306oc - Peugeot 306 Owners Club & Forum
possible bosch pump problem/ no acceleration - Printable Version

+- 306oc - Peugeot 306 Owners Club & Forum (https://www.306oc.co.uk/forum)
+-- Forum: Engines (https://www.306oc.co.uk/forum/forumdisplay.php?fid=16)
+--- Forum: XUD Section (https://www.306oc.co.uk/forum/forumdisplay.php?fid=11)
+--- Thread: possible bosch pump problem/ no acceleration (/showthread.php?tid=31047)



possible bosch pump problem/ no acceleration - simonh - 30-06-2015

Have just re found the love for the 306 after giving it new top mounts, front shortened shocks, powerflex bottom arm bushes, discs, pads, drop links, ball joints, track rod ends, aux belt and tensioner and a full set of rainsport 3s. Was starting to think the next job might finally be to get the gt2056 fitted and the front mount connected but it's just developed it's first engine problem. I'm fairly sure it's the pump but have just about run out of money so looking for advice before I waste any on buying the wrong bits:

It's currently on a K14 and 9mm Bosch pump with a ground lda and the governor mod. Throttle arm has bits ground off for extra travel.

It was running fine then at the end of a journey it started to cut out every time I slowed down. It was really hard to start the next morning but seemed to be running ok when on the move, slightly down on power and running really clean, usually has a haze of smoke (not coal) when on boost at full throttle. I turned up the main fuelling slightly and adjusted the idle but there was a slight lumpiness. Took it for a drive and initial pickup seemed ok then was dying a bit and a fair amount of black smoke. Running fairly rough and lumpy as well

Then another complication gets added to the mix, while trying to diagnose/ fiddle/ adjust pump it suddenly spewed its coolant. Temp gauge was at about 92-93, fans hadn't come on, probably wiring (will go back to that once it's running). Took out thermostat which was stuck shut so replaced that and just topped up with water for now. (Water has stayed completely clean and doesn't seem to be pressurising and no scum in oil so crossing fingers on head gasket.) Started car and it seemed fine.

I then started trying to set the idle etc again. At some point in the process I moved the throttle arm round to try and gain fine control of idle rather than on the max fueling screw. Have done all this stuff before but could I have broken or dislodged anything inside the pump at his point? Couldn't seem to find a good compromise and then the accelerator cable snapped. It's bodged back together for the moment. Don't think that's relevant but trying to remember every stupid thing I did in the hope that someome can maybe tell me if/ what I may have done. At this point the car wouldn't rev and was really smoky.

Gave up for the night and when I started it today it seemed fine again. Drove into the unit no problem but witha low idle (around 600rpm) adjusted idle on the idle screw (not max fuel) and as the car heated up it started getting lumpy again. Was idling but acelerator pedal wasnt working. hought it was slack nut on arm but that was all fine, revs didn't pick up above 1000rpm, again fairly black. Changed the fuel filter and the base of an old filter was under it. must have fallen off and not been noticed. Thought that was the problem, put it back together and it was fine then after a minute or so of idling and light revving the exhaust starter to get smoky, engine started to get lumpy and accelerator stopped working.

That's the stage I left it at tonight. Any ideas where to start and what to check tomorrow would be much appreciated. I plan on keeping this car so it will get whatever it needs, I just don't really know what that is at the moment. I don't think it'd be fair to hand it to a mechanic either since I've messed about with so much stuff.

Sorry for the essay!


RE: possible bosch pump problem/ no acceleration - r3k1355 - 01-07-2015

Could be something simple like air in the system


RE: possible bosch pump problem/ no acceleration - simonh - 01-07-2015

Think it might be the lift part of the pump. If you pump the grenade while holding the throttle open it comes back to life and the revs rise. I'm sure I've read/ seen pictures on here of how to check it and replace seals etc but can't find it. Does this ring any bells? Have read so many pages about stuff but somehow can never find the right bits when I need them.


RE: possible bosch pump problem/ no acceleration - PartyJas - 01-07-2015

That could still be an air leak. Bypass the fuel filter to eliminate that and maybe replace the grenade too.


RE: possible bosch pump problem/ no acceleration - simonh - 01-07-2015

Seems like a nice easy and free place to start, thanks. :-)


RE: possible bosch pump problem/ no acceleration - simonh - 01-07-2015

Started the car tonight and although it was a bit reluctant to go initially it started and then ran fine. Took it round the industrial estate and was pulling fine, not quite as hard as normal but sure that's just because the fuelling isn't quite as high. Certainly felt really healthy. Brought it back into unit to top up coolant and as temp started to rise it spluttered a couple of times but a couple of blips of throttle seemed to clear it. Once it got to 90 degrees the problem was back though, cuts out and then when it does start it just wont rev.

