I have the dreaded lack of acceleration (& now worse) following a constant speed run on my new 1998 Marea 125td weekend. At first declutching allowed me to accelerate but now the engine just dies & REALLY takes some restarting.


I've read all the threads around this problem & so far I've checked all the pipes from the tank & blown through them all, remade all the connections. I've renewed the banjo washers to the fuel filter & replaced the (new) filter with another new one. New pipe from filter to injection pump.Waggled all connections from accelerator pot through loom to pump.
Made no difference

I've checked all the air pipes for splits & renewed the air filter. The old MAF had been broken by the bloke who owned the car before me(I've only had this three weeks, having been tucked up on Ebay), so I got a new non-Bosch pattern from Ebay.
Made no difference, either connected or not.

I blocked the EGR pipe on the inlet manifold, then tried cleaning the EGR valve itself, checked that it moved freely. Renewed pipes to the EGR solenoid, tried another EGR solenoid from a TD75(same FIAT part) from a scrappy. All made no difference.

Car has got progressively worse thorough all this effort & now can be hardly started hot or cold. Today going to work the car coasted to a halt three times on the open road injection light sometimes on then off again. Restarting took 10 secs at least on the starter before finally coughing into life. Coming home 22 miles, ditto, finally the car would only run for 5-600 yards after each restart. The poor starter must have been glowing!
At least the car is back at home, but where can I go from here? :bang:I'll try to get a Bosch MAF from a scrappy on Sat ( same on Astra 1.7 TDI's apparently & the Bravo 100TD), but this hard starting is troubling me.
Reading the manual, one thing has occurred to me - I can hear the clutch pedal switch clicking when pedal is pressed, but I can't hear the same with the brake switch, though the brake lights ore OK - could the brake switch be at fault - should I hear the switch click & if so is it adjustable?
Second thing is that this only started when the car got up to running temperature, before that when cold it would zoom away in first & second gear, which is all I can use round here for three or four miles. Could it be a duff temperature switch?

could be turbo problems. do you feel the lunge when it unleashes its boost?

could be compression problems. a quick compresion test would tell you a lot about the health of the engine.

jug said:

could be turbo problems. do you feel the lunge when it unleashes its boost?

could be compression problems. a quick compresion test would tell you a lot about the health of the engine.

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Well I could feel the boost when it was running! I could clearly hear the slight whistle & certainly the car felt fast as it accelerated in first & second, which is all I can manage in the lanes near here. I have to drive at least two miles before I can open it up & by then the engine was warming up. I then had the (sadly it seems) classic TD125 problem of no acceleration unless I dipped the clutch first.
Yesterday after changing the fuel filter (again) I let it idle for 20 mins, which it does nicely with no untoward noises. I can rev it up to 4000 OK, but if I try to hold constant revs, then it will falter & if I try to hold say 3000 rpm it takes more & more accelerator input, until the engine finally fades & stops. It is then almost impossible to restart.
I'm going try a new rpm sensor tomorrow, though I think that'll be £36 wasted but I'm now getting desperate. FIAT dealers are a no no around here, so I'm not going to shell out £66 for a diagnostic since they've told me it might only diagnose 1 fault per session!

if you replaced the maf, and it made no difference connected and disconnected, then that one may be bad aswell, never trust ebay like that, had the same issue on my stilo, so spent a bit more from another motor factors and it was fine

what the hell do they mean "1 fault per session" . Ask to borrow the Examiner, they must be making f**k all use of it . Anyway, It does sound like there is a fuelling problem, if its stalling when revved like that. maybe you need to verify that it is not pulling air anywhere, maybe try putting a piece of clear pipe in the return line from the pump to see if there is any air getting in (watch for air bubbles). Also, disconnect an injector pipe to verify it is getting diesel on cranking..

stylers said:

what the hell do they mean "1 fault per session" . Ask to borrow the Examiner, they must be making f**k all use of it . Anyway, It does sound like there is a fuelling problem, if its stalling when revved like that. maybe you need to verify that it is not pulling air anywhere, maybe try putting a piece of clear pipe in the return line from the pump to see if there is any air getting in (watch for air bubbles). Also, disconnect an a injector pipe to verify it is getting diesel on cranking..

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I agree it FEELS like a fuelling problem, I like the idea of checking for bubbles in the return line - I'll definitely try that & post results.
Following a new RPM sensor, which has made no difference, I'm now stumped!

OK Stylers thanks for the suggestion, I put a bit of clear tube in place of the leak-off pipe from injector 1 (with the electrical timing sensor on it) back to the pump return to tank connection. I can clearly see air bubbles accumulating in this & travelling back towards the pump return. So... does anyone have a suggestion as to where to look first for the source of this air?

try bleeding the fuel system first. if it happens again then you know you have a problem.

It would be hard to tell exactly using the injector leak off, better to try and put it either in the pump feed or return between the filter. but at least if there is diesel coming from the injector leak off they probably are getting fired. but undo one of the injector pipes also to make sure. Is there even any sign of exhaust smoke when cranking over now ?? And is it turning over fast enough ?. starters are very easily killed nowadays from continuous cranking..

stylers said:

It would be hard to tell exactly using the injector leak off, better to try and put it either in the pump feed or return between the filter. but at least if there is diesel coming from the injector leak off they probably are getting fired. but undo one of the injector pipes also to make sure. Is there even any sign of exhaust smoke when cranking over now ?? And is it turning over fast enough ?. starters are very easily killed nowadays from continuous cranking..

