NickWhiteKent

New Member
Hi all,

First thread!

Took my Series III diesel on its longest run since the full engine rebuild earlier this year. Been using the car a fair amount but for nothing more than 15-20 mile trips, but enough I was confident it was pretty solid.

Did a 50 mile (mostly motorway) trip at the weekend and she ran well until then end of the leg. Just leaving the motorway and noticed it “running lumpy” slightly in town traffic. Problem got progressively worse until she started cutting out. Just before it cuts out I notice the revs increase slightly for a second or two.

Once pulled over and left to rest for 5 minutes it would startup again OK but problem reoccurred after a few more minutes. Luckily I got to my destination OK. On the return leg, again, she ran OK. I made sure not to push the engine too much, trying to keep it moving along at 50mph at half throttle. Still at the other end of the leg I had the same problem but managed to limp home.

Now, when I had the rebuild done, the only thing we didn’t change was the main diesel pump. This explain the light smoke on cold startup but otherwise the engine runs very well (or so I thought). Now I’m thinking this is the likely culprit for my current problem, perhaps once fully warm it is exhibiting this problem?

My rebuild covered pretty much everything, new liners, pistons, valves, injectors, pretty much full strip down and rebuild. I’m reluctant to think the problem could be anything other than an ancillary as it just runs so well otherwise.

I’d be interested to hear anyone’s thoughts or steps to further diagnose. And if the pump is to blame, best place to go for a recon unit? I do have another spare (attached to a S**tter old engine I acquired) but wouldn’t trust it to be any better than the one I’m currently running with.

TIA for any thoughts?
 
by any chance did you use any britpart (****e part to many) in the rebuild, if you did id rekon theyve got sumit to do wif it
?
 
After cleaning some crud from the pickup tube filter in the tank, and taking a long flat-out motorway test drive for an hour I thought I cured this. However, after a 2hr trip back from East Anglia, with half a mile to go she started playing up again. There was ~1/2 a tank of new clean diesel in her at this point.

The outward leg of the journey the day before she didn't miss a beat with a briming full tank. The pickup assembly and sender gauge are relatively new.

I'm not sure if the isssue is heat related or fuel tank levels, or what now.

Very confused, any insights welcome.

Oh, no cheap-o parts were used in the rebuild either, only pukka gear.
 
Does it have an electric stop and if so is the connection nice and tight.
Why not brim it again and if the problem goes away its got to be something to do with the pick up pipe.


Lynall
 
This may be way off the mark but years ago I had a problem with an old Anglia. It would drive 30 miles then splutter and cut out. Left for 15 mins, it would go again with no problem for next 30 miles. Turned out it had a cracked manifold, when it heated up the crack widened, drawing air. Left to cool down the crack closed. Dont know if this would affect a diesel though but could be a crack in the head.
 
could be air leaks in the fuel system, checking all joints might help as they can be hard to pinpoint
 
Thanks guys. No electric stop, it's a choke type cable stop. I had the whole engine rebuilt just a couple of thousand miles ago. I'm pretty sure it's solid. I'm thinking it must be an air leak issue or a problem with the main injector pump once very hot. I'll have to recheck the fuel lines between the injectors, the stuff from the tank to the engine bay is all fairly new.

Given it generally takes +1hr flat out motorway miles to get the issue it's difficult to test.
 
My money would be on fuel starvation and/or air getting into the system.

I had similar issues on my 300TDI powered series 2 88".

On investigation I found fuel pickup pipe was restricted, and air being sucked in. Also muck was being sucked into the lift pump. This caused the lift pump (and in turn the main injection pump) to drag in air.

Engine started great when cold, and ran lovely until you were motoring along and suddenly lost power. Into "limp mode" where vehicle would only move at walking pace and low revs.

I replaced all the fuel pipes with clear hose, which confirmed air ingress. Also widened the fuel pipeup inlet and added a cheap inline filter before the lift pump. Lift pump was knackered so replaced that too.

500miles or more on clock now and seems sorted.

Lack of fuel, air and mechanical failure are about the only things that can stop diesel engines.
Fuel pipes that are warm/soft will also tend to let air in more readily.

Mark
 
Thanks Mark,

That makes a lot of sense. I had a fuelling problem when I first got her. Had all the lines replaced, the pickup assembly in the tank, and the lift pump also. I knew it was an air intake problem then as I had a section of clear hose in place but this was all cut out when it was replaced. Perhaps I'll add a section of clear hose again to verify.

Given the (cheap) cost, I'm half tempted to get a new tank to slap on her. Not had a look too closely on how to do that but can't imagine it's too much of an effort? This way I'll know i'm not picking up 30yrs of debris.
 
Not sure whether you've got a LWB or SWB, but either way tank should be easy enough to drop out

Not sure on cost of tank (and what you consider cheap).
I think I'd be tempted to drop your tank out and give it a really good swill out. Depending on what comes out, and the condition of it,it might be worth putting some POR15 tank sealer in it. Also (if you haven't already) ditch the filter gauze on the pickup pipe and put a cheap replaceable inline filter somewhere before your lift pump. I'd recommend locating it either under the central seat box or in the engine bay,to allow for quick "on the road" changing.

