86 VW Jetta Diesel - Fuel pump location?

[bluerain]

We've got an 86 VW Jetta, Diesel, and it appears the fuel pump has died, we're not getting any fuel up. So figure either relay or pump, seems like pump clicks on (my understanding is the relay is the one that times the glow plug wait, and it clicks on/off).

Trying to find the pump, looked in trunk, in the little circular hatch towards the end of trunk on pass side, that just seemed to have the fuel gauge in it.

Looked under, beside the water separator, and nothing, just the box with the drain on the bottom.

Can anyone help out with where the damn thing is located?

thanks!

[damac]

the fuel pump is the injection pump mounted at the top of engine towards front of car. it turns with the timing belt.

the pump has a wire that on ignition opens the valve it connects to so fuel can pass through.

clear hoses and jugs on in/out lines can tell you what the car is doing, hang the inlet up on the hood. you should see good flow with the pedal down and cranking. i have seen pumps start up that don't really show it, i have also seen a pump try and suck backwards.

fuel restrictions can play a role.

there is a water seperator unit under passenger side rear wheel well of car.

fuel filter is in a bracket in engine bay on passenger side. these can also plug up solid so you can't blow anything through them.

so you want to troubleshoot this, right now i would make a rig like i said just to see what is going on.

if you are getting white smoke out pipe while cranking then the pump has power and is letting fuel through.


i have come across more than one ok running car that had plugged vanes inside the pump. crusty varnish, dirt, etc. you can try once you get it running to let it get atf fluid through the system and shut it off for a day, then come back and run some more to help clean things out. but i don't think it can get it all if its truly plugged.

resealing was scary for me but i bought a video howto on ebay and ended up doing it in hours and throwing it back on car. no big deal if you can use tools, vise would help allot.

others in a pinch have thrown and electric pump on the car to keep things moving. diesel pump should be low psi for these cars.

[bluerain]

Thanks.

So, if we put a low pressure electric pump inline that would probably keep the fuel moving?

[Trumper]

You NEED to remove the fuel separator box on passenger rear bottom of car.
The plastic ages, becomes brittle, and allows the fuel system to draw air.....causing the problem you have not totally disclosed.

Remove the box, place a pusher pump (which will free-wheel when not energized) in that space, and get on with your life.

I have one there which free-wheels (I rarely turn it on) almost all the time. The pump helps out to prime new fuel filters, etc. I thought it might help in very cold weather to overcome gelling tendencies.....not so much.

If you wire it direct, there is no harm.

[bluerain]

We pulled the water separator, put in a small electric diesel fuel pump (free flow) and all good. Running smoother than it was before the fuel problem stopped it. More power now than before.

thanks for the answers, helped us sort it out quick.

[Fatmobile]

You should still check the intank screen,.. and remove the check valve in front of the undercar water seperator.
Something might have been causing a restriction,.. if that's the case the pump is just a band aid.

If it's the vanes inside the pump, the electric helper pump is a nice therapy that might actually allow the vanes to get moving when you hit higher RPMs,.. then you won't need it anymore.

[vwtyp133]

The 1985 VW Golf/Jetta diesels, and likely the '86 also, came with an electric 'lift' pump in the fuel tank. IIRC they frequently gave problems & at some point VW just eliminated them. That device could also be a source of restriction if it's dead, as could a plugged-up 'sock' type filter around the fuel pickup inside the tank.