Technical Doblo desperation

[Eastendborn]

I wonder if anyone could advise me. I have a fiat Doblo jtd 1.9 -2005 model. For two years it has been playing up- and nobody can fix it. As I'm a pensioner I can't afford expensive mechanics. It starts up, and then when I'm just setting off it cuts out. The glow plug light flickers for a bit - and I usually wait for this before setting off. If I get past two cut outs- when I'm on a run- it stays ok -doesn't cut out, it can run on and on -as long as I don't switch engine off. (When I get past the cutting out stage I could drive non stop top Cornwall from London). It cuts out mainly when I've gone a few hundred yards down the road. Recently I have started it on the driveway and it has cut out on tick over. When I went to start it again again - it started then died. A couple of times the only way I could get away - was to rev it like a racing car then drive like crazy down the road - then it would stabilize for a bit. It is worse in cold/damp weather. As I said, it only cuts out when I first start up- and it will do that even after an hour of driving – when I switch the engine off. So I try to keep it running once I have been driving for a bit (after the cutting out stage) even if if I am sitting a train crossing for 10 minutes (so as not to switch the engine off and have to go through the cutting out/non start phase again). I am at my wits -end - fed up with konking out on busy roads when all power goes lights/ steering etc. If you could help I would really appreciate it. W.Jones.

 

[Eastendborn]

I wonder if anyone could advise me. I have a fiat Doblo jtd 1.9 -2005 model. For two years it has been playing up- and nobody can fix it. As I'm a pensioner I can't afford expensive mechanics. It starts up, and then when I'm just setting off it cuts out. The glow plug light on display flickers for a bit after starting- and I usually wait for it to go away before setting off. If I get past two cut outs- when I'm on a run- it stays ok -doesn't cut out, it can run on and on -as long as I don't switch engine off. (When I get past the cutting out stage I could drive non stop top Cornwall from London). It cuts out mainly when I've gone a few hundred yards down the road. Recently I have started it on the driveway and it has cut out on tick over. When I went to start it again again - it started then died. A couple of times the only way I could get away - was to rev it like a racing car then drive like crazy down the road - then it would stabilize for a bit. It is worse in cold/damp weather. As I said, it only cuts out when I first start up- and it will do that even after an hour of driving – when I switch the engine off. So I try to keep it running once I have been driving for a bit (after the cutting out stage) even if if I am sitting a train crossing for 10 minutes (so as not to switch the engine off and have to go through the cutting out/non start phase again). I am at my wits -end - fed up with konking out on busy roads when all power goes lights/ steering etc. If you could help I would really appreciate it. W.Jones.

So nobody got any idea?

 

[500e]

Crank or cam sensor ?? do a dump & see what error's are recorded
Remote locking playing up again on my 07 1.9

 

[Eastendborn]

Surely someone in the world has enough car mechanic knowledge to find the fault. This has been going on for over 2 years now- every time I go out I have to put my hazzards on with cars stuck behind me - I've had 3 A.A. men who can't find it- and various mechanics- I wish I had been trained in mechanics then I reckon I could do better than many of the so-called mechanical wizzards around today

 

[polly1234]

check this part out

after 1.9 jtd had the same issue

! discovered a solenoid valve behind EGR, which has 2 vacuum pipes on it, one to the air intake throttle valve or shutoff valve oroverrun valve whatever its called. . Called boost pressure switch, or throttle vacuum solenoid or whatever anyway it wasn't working (12V across the terminal solenoid not clicking and no air flow),so I soaked it in WD40 over night and working great. I refitted it and car is now fully operational again....and has been for a few weeks now.

 

[Eastendborn]

Dump? I assume you mean use a computer to diagnoze. I'm not familiar with modern technology. But thanks- and thanks to you all- I will investigate. As for central locking problem - I took out the fuse on mine in order to lock it manually as it was also giving me grief.

 

[AndyRKett]

Dump? I assume you mean use a computer to diagnoze. I'm not familiar with modern technology. But thanks- and thanks to you all- I will investigate.

With all modern cars almost every aspect is controlled by computer and then any faults no matter how trivial they may seem are logged in the computer.

Sometimes people will plug the computer in and if they don't understand why there are a few seemingly unconnected faults which don't immediately explain the problem then they are stumped and walk away.

Someone with a bit of common sense would, however, be able to put the faults together to maybe point to a common ground point that might have failed or a bundle of wires that might be damaged.

In the case of the engine cutting out it could be mechanical or electrical or both. This is why we are all so reliant on connecting up the computer and checking the fault codes to see what is going on.

Clearing fault codes these days is the modern equivalent of giving the carbs a squirt of cleaner in the past.

 

[bunterboy]

Not sure how much info a 2005 Doblo stores, my Italian mechanic said it wasn't worth checking my 2004 JTD, I think that's what he said anyway. Good luck. My Doblo has been great but starting to play up now.

 

[Eastendborn]

Yes I guess these computer systems are complicated. I must try and find a guy to look at that when I can afford it. Meanwhile I'm hoping a mate will look at this EGR valve thing. I've pin-pointed it down to temperature. I mean when I start it up- I have to keep it on a 1000 rpm at least until the temp gauge is at its highest (between C and H) Then after that it usually doesn't cut out. It's only when I go to get away with out heating the engine out that it cuts out on me. I have changed the crankshaft sensor and checked earths - so now as recommended i will try the EGR valve. Any more advice is welcome.

