P38 '97 2.5 DSE Manual diesel fuel issue maybe?

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WayneRR4x4

WayneRR4x4

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Its been sat a while, earth strap off as I haven't pinned down my battery drain. Popped the earth back on, jumped in, turned the key... cranking... cranking... and eventually I give up. It did this before, cranked for a while and then started rather lumpily before fully firing up. Swapped out the fuel pump relay, no joy. Someone else suggested the BECM and ECU had dropped sync, but apparently if the lights (injector/engine management) on the dash go off after a short while at ignition position 2 then all is fine there, and that's what happens. Another suggestion is that the non-return valve in the manual primer pump on the fuel line could have failed, I was going to whip this off (couple of jubilee clips apparently) and blow through it against the direction of flow to see if it held, but I'm not even sure mine has one as I cant find it? Am I now looking at changing the fuel pump? A few have suggested using "easy start" in the air intake to see if it fires up, thus diagnosing for sure that it is a fuel issue, but I'm a little reluctant to do that as I've heard that its not a good idea?
 
So, as I thought, mine doesn't have a manual primer pump, so no use looking any more for that lol. Still wary about the "easy start" option, so I will pop the fuel line off and turn it over, see if the pump is actually pumping, if not, then I guess that's the culprit... so, next question, if it is the pump, how do I get at it? I've heard people cutting the floor to access it rather than dropping the tank out, but I'm reluctant to do that, is dropping the tank really that difficult?
 
Depends on how much fuel you have in the tank the less the better. Did mine a while back but ended up cutting the floor as the pump went just after I had filled it up for the month:mad:. Found the measurements on here somewhere. Hth
 
stemac33 said:
Depends on how much fuel you have in the tank the less the better. Did mine a while back but ended up cutting the floor as the pump went just after I had filled it up for the month:mad:. Found the measurements on here somewhere. Hth
Click to expand...
I know I must have around 25 to 30 litres in it unfortunately, just hoping it isn't that.
 
WayneRR4x4 said:
So, as I thought, mine doesn't have a manual primer pump, so no use looking any more for that lol. Still wary about the "easy start" option, so I will pop the fuel line off and turn it over, see if the pump is actually pumping, if not, then I guess that's the culprit... so, next question, if it is the pump, how do I get at it? I've heard people cutting the floor to access it rather than dropping the tank out, but I'm reluctant to do that, is dropping the tank really that difficult?
Click to expand...

On a P reg car the pump will not run whilst cranking but should run when glow lamp is lit.
 
wammers said:
On a P reg car the pump will not run whilst cranking but should run when glow lamp is lit.
Click to expand...
Ok, so, if I read that correctly, I should take the fuel line off, put a bottle of some kind over the end, and then turn the ignition until the glow plugs come on, when I should get fuel pumping, and if I don't, then the pump is FUBAR. If that's the case, do I drop the tank, or cut the floor... although, given that the vehicle is on the road, and I cant get it to a power ramp, getting the tank out might not be possible, unless I can jack it up high enough by degrees to get it on my ramps.
 
The cranked for a while and then started rather lumpily before fully firing up sounds to me like the leak off pipes on the injectors are letting air in and the fuel is draining back, worth checking or replacing and if you do, heat shrink or cable tie the ends it helps then stay put and last longer.
 
kds said:
Well I have been known to cut corners now and then but I would drop the tank .
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Yeah, that's my preferred option too, not keen on cutting up a perfectly good vehicle lol. I'll check to see if the pump is... well, pumping first, if it is, then the leak-off pipes are the next candidate for blame. Any tips on how to if I do have to drop the tank... baring in mind its going to weigh in at 30 kilos+ with the fuel in it.
 
brianp38dse said:
The cranked for a while and then started rather lumpily before fully firing up sounds to me like the leak off pipes on the injectors are letting air in and the fuel is draining back, worth checking or replacing and if you do, heat shrink or cable tie the ends it helps then stay put and last longer.
Click to expand...
I'll check the pump first, if I am lucky and its not that I'll head for the pipes.
 
Decent trolley jack with bit of wood on it to help spread the weight, if you can get it down a little you could maybe siphon some fuel out to lessen the weight, when I repaired the tank frame on my p38 the rear bolts were a swine to undo had to keep spaying them and working in and out so didnt shear.
 
WayneRR4x4 said:
Ok, so, if I read that correctly, I should take the fuel line off, put a bottle of some kind over the end, and then turn the ignition until the glow plugs come on, when I should get fuel pumping, and if I don't, then the pump is FUBAR. If that's the case, do I drop the tank, or cut the floor... although, given that the vehicle is on the road, and I cant get it to a power ramp, getting the tank out might not be possible, unless I can jack it up high enough by degrees to get it on my ramps.
Click to expand...

Well if the fuse is sound the relay is working and the glow relay is working yes. Look in the tech archive for my description of how to power the lift pump.
 
put a non return valve in to start also change the fuel pump in tank wont cost the earth honest o change fuel filter bet that's half blocked
 
Have you checked your glowplugs?from cold when it starts, does it sound like only a few cylinders are firing and then eventually all cylinders fire up?
Does it chuff a bit of black smoke untill it's firing on all six?;)
 
Drop the fuel filter to do the pump test and check the filter for black slime. Pulling the fuel line tends to result in the union breaking.
If the fuel pump & filter are OK, I'd bet it's glow plugs.
 
Datatek said:
Drop the fuel filter to do the pump test and check the filter for black slime. Pulling the fuel line tends to result in the union breaking.
If the fuel pump & filter are OK, I'd bet it's glow plugs.
Click to expand...
New plugs installed recently (sub 1000 miles), it starts if you use easy start in the air intake, but stops when you stop spraying.
Touching the fuel lines near the tank, no indication (vibration) of anything working. The clear fuel line from the filter towards the engine has large air bubbles in it, and when the glow plugs are on, no fuel running through there, nor when its cranked. I'm thinking pump.
 
WayneRR4x4 said:
New plugs installed recently (sub 1000 miles), it starts if you use easy start in the air intake, but stops when you stop spraying.
Touching the fuel lines near the tank, no indication (vibration) of anything working. The clear fuel line from the filter towards the engine has large air bubbles in it, and when the glow plugs are on, no fuel running through there, nor when its cranked. I'm thinking pump.
Click to expand...

Did you not read posts #5 and #14? Not much point giving info if you don't take any notice of it is there.
 
Last edited:
WayneRR4x4 said:
New plugs installed recently (sub 1000 miles),
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Have you checked they really are on? There's a big fuse in the EMS box behind the battery.

WayneRR4x4 said:
The clear fuel line from the filter towards the engine has large air bubbles in it, and when the glow plugs are on, no fuel running through there, nor when its cranked. I'm thinking pump.
Click to expand...

Could be loss of sync on your car. Early ones just crank and don't fire. Cannot remember if the lift pump runs when it loses sync but the FIP won't let anything move. If you loosen the fuel filter and turn the glows on then (assuming fuses and relays are working as they should) fuel will **** out from the filter into the ice-cream tub you just put there to catch it.
 
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