fuel pump how hot is to hot 76-79 fuel injection

[vw76westy]

76 bus with original fuel injection





my bus has been randommly bucking kicking and dieing on me
for awhile now

but problem gos away when im trying to find the failing part

one day i noticed the fuel pump was really hot

so i replaced it with a spare i had and thought i found problem

spare also ran hot

so i went and bought a brand new pump

that also got hot ???


at this point i could only assume there is junk in the gas tank
and the pump is starving for fuel to keep cool

cause its a NEW pump


but before diving into removing gas tank for cleaning

i wanted to make sure the new fuel pump is good

so i removed pump from bus
ran fuel line from a gas can to fuel pump and powered it for an hour or so

the pump temp was in the 100degree neighborhood (very warm but not hot)
with gas free flowing , no resistance from a pressure regulator
or heat from a running vw


as far as i can remember the fuel pump should run cool
and for no reason get warm or hot.....


so .... is the new fuel pump defective
or is a warm fuel pump ok
and i need to check gas tank
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quote from bay window bus buyers guide........
The Type 4 engine is considered by many to be VW's finest air-cooled motor,

[Cap10323]

Yeah, the fuel pump should be cool, as I believe it is cooled by the fuel flowing through it.

IIRC the fuel pump on my Bus is cool to the touch while running.

I would try a new fuel pump.
_________________
-Ian

'77 Westfalia - 2.0 F.I

[vw76westy]

thanks for confirming

its what i thought

it just hard to believe that i handled so many bad fuel pumps in a row....
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quote from bay window bus buyers guide........
The Type 4 engine is considered by many to be VW's finest air-cooled motor,

[Mile High Puma]

I would look for a restriction in the fuel system, IIRC there should be flow from the pump back to the tank continuously when running.
_________________
1965 Velvet Green DC

[ivwshane]

You say you got a new pump but my research came back with not all fuel pumps being the same and some are garbage. So where did you get your new pump from and what brand/manufacture origin is it?
_________________
77 westy 2.0 FI
69 ghia coup 1600dp
70 single cab

[telford dorr]

Do a bench test:

- remove the fuel pump, filter, and pressure regulator from the bus.

- connect all together with some appropriate hose. Only the hose from the pump to the regulator needs to be high pressure hose.

- stick a hose from the filter into a gallon gas can, 1/4 full of gas.

- stick a hose from the pressure regulator into the same gas can.

- connect 12 volts (remotely!) to the pump.

- the pump should briskly pump gas from the can through the pressure regulator and back into the can. If it does so, run it for a while and see if it gets hot. If not, suspect the tank - see if fuel flows freely from it (try to avoid gas in the armpit...)

- if the pump flow is low, try it without the pressure regulator. If the flow is good, check the pressure regulator.

Note: if possible, do this outside so as to minimize flame damage, should anything go wrong. Have a fire extinguisher handy, and an escape plan...
_________________
'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)

[Wildthings]

What is your ambient and how long have you been running the engine. While the fuel does cool the pump, the only thing cooling the fuel is air flow around the tank, so the fuel in the tank will be higher than ambient at best and if you are idling your engine for a long period of time so there is little or not air flow over the tank then the fuel can get very hot. When I have used my Toyota truck as a tractor pulling a drag during the heat of summer, before I learned better I once let the fuel got so hot it was boiling in the pressurized fuel tank. Lucky I didn't create an explosion and inferno.

[aeromech]

First we have Steve Kent return and is this Raul? Is this the guy I tried to help once broken down in San Diego?
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
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Boeing 727,737-200-300-400,757,767
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Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[danfromsyr]

check and clean the ground wire for the fuel pump
if the ground wire has too much resistance it'll cause the pump to run hot.

might need to change it for a new (larger) one with fresh copper.
_________________

[Wildthings]

[raygreenwood]

All of this is correct.

To add to this....as danfromsyr noted.....that high ground wire resistance can start at the pump ground wire female connector.

And in the same vein.....if you have low voltage to the pump, either from poor internal and external connections in the relay or in the power feed due to cordoded connections or bad wires anywhere in the loop or evrn a nad regulator.....you csn have a hot runnimg pump.

The first easy diagnosis stop is to check fuel system pressure and volume. And of the possible issues being suggested so far in this thread.....can and will cause low or variable pressure.