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I haven't tried for a day or two now, too much on in the evenings. I've got some 8mm clear tubing, so I'll try that for the steel-filter hose & the filter- pump hose & see where I get. I've been using the wife's Bravo HGT for work, but she's working tomorrow, so I'll have to pick up my daughter(20) tomorrow night in my Lada Niva - she's going to love that:devil:!

Lada Niva ? - I thought the russkies took all them yokes back where they came from

stylers said:

Lada Niva ? - I thought the russkies took all them yokes back where they came from

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There's quite a contingent left in the offroader clubs. Parts available via a great bloke in Cumbria ( last year new master cylinder £8 +VAT & carriage = £14 delivered next day) I use mine for shooting at weekends It can really knock a road car about carrying a load of pigeon shooting gear down farm tracks & across fields. Nivas are REMARKABLY good as standard off road, & on road have the indirect advantage of making any modern car feel like a Ferrari to drive afterwards!

stylers said:

It would be hard to tell exactly using the injector leak off, better to try and put it either in the pump feed or return between the filter. but at least if there is diesel coming from the injector leak off they probably are getting fired. but undo one of the injector pipes also to make sure.

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Right - today I replaced the rubber pipe via filter & pump with some clear plastic pipe. Sucked some diesel up through the filter & then connected the plastic to the pump. Car started fine but loads of air being pulled through the filter. Since I've had the filter & diesel heater (which is sandwiched between the filter & the filter head) apart & fitted a new filter I was sure there were no problems with the filter ( new washers on the banjo too.) So I cut the pipe off the banjo & off the steel feed line & replaced that with clear plastic too. Result was when the car was running, I could see loads of big air bubbles being drawn up from the feed line, from which I deduce there must be an air leak somewhere between the steel feed pipe & the tank. Agreed?

The nylon pipe at the top of the tank has a snap on connection to the stub at the top of the sender unit. Both this & the stub SEEM OK . I refitted it with a good smear of rubber grease, still getting air in somewhere. I've removed the sender unit & pickup pipe from the tank & again this seems OK - so where is the ****ing air coming from? Has anyone had one of these in-tank units go wrong - is it worth me getting the tank unit from a scrappy, in which case I'll also get the snap connector & nylon line as far as I can.

The front end of the nylon pipe joins with a steel pipe at the bottom of the engine bay where it runs up to the bonnet area , then a rubber pipe (which I replaced) to the filter. All these seem OK - I've removed the nylon from all the clips under the car & everything seems fine; the connection to the steel pipe seems sound & both the bottom & top of the steel pipe seem OK ( I can't examine the middle portion of this.)

One thing that struck me was that after stopping the car, the air seemed to move back towards the tank, which to me would indicate some sort air leak up around the filter/pump too. Any thoughts on this - I think if there IS a leak there, it's just getting dwarfed by the amount of air coming up from the tank.

I've fitted a non return valve which has at least allowed the filter-pump line to retain some diesel & ensure restarts are OK, but I feel so near to cracking this problem, yet I still haven't got a permanent fix.

Any good tips for finding an air leak?

you do have plenty of fuel in the tank, like the gauge might be telling porkies

leaks in vacuum or air pipes are easy, but fuel lines not so . Those tank fittings never seemed that positive either. you could try rule out the tank unit by putting the ends of the fittings in a gallon can of diesel and see if the bubbles stop. Other than that it would be easiest to replace the whole pipe. Does the pump return pipe on that car go back into the filter housing to heat the diesel ?? could also be a leak there if so..

johnson550 said:

you do have plenty of fuel in the tank, like the gauge might be telling porkies

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Yes - there's a good 1/4 tank there - I've had the tank unit out a couple of times to check & now I think I've sorted it!!
There's a big 17mm breather pipe plus a 10mm connection & an 8 mm connection. I thought the 10mm was the return, since returns are usually larger than the supply ( in hydraulics anyway)& when I blew & sucked it there was obviously a one way valve operating at the foot stopping me sucking. The 8mm connection had no such "feature". Anyway I got my missus to check while I blew the pipes & then found the 10mm was the FLOW. So why the non return valve operating the wrong way then??
I pulled the tank unit this morning & tried the pipes into a container of diesel - result no bubbles!
I now determined to pull the tank unit apart to see awhat was what ( I know there's a diesel Bravo with the same unit in the local scrapyard, so I didn't mind much about breaking it). I managed to wangle out the foot of the 10mm connection to find a piece of rag about 1/1/2" diameter stuck to the bottom mesh & acting as a reasonably efficient flap valve:bang: It was porous enough to allow a small dribble of diesel, but not enough to sustain medium revs. When I blew & sucked the pipe it felt just like a proper one way valve!! Having removed this the lines are now full of diesel rather than air & the car seems to rev OK. I'm just off to refit some proper pipes in place of the clear plastic & feeling a lot happier
Down side, is I've switched the insurance back to my old (completely reliable, but now rusty) Tempra TD estate so I'm not insured to do a decent test drive in the Marea.
I'm sure I've cured the starting & fading revs problem, but I wonder if I might still be left with the acceleration issue I started with?? I'll need a proper road test to check that & I'm not spending another £25 admin fee to swap insurances, at least until the full diesel tank in the Tempra is gone. Still for now, a RESULT!
Thanks for all who helped, this is one for the knowledge base, its pretty easy to pull the tank unit apart & reassemble even though the parts list shows it all as one unit. I could have fixed this in 30 minutes if I'd looked there first!

good stuff.. now you're getting somewhere. Reminds me of finding bits of rag in tank outlets in tractors etc where people used to dip a bit of a rag on a wire into the tank to use as a "heater plug" - by setting it on fire. Bits of rag would end up in the tank and in the engine