Fuel pump relay

shawn62 · Post by **shawn62** » Thu Aug 14, 2008 10:43 am

Okay everybody, what P/N and brand relay are you using for the fuel pump (mounts under the dash by the M/C)? I have tried all of my sources that I have local and I can not find a subsitute. What I found on the internet only has 5 posts and mine has 6. None of my part suppliers can tell me a new P/N so I can buy a replacement. Even my local VW specialist store does not have any info. The classic response I have been getting is "it does not call for a relay". I guess this should not surprise me because when I needed a M/C for my 62 bug the kid at the auto parts store said according the computer it did not need one.

The markings I have on my currently relay is:

311 906 061
30/51 Bosch
332 003 021
12v 10A

GDRBORETIRED · Post by **GDRBORETIRED** » Thu Aug 14, 2008 1:50 pm

Your first line of numbers is the VW part number 311-906-061. The third line is the Bosch number, however it MAY need to be preceeded by a 0 (zero) as Bosch mostly uses 10 digit numbers, again May is the key word as Bosch is not totally based on 10 digit part numbers. If 332 003 021 doesn't get you a fuel pump relay try 0 332 003 021.

shawn62 · Post by **shawn62** » Thu Aug 14, 2008 2:15 pm

I did try using the 2nd set of number but the only thing I found out from all of my parts suppliers was "it has be discontinued" and they could not tell me a replacement. I did find a replacement. I ended up going to O'Reilly auto parts since I know the manager there and we went thru all of his relays that he has in stock until I found something close. It did not fix my problem. I am getting power to the relay when the ignition switch is turned on, the relay clicks but none of the other posts on the relay becomes hot. I know the fuel pump is suppose to only run for 1-2 seconds when you turn the ignition on but I would think one of the posts should be hot for that length of time. According to the wiring diagram it looks like post #87 should be the power for the pump. Any ideas?

raygreenwood · Post by **raygreenwood** » Thu Aug 14, 2008 2:25 pm

You need to look at several things. The timing for the fuel pump "blip" is accomplished via the fuel injection system. I will trace teh path tonight and get back with you in the morning. I can't beleive I can't remember this. The power relay in teh back (teh one either on top of the ECU or under the left hand rear back seat)...which is the identical part # to the fuel pump relay under the dash...may be teh culprit.

And....usually it is the ground wire.
Also check teh ground wire on the one under the dash. Poor ground to the borwn wire with teh ring terminal usually scured under the mounting screw has stopped me many times. Ray

shawn62 · Post by **shawn62** » Thu Aug 14, 2008 8:45 pm

Does anyone have a Type 4 wire diagram that shows the fuel pump and fuel pump relay? I have looked on Type4.org and vintagebus and all the ones I have found does not show the fuel pump or the relay in the diagram.

raygreenwood · Post by **raygreenwood** » Fri Aug 15, 2008 5:25 am

Yes, I have them. I will see if I can scan them in this evening at home. Ray

shawn62 · Post by **shawn62** » Tue Aug 26, 2008 9:13 am

I finally got power to the fuel pump and it is running. Now I am tried to figure out if it is pumping enough pressure. I started replacing fuel hoses and thought I would check the flow in the line going to the engine. I took the fuel hose off (under the rear by the engine) and ran a jumper to the fuel pump. I started getting fuel out of the hose but it did not seem like much. When I put my thumb over the end of the hose the pump built a little pressure but did not seem like alot. Should I be able to hold the hose closed or should I hook everything up and check pressure at the fuel rail?

raygreenwood · Post by **raygreenwood** » Tue Aug 26, 2008 10:06 am

Which side of the hose did you take off? If its the left side hose...which is on the drivers side then that is the return line and not much pressure will be seen there for more than a few seconds.
If you had pulled the right side hose loose....the fuel pump generally will squirt fuel about 1-2 feet with no restrictions. But...put your thumb over the end and in less than a second it will be spraying everywhere.

The pump itself puts out no pressure at all. It puts out volume...and back stops that with a check valve and sealed roller cells.
Its only when high volume comes in contact with a constant restriction (the fuel pressure regulator...or your thumb over the end of the hose)...that it generates pressure.

The safest way to check this is to (a) connect a gauge to the port on the fuel rail. Having correct pressure is not enough. You must have teh volume to maintain this pressure. To check that (2) Pull off teh hose that is coming into the regulator from the passenger side of the engine and run it into a large graduated jar. You should get about 1 liter per minute.
(3) reconnect all hoses starte the car. Idle, then turn it off. The gauge should immediatley drop to no less than about 20-23 psi. It should take about 40 minutes to an hour to drop to about 18 psi. Overnight is should be down to maybe a few psi.
The object is not really to hold pressure forever...though that would be ideal. The object is not to drop down so low that eventually the fuel drains from the lines.
If that happens, that 2-3 seconds that teh fuel pump buzzes when you turn the key....is spent refilling them to full....at "0" psi pressure...instead of taking them from full at "0" pressure ...to about 18-23 psi...which is good starting pressure.

If the system bleeds down too fast you have a bad regulator or a bad check valve in the pump. Ray

shawn62 · Post by **shawn62** » Tue Aug 26, 2008 5:07 pm

If my fuel pump is bad what is everyone using in place of the OE pump? I checked today on a fuel pump and all of my auto stores show it as obsolete.

raygreenwood · Post by **raygreenwood** » Wed Aug 27, 2008 5:47 am

Of course Bosch is nice. You could get a CIS pump...large and powerful, but most need a feeder pump as well. If you install a small feeder pump the Bosch CIS pumps will last forever.
That being said...of the aftermarket pumps...Wlabro pumps are well made and inexpensive. You must size them correctly...and some may need a feeder pump.

The type 3/4 D-jet pump is a hard animal to replace. It was a very well made pump. Decently large. More than enough pressure and volume....but still self priming. Ray

shawn62 · Post by **shawn62** » Wed Aug 27, 2008 7:05 pm

I hate to sound dumb but I am trying to learn FI systems. Most replacement pumps I have seen only have 1 ea inlet/outlet. Do you use a T fitting so the fuel return line can be hook up and if so I assume the T would be on the inlet side/fuel tank feed?