Ray

[ImAddicted]

When you check the tank, don’t forget to check the hard line that runs parallel to the tank over to the filter. My tank had good flow, that metal line was clogged to hell (among other issues in fuel delivery).
_________________
1979 Transporter (sold)
KC1MUR

[vw76westy]

Mile High Puma
before putting a whole lot of time into fuel tank

i need to be 100% that fuel pump is not the problem

aeromech
yes this is raul
funny my bus hasn't been this big a headache since that time in
san diego



Wildthings

great point about ambient temp


to get real detailed on how i bench tested.......

the pump was placed on the ground in a shaded area outside the bus
sm battery fan a few feet away just to help dissipate fumes
ambient temp was around 90
about 3ft of fuel line in and out
with fuel filter, without pressure reg
going into a very clean plastic gas can with 2 gal of gas in it

ran pump for an hour or so

consistant temp of 99 degree was measured using a temp gun


no heat coming from direct sunlight or from a hot motor
no resistance from a pressure reg


the pump is in best possible case scenario to run cool
with no possible variables for it to run hot


i think under these circumstances
the pump ran unacceptably hot

but because its a new pump

and mentally i want the problem to be pump and not something in tank
i kind feel the need to question my own opinion

and get a unbiased opinion on

"how hot is to hot"
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quote from bay window bus buyers guide........
The Type 4 engine is considered by many to be VW's finest air-cooled motor,

[ImAddicted]

If it helps any, I just came back from an hour drive with my ‘79. Ambient temp: 91F. Speeds: 35-55 rural driving. Fuel pump location: stock, near exchangers. Thinking of you, when I returned, I placed my had on the pump (still running) immediately after getting out. I don’t have a cool thermometer, but the pump body was noticeable cooler than body temp, so no where near 99F.
_________________
1979 Transporter (sold)
KC1MUR

[Wildthings]

[Jetfxr69]

You swapped out an old pump for another used pump ( of unknown condition?). And when that didnt help you put in a new pump. So two old and now one new, correct? And as IVW asked, “ what kind or what quality new pump?”

Theres alot of shit on the market. Ive got a box full of pumps and have swapped in older noisier pumps for new pumps just because they work better albeit noisier.

If youve gone through three pumps, and they all exhibit the the same perceived high temperature, then that tells me that the pump is probably not the problem. I think your avoiding the real issue that would cause three different pumps to do exactly the same thing.

Definition of insanity is doing the same thing over and over and expecting a different result.

Start looking at other causes of why the pump would run hot as all these guys keep saying.

Clean or replace all electrical connections including grounds. Pull fuel line off from both side of the tank and either confirm no blockage or debris or just replace with new. If you have the steel feed line like Addicted said, snake it with a pipe brush and make sure its not restricted from internal rust. Run some small pipe cleaners up the tank nipples. Spend $50 and put a fuel pressure gauge on it at the test port between 3 & 4. Do the Bentely FP test as outlined in the book.

Process of elimination will find you a fix. The things above would take an hour to do. When youve done all those things, and then report back that your pump is still running hot, THEN, you buy another pump. And this is assuming that youve isolated that fuel delivery is actually the culprit of your bucking and dying that you first mentioned.

You might be spinning your wheels (or not), chasing this pump issue, and thats not even the cause of your engine troubles.

My opinion, away from the pump, is that your TSII or double relay is acting up. FI busses are very finicky due to tiny electrical issues. A momentary lose of ground to the DR will cause all kinds of havoc. Dirty or corroded connection where the TSII touches the head will cause problems. Dirty or corroded ground straps, the same.

Its not rocket science. It may have been back in the seventies, but not today.
_________________
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‘77 westy Seamus
‘76 tintop Crusher
‘77 westy The Judge
‘72 tintop bastard westy Hudson

[vw76westy]

ImAddicted

thats exactly the kind of info im looking for
right now...


Jetfxr69

because i agree with this statment

[vw76westy]

in a separate note

but still on subject of fuel pumps


i had 5 fuel pumps in my spare parts

all were pumps that i ran in my bus for at least 1000 miles before confirming
that it was good and reliable spare before
swaping to another pump

i haven't been selling parts for about 3 yrs now
that said
these pumps all sat on a shelve for at least that amount of time

4- of the 5 pumps sprung leaks

i mention this because i want to remind people that

the seals inside a fuel pump will dry rot if not kept wet with fuel

this is not a part you want to keep in a spare parts box
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quote from bay window bus buyers guide........
The Type 4 engine is considered by many to be VW's finest air-cooled motor,

[60vwnewengland]

Did you check the fuel pressure? Should be about 26-28psi at idle. Rev the engine and watch the fuel pressure gauge, it should stay around 26psi or may dip to 24-22psi. Anything below 20psi and your bus will run like poop. It’ll idle, but not allow you to accelerate. Here’s a video of how my bus was acting with clogged fuel line that was full of rust.

Link


If your gas tank is rusty, the chunky bits could be blocking the line and fuel filter.

If you can check fuel pressure, if it’s low (like 5-10psi) then you can guess the gas line/filter or tank is blocked.
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77 Westy - Cape Cod Sage
LLAP

[cmonSTART]