Hi all, 8year old CX80 with 2200hrs. Serviing it i thought i would drill through the inline filter and make it redundant, bound to be a problem one day, bet the dealer would want £££'s for a new one.  My 5130 doesn't have one ,yet bigger engine- more fuel flow. Only has one main filter, the same as CX80

Next day as expected main fuel fuel blocked through disturbance, replaced it ok.

But now when working, the revs keep fluctuating 100rpm, quickly- as in down 80rpm, then up a 100,all in a split second with a gap of several seconds before next episode, starts and runs fine at low to meduim revs.  But spreading fert it is a real pain!

The question!

Have all the disturbed bits got in the lift pump and spoiled it? (the inline filter is before the lift pump!)

What are the symptons of a faulty lift pump? I can't dismantle it, it's all riveted up. the hand primer works but not very forceful, won't spirt at the filter head

 Thank you in advance for all your wisdom :-)

 

update, my friendly neighbour suggested air line on the lift pump, i took off and blew through, it did make it better, for a short time only

 Hi, It souds like its sucking in air or making air in the fuel line/system. Manually work the lift pump  (take it off, if its on the engine) with the pipes off see if it pulls a vacuum and builds a pressure? block the inlet and work the pump manually, leave it for a few seconds and see if the vacuum is still there when you remove the blank from the pipe. Do the same on the outlet.

You could try flushing engine oil through the lift pump. There may be a small filter in one of the fittings going into the injector pump, it may be partially blocked. You have all the fittings back in place and have no air leaks? Check the sealing washer on the new filter and also check the pipes/fittings on the filter casing for a partial blockage or air leak. Blow back into the tank with a LITTLE air pressure.

Not the easiest thing in the world to sort out.

 

Wow,, filters eh, who needs them???

Well, in my experience I find if you replace them at sensible intervals you can expect to have few real problems. I'd way rather change my filters than upset the main fuel system with the rocks & water that filters catch. Ever thought how much an injector pump costs + labour + inconvenient downtime??

thanks for your suggestions, tried them all. Eventually took off lift pump to buy another and thought nothing to loose if i have a look inside, the normal dome bit that covers the rubber diaphram is usually held down with screws so couldn't take to bits. However, the inlet port had a graet big 27m nut, the only bit that could come to bits. Guess what? there is a bowler hat tiny filter in there that was well bunged up with gunge :-)

 

It's a shame the hand book doesn't tell you this. My neighbour who works on Volvo trucks says the trucks are terrrible for the filter IN the tank blocking. I asked why dont they put an inline filter where you can get at them? he says it's to stop idiots drilling through them :-(

thanks for your help

You should really fit a new inline fuel filter as it picks up any big bits of crap and stops it getting jammed in banjo bolts on the filter head. Also 5130's have a filter sock on the end of suction pipe inside the fuel tank.

 

thanks for that, have now fitted an inline filter, £2.80, it's only 8mm instead of the 9mm hose it should be so a little restricted before we start! got it from a motor factor

the 5130, it's a 1997 and the filter in the tank has never been checked,is it easy to do or do you have to take the tank off? might be best to replace it with a easy to get at inline filter?

 Hi all, Great you found the problem with the lift pump. I think that inline filter could be for petrol? You may find it clogs very quickly, have one as a spare anyway.

Good idea to put a filter on the 5130 where you can change it easily. You probably will have to take the outlet pipe out of the tank to check the sock filter.

To get to the filter in the tank you need to remove the seat to get access to the fuel sender in the top of the tank. Unbolt the sender and pull it out of the tank which can be a bit tricky. Just remove the filter sock and fit an inline filter on the rubber hose before the lift pump. Hope this helps.

Thanks Devon, Would never have thought of getting at it from within the cab! I would have had the gearbox out first!!  Sounds like a cunning plan needed, given that i haven't had a problem with the 5130 yet and its age 1997 P reg, you think the time spent doing it would be worthwhile, or if it isn't broke don't fix it? seats can be a swine to get out...

thanks again for top tip

5555:

or if it isn't broke don't fix it?

 

I wouldn't touch it unless it's causing probs.