trouble with bosch pressure control valve

[rryan]

hi
Just a quick question about pressure control valves

are the pressure control valves interchangable between between 306 pumps and other bosch pump such as transits etc?

i only ask as i tried upping the IPP by tapping down the cap on the top of the valve(maybe a little to much), which resulted in the injection being far too advanced to drive.
so i took the pressure valve from a spare 306 bosch pump i have and put it in the pump in the car, which then resulted in the car being a really bitch to start (almost draining the battery to get it to start).

thanks

[Mal]

I'm after checking 2 there, one from a Transit the other from a SOFIM 2.8, both the same....

Did the collar come out from the bottom of he valve? It should be flush....

You really need a pressure guage to adjust it properly!

[rryan]

The collar was flush, but will double check again later

Yeah I know I should have a guage, but I thought I would get away with it seeing as thought I had a spare, maybe i was a bit naive to think that they might all be the same.

I did fit one from a 10mm vw pump and it sounded like i had filled the bores with spanners.

[Dave]

Get an IPP gauge as first point of call, they are dead easy to fit too, just off the fuel return. Once you know this things will.be more apparent when adjusting/changing regs.

[anto]

Transit and 306 pressure valves are slightly different.
Take the 306 valve out of the pump and remove the internals by driving the caps/ spring/ circlip etc out of the bottom of the valve and reinsert.
Then set it back to where it was roughly and that should give you a better starting point.
As has been suggested you really should have a gauge to read the pressure although it can be done by measuring the flow of diesel from the return line back to the tank. (90secs of running at 1000rpm should equal 420ml iirc.)

[rryan]

ok cheers guys

will have a go at fitting a guage soon, how would recommend drill and tap (or just drill and weld) a pressure gauge to the return union?

il strip the regulator valve down and re-asemble in the next couple of days when ive got time.

[Dave]

I drilled and tapped a return bolt as you say, easy to swap in/out then too

[rryan]

cheers i will try that

[rryan]

just another quick question
ive re-turned the valve to its standard position, but as i have a few different valves laying about i just wondered if anybody could tell me which ID number the 306 valves have stamped on them?

i think its a number 12 , but i have a 37 and a 03 valve

cheers

[nominous]

I've just fixed the pressure control valve on my Passat. The end had come out, thus reducing pressure thus impacting the performance. Both acceleration and MPG.
Starting is on the button now as well.
I've got the pump in my car and a spare. Both were out the end. In fact the one in the car had come out completely !!

For VAG it's apparently a common problem.
I'll be welding the end in my a spare and refitting so it doesn't come apart again, but will still function for over pressure.

I guess it's always worth checking, if as the passat pump, it just unscrews from the pump with no drama.
If it's sticking out. I'd be tempted to weld it on the XUD...

A piccy (not actually mine, but the one in my car was as left, the spare was the middle and what it should look like on right):

[nominous]

In case of wondering WTF I'm talking about, here is a diagram borrowed from the VE pump guides:



The pressure valve is an odd bolt head with only two 10mm flats (mine both came out with a spanner vertically and a rod through).
it's under the text on this image that says: cold idle screw

If you remove it, clean the area before hand very well to stop crap getting in the pump. I ran a small screw driver around it to get the dirt out.
Check the valve. If the clip is poking out then knock it back in again.

Pump will just get air it, mine wasn't hard to start after refitting. Just a few seconds chug.



From what I read on VAG, especially those revving the balls off it have this issue. Mine is probably due to running a looped return.
Or, potentially just age !!