didn't check voltage before I tilted the car.

The car is solid axle and plastic tank. The original pump assembly was the factory unit with undercoating indicating that it had never been disturbed.

I am fairly certain that the unit is somehow sucking air and I will do some more measuring on depth.

I'm considering trying to find a used plastic tank but not sure that's going to change anything.

Thanks for all your research guys.
Jon

[jpgurley]

Mystery solved!
It was water in the fuel tank!
The air bubbles that I was seeing on the clear return line was the water "boiling" with the gas as it came down the fuel rail.
There was enough gas to overcome the issue until the tank got low and the water sloshed to the pickup sock.
Also the time it failed (or created a skip) at highway speed with 3/4 tank it was a very hot day so I think the invading water was quicker to boil.
When I drove the right wheels up on the ramps the car died in less than a minute as the fuel pressure dropped to zero. In a way it was like a vapor lock on a 40+PSI fuel line.

So my theory is that several things were happening:
A full tank ran cooler and didn't bring water to a boil,
A 1/4 tank ran hotter
A right hand turn caused the water to become more concentrated in the pick-up "well" of the tank and immediately killed the engine.
Also it was worse when it was 90+F outside.

I have been trying to figure this out since November.
Perhaps being on serious pain relievers after a quadruple bypass surgery when I first got this car is the reason I didn't get all the old fuel/water out of the tank.
That's my excuse and I am going to stick with it.
Thanks again guys.

Tomorrow I fill 'er up with fresh gas a little alcohol (Would vodka work?) and take it for a drive.
Grateful in Carolina.
Jon

[RickHaleParker]

Mystery solved!
It was water in the fuel tank!

Condensation from sitting all them years. This year I had to drain the tank and the bowl on my power washer for the same reason. Keep that in mind the next time your lawn mower will not start up after being stored for the winter.

US Vodka .... that stuff is 50% water ( 100 poof ( 50 % ) is the legal max ) .

Isopropyl alcohol binds with water and lets it burn.
Ethanol does the same thing but not good for storage because it separates over time. Just fill it up with a Ethanol blend and drive it.

[jpgurley]

Great advice on the Isopropyl alcohol.
I found some 91% in the medicine cabinet and poured in a quart.
I had not thought about the ethanol in gas.
I thought about using some E85 but can't find any through gas buddy in the area.
Guess some more alcohol would be my best bet to clean out any more moisture.
It amazes me how well this old brick has been running with that much water in the tank.
I'll bet a P2 car would be throwing CEL's like crazy!
Thanks again.
Jon

[lummert]

Glad you weren't able to locate any E85 in your area. Your car most likely isn't set up for E85.

[RickHaleParker]

I thought about using some E85 but can't find any through gas buddy in the area.

E85 is too much alcohol ( 83 -85 % ). It can damage the engine. Just run a Ethanol blend like E10 - E20 for a couple of tanks.