Fuel pump

[silentdub]

I read on several posts how people keep their Petrol Fuel pump for one of two reasons.

1. The IDI pump is weak and needs a boost.

2. They put a switch in to make priming easy when they run out of fuel.


As some of you know from my other posts, I am dropping a 1.6 in to a 90 jetta. am I able to keep the fuel pump in place, or should I add a switch just to prime it?

I am not sure what the benefits are for adding one.

[bajacalal]

I've always wondered if you could use a stock VW carburated mechanical fuel pump as a supply pump for the diesel. The engine block even has a place where a fuel pump would bolt up. I forget if there is anything underneath it to actually drive the pump.

[Patrick]

I put a diesel in a '92 gas jetta at the end of march. eliminated the pump outside teh tank and hooked everything up. Car ran fine, but was running out of fuel with 3/8 of a tank left. Wired the pump in the tank to go live with the key, been fine ever since. Other option is to remove the pump in the tank. I just found the right wire on the back of the fuse panel (I believe it's red/yellow in the plug off the harness from the tank, but check A2 resource)  cut it off that plug, put a male spade on it, and plugged it in the front of the panel in a spot that went live with the key. Works like a charm. Might actually advance my timing a little, I'm not sure. Runs great, and easy to prime! Be careful, it WILL push major amounts of fuel out of the line under the hoof if it's not connected and the key is on. Return line has no problem handling excess fuel.

[J Z]

Maybe I just had bad luck with petrol pumps... 
I have tried using 2 different petrol intank pumps, but they have stopt working after a few weeks.
Now I use a diesel pump from BMW 525 and it works great.
Plugged red/yellow in with the taillights.

[JGWarner]

I am back on the fence about this with my TD Fox project. Should I bother trying to find a fuel pressure regulator for diesel? It seems like it would be simpler and easier and cheaper to just delete the in tank pump all together.

[silentdub]

I plan on having the pump rebuilt, so I may just keep factory fuel pump and wire it up on a switch, if it works without it, then great, otherwise I can kick it on.

I understand that the IDI pump on the MK1 is all you need unless the pump gets weak over time. Some people I heard add an electric pump when their IDI pump gets weak.

I guess I can try it either way and see the difference.

[keaton]

I've always wondered if you could use a stock VW carburated mechanical fuel pump as a supply pump for the diesel. The engine block even has a place where a fuel pump would bolt up. I forget if there is anything underneath it to actually drive the pump.

I have been thinking the same think. i was going to make a thread about it at one point but never did......
i don't see why it would not work... its a medium/low volume, low pressure pump that runs off the intermediate shaft.
a gas pump would piss off the IP timing advance, blow seals and return lines off of it, as most gas Fuel injection pumps run 65+psi

FWIW, the Cummins (6BT/4BT) has a mechanical lift pump, iirc it pulls the fuel through the fuel filter(s) and feed it to the IP

[R.O.R-2.0]

I've always wondered if you could use a stock VW carburated mechanical fuel pump as a supply pump for the diesel. The engine block even has a place where a fuel pump would bolt up. I forget if there is anything underneath it to actually drive the pump.

there used to be a diesel specific mechanical lift pump.. NLA..

[mtrans]

I've always wondered if you could use a stock VW carburated mechanical fuel pump as a supply pump for the diesel. The engine block even has a place where a fuel pump would bolt up. I forget if there is anything underneath it to actually drive the pump.

By me yes.no VW,it`s only mehanical conections.I use petrol membrane also.

[keaton]

I've always wondered if you could use a stock VW carburated mechanical fuel pump as a supply pump for the diesel. The engine block even has a place where a fuel pump would bolt up. I forget if there is anything underneath it to actually drive the pump.

By me yes.no VW,it`s only mehanical conections.I use petrol membrane also.

huh?

i think what you are saying is VW says no. you say yes you can and your using a gas(petrol) membrane pump with out any issue

correct?

[R.O.R-2.0]

I've always wondered if you could use a stock VW carburated mechanical fuel pump as a supply pump for the diesel. The engine block even has a place where a fuel pump would bolt up. I forget if there is anything underneath it to actually drive the pump.

theres only a drive cam on the older IM shafts..

[rabbitman]

I just pulled the oil pan on my '92 golf and it does indeed have a lobe on the IM shaft.

I've always wondered if you could use a stock VW carburated mechanical fuel pump as a supply pump for the diesel. The engine block even has a place where a fuel pump would bolt up. I forget if there is anything underneath it to actually drive the pump.

Somewhere I have an old diagram of vw's diesel fuel system and it does include a mechanical fuel pump. It was wasn't needed hence the reason it's not used.

To the OP, you don't need an in tank pump unless you plan on running out of fuel often. It's also been proven that it doesn't change the timing at all.

It's all on the forum somewhere..........

[silentdub]

I just pulled the oil pan on my '92 golf and it does indeed have a lobe on the IM shaft.

I've always wondered if you could use a stock VW carburated mechanical fuel pump as a supply pump for the diesel. The engine block even has a place where a fuel pump would bolt up. I forget if there is anything underneath it to actually drive the pump.

Somewhere I have an old diagram of vw's diesel fuel system and it does include a mechanical fuel pump. It was wasn't needed hence the reason it's not used.

To the OP, you don't need an in tank pump unless you plan on running out of fuel often. It's also been proven that it doesn't change the timing at all.

It's all on the forum somewhere..........

Thanks man. I always run my tank on E, it is something that I just do, so I'll keep the pump in place and just wire a switch to it should I ever need to prime it.

[mtrans]

huh?

i think what you are saying is VW says no. you say yes you can and your using a gas(petrol) membrane pump with out any issue

correct?
[/quote]

Sorry, it`s not VW, it`s Fiat