Mark
 
Ok, the plot thickens. Had a jaunt out this Saturday afternoon setting off with just over ¼ tank of diesel. Just at the most awkward point where a dual carriageway merges into 1 lane she conks out. I managed to restart her after lots of ticking over, enough to get to the side of the road and out of the way. I left her to cool down for 10 minutes and managed to set off again and pull into a petrol station 400yds up the road. I thought for sh*ts and giggles I’d fill her up to see if that made any difference. She took £75 of fuel which I know is a full tank of diesel. So, my gauge is at least a quarter out. That would explain the stalling effect. I also noticed after filling the tank that plenty of fuel was guzzling out of the tank all over the forecourt! After a minute or two it stopped dripping. I think when it is very full it must be leaking around the filler pipe gasket or something.

So, I set off again once the fuel had stopped leaking (showing over full on the gauge) and low and behold, the car doesn’t miss a beat and again on the return leg she ran beautifully. I also had a similar journey on Sunday morning and she ran fine.

Could it be that all along it’s as simple as running low on fuel? Given all this and I know my tank has crud in it I’m going to order a new one and all the gubbins.

I’ll try and source a new gauge as well (I don’t think it’s the sender as that’s fairly new), or is there a way to test/calibrate the guage?
 
Morning.

Jumping into this thread because I'm experiencing a similar issue with my 1976 Series 3 Diesel.

Over the last year she's had a new lift pump, injector pump, injectors, fuel spill rail, copper pipes (injectors to injector pump), timing chain, water pump etc.

Drove home last night (9.5 miles) in stop/start/heavy traffic. 7 miles in and she started cutting out/stalling. Drove last 2.5 miles with 'throttle' lever open 1/3 to stop her stalling. Drove in this morning (same journey) in lighter/flowing traffic and fine again. The stalling has been a minor problem in the past (actually assumed I'd stalled it) after a really long run (50 miles+) now and then but now a daily thing.

As someone posted above, its a diesel so lack of fuel, air or mechanical failure are about the only things that can stop the engine.

Its obviously an issue that's only occurring when she's properly run up to temperature and the obvious cause would be air in the fuel system but, if that's the case, once its in its in so why would she run perfectly again when starting from cold?

Amount of fuel in the tank makes no difference so not feeling its that.

So why, when running at normal temperature, after about 6/7 miles, why does she cut out unless given/held on the throttle?

This is starting to drive me a bit crazy so all thoughts welcome!

Cheers.
 
Ok, the plot thickens. Had a jaunt out this Saturday afternoon setting off with just over ¼ tank of diesel. Just at the most awkward point where a dual carriageway merges into 1 lane she conks out. I managed to restart her after lots of ticking over, enough to get to the side of the road and out of the way. I left her to cool down for 10 minutes and managed to set off again and pull into a petrol station 400yds up the road. I thought for sh*ts and giggles I’d fill her up to see if that made any difference. She took £75 of fuel which I know is a full tank of diesel. So, my gauge is at least a quarter out. That would explain the stalling effect. I also noticed after filling the tank that plenty of fuel was guzzling out of the tank all over the forecourt! After a minute or two it stopped dripping. I think when it is very full it must be leaking around the filler pipe gasket or something.

So, I set off again once the fuel had stopped leaking (showing over full on the gauge) and low and behold, the car doesn’t miss a beat and again on the return leg she ran beautifully. I also had a similar journey on Sunday morning and she ran fine.

Could it be that all along it’s as simple as running low on fuel? Given all this and I know my tank has crud in it I’m going to order a new one and all the gubbins.

I’ll try and source a new gauge as well (I don’t think it’s the sender as that’s fairly new), or is there a way to test/calibrate the guage?
Series fuel guage sender units are notoriously inaccurate. You need to pull it out of the tank, check to make.sure the float hasnt got any fuel in it and then bend the float arm a little to improve its accuracy. If that dont work, a new sender is needed. I put a new one in my petrol 109 but I ended up worse off. With a full tank, it reads 3/4 and as I use fuel the guage goes up until its about half full then it goes down to 1/4 until it runs empty. I gave up withit and just use the trip to calculate how.much fuel is left.

Col
 
Thanks for the responses so far.

I'm confident its not a fuel level issue, tank sender and gauge pretty good and I always reset the trip anyway as a belt and braces measure. Will double-check though although still wouldn't explain why fine until warmed up and fine again when starting from cold.

Air in fuel?
My first thought but, again, only when hot but fine when cold. Surely air in the fuel lines would result in a constant issue?

Pick up pipe pin hole?
Good thought, will check, maybe opening more as engine heats it up?

Spill return not plumbed into tank?
It's plumbed in but will doluble check connection.

Lift pump diaphragm?
Possible but lift pump less than a year old and a good make, will check.

Thanks guys, keep them coming!
 
Then, when it's hot, check each injector. Safety first, instructions in the manual.
Any smoke when this happens?

I have checked the injectors but will again. There are no apparent fuel leaks anywhere.

No smoke when it happens insofar as I've observed and have ruled out head gasket etc.

The tricky thing is that I either need to put on the miles to get the problem or leave the engine running for an hour or so by which time everything is obviously hotter to touch than one would normally try.
 
If there's no smoke, there's no unburnt fuel....

Get it hot, wear gloves, open the injectors and see if there's fuel going in. Take off the air filter and pipe. See if that makes a difference.
 
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So opened the injectors and there is fuel going in (and yes smoke).

Taking off the air filter and pipe makes no real difference.

I let her run stationary for an hour, idled fine, then 57 minutes in cut out.
 

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