300tdi injector timing

bigM · Gate Opener Joined: 14 Apr 2010 Odometer: 30

hi guys,
just fitted new timing belt and second hand injector pump to discovery.starts fine but engine revs erraticaly around 1500 rpm!!not as much power when driving up the road and it stalls when dropping from high revs.Is this a timming issue or something to do with the second hand pump?
Any help greatly appreciated
thanks

Hooli · Posted: Sun Sep 04, 2011 7:42 pm Post subject:

Did you time it properly when you fitted it all? if so it shouldn't be timing.

How long has it run? I used to have to let my 200TDi idle for about 5mins to bleed air out the system if I'd had anything apart, else it did what your describing.

Scrooge, E. · Guest

I agree with Hooli - have you bled all the air out of the fuel system?

bigM · Gate Opener Joined: 14 Apr 2010 Odometer: 30

Yes the timing was done by the book and the system was bled. Left runnung for about 20minutes and driven up the road a bit.Still the same.........erratic at 1500 rpm and cutting out when dropping from high revs

Hooli · Posted: Mon Sep 05, 2011 6:23 pm Post subject:

In that case I'd suspect the pump.
Could be worth checking the diaphram under the square cover for splits. It adjusts the fueling according to the boost pressure which I seem to recall comes in about 1,500rpm. Just mark it before you remove it so you can put it back in the same place.

bigM · Gate Opener Joined: 14 Apr 2010 Odometer: 30

ok i will try that and report back . If this is the case , can i switch it with the one from my old pump ?

Hooli · Posted: Mon Sep 05, 2011 7:06 pm Post subject:

I can't see why not. Just try to get the diaphragm rotated to the same position as it was on the pump it came out of to keep the fueling as standard - provided neither car has been tweaked of course.

bigM · Gate Opener Joined: 14 Apr 2010 Odometer: 30

Thanks for the advice.......
Problems have worsened now . mate revved the t**ts off it and now the engine has developed a loud knock , so something has given up .cant decide if its comming from the bottom or what. Sounded at first like if you took the exhaust off and ran it.
will get a pal who knows a bit more about bearings etc to have a listen tonight

bigM · Gate Opener Joined: 14 Apr 2010 Odometer: 30

ok knocking sorted out , tirned out to be a locknut had worked loose allowing number one valve to adjust
Ok , so , after much cleaning and running up and down the road the pump is behaving its self now and the revs have settled.
Only thing now is it doesnt seem to have the same poke from take off ???
Is there an adjustment i can do on the pump??
Thanks again

giggleberry · Posted: Thu Sep 22, 2011 8:05 pm Post subject:

try adjusting the diaphragm you were talking about earlier , mark it and turn a little at a time , if the power drops turn it the other way etc . to much fuel though and it will smoke .

Hooli · Posted: Fri Sep 23, 2011 10:16 am Post subject:

This is from memory a few years ago but I think it's right.

For poke from pulling away before the boost kicks in then tighten the screw in the centre of the the square cover that goes over the diaphragm.
This alters the base fueling position of the 'cone' to a richer place before boost. The boost then pushes down on the diaphragm & richens the engine as the air it takes in increases.
The max power screw in the back of the pump does exactly what it says. I found on my 200tdi that I hardly needed to move the diaphragm after winding the centre screw in a turn or so. But I did need to tweak the max power screw in a load as I was getting to full power at 1/2 throttle!