RPM sensor is the crankshaft sensor. It's located near the oil filter, in the right back of the engine below the turbocharger.

 

ok so 12 months on and I'm finally going to do something about it!

Changed fuel filter 2000, miles ago and the hot start problem is back. I finally managed to get the knack of the key dance and sure enough I get code P0340 (upto 30 times) which I understand is the crankshaft sensor, or the wiring to it etc. So I think Joker2cv was right about the crank sensor

So I will first check the crankshaft sensor wiring and then replace sensor if I find nothing.


So my questions are:

Does anyone know if it is worth cleaning the crankshaft sensor? I only ask because I recently fixed a starting problem on a Renault Clio just by cleaning the crank sensor, it wasn't that dirty, but cleaning it fixed the problem.

What is the best way to remove crank sensor? From above, take wiper tray out etc or from underneath? probably worth mentioning that my arm is not the diameter of a babys' and that I only have one elbow joint, not the three it looks as though I will need!

Any idea why changing the fuel filter solves the problem short term? This bugs me so much that last weekend I unscrewed and refitted the same filter (2000 miles/ 6 weeks old) to see if that gave the same short term fix, it didn't, but when I unscrewed the drain tap at the bottom there was a hissing noise which I assume was air being sucked in. I have never noticed this before. I dont think there should be any vacuum in there? I think I have more than one problem?

I would appreciate any views/thoughts you may have

Thanks

Rodger

 

Essentially a busy but careless junior fitter doing the mundane service while listening to the radio and chatting to his mates forgets to oil the ring or nip it tight after bleeding through or whatever, and :

- fuel filter not tight, and ;
- fuel 'runs back return'
- air leaks into fuel line

However if its only providing a short and not long term fix it is as you say not your only problem. In my case it was also the drain tap that was left loose or had 'worked loose'.

 

I'm not too familiar as yet with this engine, but many diesels have TWO fuel filters, one near the tank filtering out larger crud particles, and another to filter out micron sized particulates nr. the HP fuel pump. It's important to make sure with these fuel injection systems which work at around 25,000lb/sq." that there are no particulates getting to this very high pressure fuel pump which is "on" all the time.
The other thing I'd check with your high mileage is the fuel tank which MAY need to be removed and steam-cleaned.
Cheers,

Leedsman.
p.s. the fuel lines might need a blast-out before the HP pump too.

 

Another thought -- the lift pump raising the fuel from the tank to the HP pump could be almost worn out? Again, I'm guessing here....

Leedsman.

 

Thanks Leedsman/Qinteq

I think that upto 2004 (ish) there was a fuel filter (cannister type) near the fuel tank and a lift pump and that from 2005 the filter was moved to a spin on type on the front of the engine block and NO lift pump! The HP pump does all the work!

I'm fairly confident about the health of the HP pump, it checked out ok when I had injector problems.

Theres a thread somewhere on this forum, dutch guy I think, who had stalling problems due to algae growth in the fuel system, going to try and find that.

Anyone used "Grotemar" (spelling?) to get rid of algae? May try that first.

Anyway, I'll let you know what I find.

Thanks again.

 

Symptoms
Cold start, don't wait for glow plug lights to go out, or reluctant to start, been like this since new.

Hot start, Can take a few attempts, but new filter would solve it for a few thousand miles, this got worse until new filter made no difference.


Ok..I think it's now fixed, so here what I did

1. Treated with Grotomar, no change.

2. Still had code P0340 but I really thought it was fuel related not crankshaft sensor, bought sensor but didn't fit it.

3. Took the fuel heater off and saw some mild burn marks, put some epoxy into the plug socket to "seal" any small holes. Worked a treat, hot starts no problem...for a day. Then worse than before.

4. Bought new filter housing, plug and socket is much bigger and can carry more current. I noticed that the burn marks had got much worse, the plug had almost burned away (see attached photo)
Worked a treat, hot starts no problem ...for a day. Then much worse than before, engine now struggles to start from cold and cuts out under moderate load, will restart with difficulty.
Now getting P1130 codes, lots of them on the key dance.

Well, at least I had a hard reproducible fault.

5. Fitted new relief valve (at the end of the fuel rail) and problem solved...so far...thats 5 weeks and about 2 thousand miles.
Hot start no problem.
Cold start has changed, now if you wait for glow plug light to go out it starts much easier, just like it should. It has never done this before, from new.

What I don't understand is why new heater/pump housing made the problem worse. This new heater pulls 9.5 amps so it over 100 watts (I never measured the old one) I can only imagine that if the relief valve did let air into the common rail then the fully working heater heats the air, which expands and pushes the fuel away from the injectors and the air is compressible so the pump cant get upto pressure and throws a P1130. What do you think. Still cant understand why a new filter used to solve the problem for a while.

The engine definately idles much smoother (bottle of water kept in centre console cup holder has no ripples on the surface, bit Heath Robinson ...but!) also seems to drive better but that could just be me.

Anyhow, I think its fixed, only took me 18 months! Hope this helps someone out.

 

i found out your thread only now, but your problem was air in the fuel system, my 2000 voyager had the same problem, after losing much time with it, i changed relief valve and problem went away.
but i am glad your problem went away too.

 

We could do with a "reference" section on this website outlining positive cures for these kind of really awkward faults that seem to take weeks and months to fathom. Not so much 'frequently asked questions' as 'frequently experienced faults'.
Anyhow, an excellent result here...

Leedsman.

 

My Grand Voyager 2.8 CRD limited experienced similar problems summer of 2012. Google suggested that it could be the fuel heater sucking air, but I changed the fuel heater and the problem got worse every week.

At the end, the car would only start if I primed it and ran into the car to start it. I would normally not stall while running.

I had my car in our local Chrysler shop (Nardo bil) for 3 months that autumn, and their only suggestion was to replace the whole HP-pump.
Since they could not guarantee that they had pinpointed the problem, I told them not to do it. At one point I actually agreed to an offer to change the pump and timing belt belt as a combined job, but they called me back a few hours later and told me that the HP-pump was not 1100 USD as first quoted but, close to 3000 USD, after their generous discount! I told the incompetent fools to go .... themselves and picked up the car.

I finally took the car to a local Diesel-"professor", and he logged the pressure in the rail for an hour or so. He said the pressure dropped slightly every now an then, but not so much that it would stall while running.
He suggested that he should order both the relief valve and the Fuel Pressure Regulator to see if it improved the situation.

And it did, it turned out to be the regulator in my case. Slightly cheaper fix than changing the HP-pump....