 

[Eastendborn]

Tonight. I started it up - and kept on 1,000 rpm for 10 minutes. I then was able to drive for 1 hour - 40 miles without stopping and it not cutting out on tick-over. Then I stopped for 20 minutes and upon starting up - engine cut out. It did so 4 times after just turning it over - and so I had to step on the gas whilst holding the key in starting position whilst kicking it up to 4,000 rpm (still maintaining key in turn over position - for if I let key go on initial start up it would die) So I held 4,000 rpm for approximately 1 minute and was able to then drive away. It did it again just a little way down the road when I had to stop at the junction. Only when engine is at its hottest does it stay normal (not cut out) Getting really sick and tired of the crock now.

 

[Eastendborn]

Any further advice appreciated

 

[polly1234]

did you check that solenoid i told you about a few weeks ago?
also check MAP sensor near to EGR valve.....one of ours was blocked with oily mess, new one sorted that.

 

[Eastendborn]

Hi I'm about to check egr valve and solenoid thanks for your help.

 

[Eastendborn]

Thanks I will post on here outcome of trying solenoid and egr valve

 

[polly1234]

these modern cars have sensors everywhere....
ahhhhh the old days of points, su carbs and spark plugs or diesel pumps and black smoke.

 

[AndyRKett]

Tonight. I started it up - and kept on 1,000 rpm for 10 minutes. I then was able to drive for 1 hour - 40 miles without stopping and it not cutting out on tick-over. Then I stopped for 20 minutes and upon starting up - engine cut out. It did so 4 times after just turning it over - and so I had to step on the gas whilst holding the key in starting position whilst kicking it up to 4,000 rpm (still maintaining key in turn over position - for if I let key go on initial start up it would die) So I held 4,000 rpm for approximately 1 minute and was able to then drive away. It did it again just a little way down the road when I had to stop at the junction. Only when engine is at its hottest does it stay normal (not cut out) Getting really sick and tired of the crock now.

Everything you describe tents to point to a high pressure pump issue.

If you look at any forum for any modern diesel car, hot start problems are almost always caused by the high pressure pump not being able to produce enough pressure once they have warmed up and parts heated and expanded as well as the warmer fuel being thinner.

More revs mean more fuel pressure and so by doing what you’ve found you need to do, warming the engine by high revving for the first few minutes or else it dies, you are increasing the fuel pressure to keep it going.

The pump is an expensive component, so I’d still get it plugged in to confirm, before you open your wallet for a new pump.

EGRs can be a pain in the arse but they don’t generally cause problems. With starting they just make the car run like a dog.

 

[jackwhoo]

If it has jtd engine.
Make sure the electric lift pump in fuel tank is working and keeps working while engine hot.
Multi ecu scan software and cable.
Read for any stored fault codes.
Read pressure in common rail while cranking on starter check it's sufficient.

 

[turbozed]

Sounds suspiciously like a tank pump issue. I had a rover 75 that did the same. That was the tank pump. Can you hear a quite wirring coming from the rear of the car when you turn on the ignition? It should stop after about 10 - 15 seconds.

 

[Eastendborn]

Andy regarding your qoute "If you look at any forum for any modern diesel car, hot start problems are almost always caused by the high pressure pump not being able to produce enough pressure once they have warmed up and parts heated and expanded as well as the warmer fuel being thinner" Did you mean to put the word until - instead of once? (It would make sense that once revs were high and engine warmed up- fuel would be thinner and pressure would feed it through better) Thanks W.J.

 

[AndyRKett]

Andy regarding your qoute "If you look at any forum for any modern diesel car, hot start problems are almost always caused by the high pressure pump not being able to produce enough pressure once they have warmed up and parts heated and expanded as well as the warmer fuel being thinner" Did you mean to put the word until - instead of once? (It would make sense that once revs were high and engine warmed up- fuel would be thinner and pressure would feed it through better) Thanks W.J.

I might not have explained it very well.

When you start a diesel car, the starter motor has to turn over the engine which In turn spins the high pressure fuel pump, creating the pressure to start the engine.

In modern diesels the fuel is injected, in the middle of the compression stroke and timed to spontaneously combust at the top of the power stroke.

To inject the fuel at this stage the pump needs to generate huge levels of pressure to overcome any back pressure from the compression of the engine.

When starting the engine no matter weather the engine is cold or hot, the pump will not generate enough pressure to push the fuel into the engine at the right moment, the engine will turn over much slower on the starter than once it’s running so lower pressure still.

When the engine has been running a while and the engine and pump is nice and warm the components in the pump and in the injectors, is likely to have warmed and expanded slightly creating a bit of extra pressure, however stop the car and the heat will quickly dissipate, and any cumulative fuel pressure from the higher engine speed will quickly pass back to the tank via the fuel return pipe.

This maybe why you are struggling to get it started, even if it’s been running ok for an hour or so.

I hope this all make sense, reading back what I had written I can understand the confusion