*Update* Problem with fuel pump relay or fuse board- help!

Hi all,

It's been a while since I was last here- hope you are all well.

I've just had the fuel filler neck, fuel pump, fuel tank and thermotime switch replaced with new genuine VAG items. I was going to replace the fuel pump relay as well as it's been running very hot and had distorted the plastic around the slots for its terminals on the fuse board. However, once I switched it for the new one (also VAG) the fuel pump won't prime, and car doesn't start.

Swap it out for the old one and it works fine. However, it's running so hot I don't want to leave it there. I checked with the dealer and the relay I bought was the correct one (part number 191 906 383c). The dealer had a look at the relay I have in there and it isn't a VAG unit- it's branded Kracker (part number PA66-GF30). They suggested the fuse board itself may be at fault.

Anyone had any experience of this or have any ideas what the issue might be? I don't want to keep trying VAG relays because if my fuse board is blowing them I'm paying for them.

Thanks all.

Are the relay pin outs the same on both relays? If they are then it sounds like a faulty 'new' VAG relay.

there are several different relays available depending on the year/engine managment, could you be a bit more specific about your model of cabby?
I assume its a digifant model based on your sig,m but I'm not too up on what engines the later sportlines got

Hi guys, no the pins on my existing relay and the new VAG unit are different. However, there is only one type listed in ETKA for my Sportline- and this is it.

It isn't a Digi it's K-Jet.

Today I've ordered a relay unit from Crazyquiff- the type he has on the site looks more similar to what I have currently, so I'll give it a bash.

Cheers,

I'm seeing 2 relays listed for a 91 cab with a DX k-jet engine, the one you bought and another one 321 906 059 G, which is listed for chassis number from F 15-G-000 001 onwards.

191 906 383c is a digifant/KR 16v style pump relay, no way that is going to work on a k-jet 8v lump as it is designed to be triggered by an ECU, which the k-jet doesnt have.  You need the older style relay which takes a rev counter input

Mate that's exactly what I needed to know- thanks! Back to VAG then for a swap

Cheers

may want to check against your chassis number though!  could be etka is just wrong on this one, it can be at times. I think the main issue with cabs is they were late enough to have more options for emmissions controls, which prob more common over in germany.  Its deffo a DX code with no cat right?

Yup- DX, no cat and K-Jet.

cool, should use same relay as mk2 k-jet gti up to 87, same fusebox
the only thing with k-jet relays is some have a rev limiter built in, and some do not (rev limiter in rotor arm instead)

Right- got the new relay from Rich at Crazyquiffs (thanks) and guess what? It's running really hot too.

Does anyone have any idea why this relay would run so hot? New fuel pump and thermotime switch have been fitted.

hmm, maybe try disconnecting the wur, to rule that out of the equation. I take it pump isnt making any nasty noises?

Wur? Let me guess… something something regulator?

Nope- you can hear the pump but it's pretty quiet in the background.

sorry warm up regulator, the metal thingy on front of block with 2 fuel lines to it. the electrical plug is for a heater inside it, and runs from the same feed as the fuel pump
its basically a mechanical choke, from cold it might run a little richer than normal at first, but engine heat will bring it off choke eventually

That sounds the same as the thermotime switch (TTS) which was replaced as well. Are they different?

tts is for the 5th injector and is the brown 2 pin switch in the coolant flange on the front of the head

Coolio. I'll go check.

So, unplug the WUR, go for a drive and see if the relay is hot?

exactomundo! not holding out any hope it will make a difference, but at least you'll know its deffo due to pump/wiring or realy and nowt else

It made no difference- the relay is still running hot. The relay directly below it was warm too but that might be just heat transfer. None of the other relays are warm to the touch.
Waddya reckon? Problem with the board?

i wonder if the main live to the relay socket is dead and its drawing all the current from the ign live?  not even sure if thats possible?  
if you check the relay socket one o the big chunky terminals should have permanent 12v, so worth checkin that.
maybe worth checking the lift pump is workingif not the main pump has to work harder to pull the fuel thru, though im not convinced it would work at all in that case as the reservoir would be dry…

hmm actually perhaps its the lifter pump causing the problem, maybe drag it out the tank and check the filter for rusticles?

Main live to the socket is OK- I just checked.

Can I get to the lifter pump from the hatch under the rear bench seat?

The filler neck and tank have been replaced with new items as has the fuel pump so I guess the only thing left is the lifter pump. Does the lifter have its own filter and is it replacable?