Going to let it cool for a while and see if it's fine again. If so then I think it's safe to say that the problem is temperature dependent. Are there any faults that could cause this?

If cooling doesn't fix it then I'll start by bypassing the fuel filter (which was my planned starting point). Although it may be completely random I don't want to change anything else incase it just confuses the process of elimination.


RE: possible bosch pump problem/ no acceleration - simonh - 02-07-2015

It seems to be air ingress at the filter housing as when bypassed I couldn't get any of the symptoms even when up to temperature. Smooth idle and revving easily. I didn't actually drive it incase it sucked any crap into the pump.

I cleaned and refitted the housing with silicone around the base and all over the white part/ thermostat controller bit near the fuel inlet. Left it overnight then put in another new fuel filter as the seal on yesterdays new filter seemed to have stretched. Started the car and everything seemed fine again till just under 90 degrees on the thermostat when the engine cut out. Restarted buy lumpy idle and no acceleration unless the grenade was pumped. Is there any area anyone can think of where it would only draw air when it's hot?

Next plan is to try an inline filter and see if that cures it. It's never run on veg so I don't imagine it'd be a problem not to have the heater.


RE: possible bosch pump problem/ no acceleration - r3k1355 - 02-07-2015

That little white X on the bottom part of the filter housing is a thermostat to help heat the fuel, could possibly be the source of your problems.

Did you fully degrease the filter housing before re-assembling??
Any trace of veg oil left will prevent the silicone from sticking.

You can rip the white X out, and all the gubbins inside and do the 'penny mod'
Where you basically silicone a penny in place to seal the housing - it provides constant heating for the fuel, and in theory better running on veg as it's always warmed.

You need to remember to silicone the lid on the filter housing too as they often leak there, it means you'll need to leave it all to dry overnight before filling/priming the fuel system but it works a treat.


RE: possible bosch pump problem/ no acceleration - PartyJas - 02-07-2015

(02-07-2015, 11:37 AM)simonh Wrote: It seems to be air ingress at the filter housing as when bypassed I couldn't get any of the symptoms even when up to temperature. Smooth idle and revving easily. I didn't actually drive it incase it sucked any crap into the pump.

I cleaned and refitted the housing with silicone around the base and all over the white part/ thermostat controller bit near the fuel inlet. Left it overnight then put in another new fuel filter as the seal on yesterdays new filter seemed to have stretched. Started the car and everything seemed fine again till just under 90 degrees on the thermostat when the engine cut out. Restarted buy lumpy idle and no acceleration unless the grenade was pumped. Is there any area anyone can think of where it would only draw air when it's hot?

Next plan is to try an inline filter and see if that cures it. It's never run on veg so I don't imagine it'd be a problem not to have the heater.

I ran my old D turbo with an inline filter for 8 months with no issues. That ran on veg oil too.


RE: possible bosch pump problem/ no acceleration - simonh - 02-07-2015

Everything was degreased but I didn't silicone the top. That could be a good shout. Thinking about the thermostat part; as the engine heats up the diesel switches to bypass so effectively gets colder and thicker so any air ingress would get worse. Will put inline filter in to confirm problem and then penny mod and silicone everything else as the standard filter is much bigger.


RE: possible bosch pump problem/ no acceleration - simonh - 03-07-2015

Fitted an inline filter and everything seems good. Car so much smoother than I remember it and much easier to pull away from junctions. Don't know how long the problem's been building for. Just need to set the throttle arm and fuelling up again properly and it's a happy ending. :-)

Can't believe how such a small problem can make the car seem so terminal.

Thanks for the advice.


RE: possible bosch pump problem/ no acceleration - PartyJas - 03-07-2015

Glad you got it sorted.


RE: possible bosch pump problem/ no acceleration - simonh - 14-07-2015

The problems all came back but randomly, and dramatically improved after I added £15 of diesel to the tank on way home. I'd loaned out the car a couple of days before the problem started and it now turns out that it had £30 worth of petrol in the tank so was about 40% diesel/ 60% petrol when I got it back.

Filled it completely (with diesel) and it's just getting better and better. Starts in the mornings, idles smoothly and doesn't try and constantly overheat. Not sure how anyone could possibly think that an XUD9 TD was ever a petrol engine though!


RE: possible bosch pump problem/ no acceleration - r3k1355 - 15-07-2015

Whoops, yea you should just brim the tank with derv to dilute out that petrol.


RE: possible bosch pump problem/ no acceleration - ADV_93 - 17-07-2015

Wind max fuel in


RE: possible bosch pump problem/ no acceleration - simonh - 20-07-2015

Wind in max fuel to help deal with the petrol or just in general? Petrol now fully out the system.