Topic: Ok, I'm stumped. Ideas?... (Read 13052 times)

bigfatsi · « **on:** July 12, 2011, 11:19:10 »

Hi everyone, it's great to see you all back!

Now, a question...

Recently I put my 90 (200tdi) back on the road after a couple of months on the drive. Everything was fine for a bit, but now it's not!

I suppose I'd better start with what I did, that could have created the problem. It'll be my fault somewhere...

Firstly, I put in too much vegetable oil. I've ran it on SVO dozens of times, but put too much in at home before topping up with diesel to thin it out a bit. Result was a knackered lift pump (duly replaced).

This seemed to sort things out for a bit and I was away. Next I changed the fuel settings back to nearly normal (200tdi tweak) settings to increase mpg at a loss of power. Again, things were fine but a bit sllllooooowww. Then it developed a bit of a rough/misfire patch. I replaced the fuel filter and reset the fuelling at mid-level which seemed to cure it.

Now, however, it has started to run like a pig. Symptoms are 1. Lack of power. Total. 30mph max. 2. Misfire only at high revs. If I floor it, it'll go the redline and start coughing and blowing white smoke. 3. When you come off the throttle it acts as though it has been starved of fuel and coughs a bit as if the filter is filling up again.

It was suggested that I'd likely fouled up an injector, but I've changed them for a spare set with the exact same results. :(

So could we have a differential diagnosis? I'll put my thinking on the table:

1. Wrong fuel lift pump. Definitely looks different, however it seems to be working
2. Leak in fuel lines somewhere (although I don't know where - I've tightened and checked as best I can)
3. Knackered Injector pump

4. Unseated fuel filter allowing air in
5. Head gasket

Any other suggestions or comments? Please?!

TIA

Simon

V8burble · « **Reply #1 on:** July 12, 2011, 11:57:41 »

head gasket

barmiebrumie · « **Reply #2 on:** July 12, 2011, 13:39:22 »

sedimentor thingy ?, I had the same on the disco I just bought as previous owner had tried to run it on neet veg via a heater, took all that out & then checked the sedimenter (under o/s/r arch on disco) by passed it by cutting the feul line & putting a new piece in, also changed fuel filter & blew the fuel lines through with high pressure air line. cured it straight away

Hope this helps

John

bigfatsi · « **Reply #3 on:** July 12, 2011, 14:23:01 »

Thanks V8 and Barmie.

Mine doesn't have a sedimenter but I guess it could be an air leak in the system somewhere.

Head gasket seems likely, however I should add that after running with my foot down for a bit, it seems to struggle to idle as if it was starved of fuel. I had similiar symptoms when the fuel lift pump went - the tickover would be low after acceleration and gradually pick up as the fuel returned - almost as if the fuel filter had been emptied and was refilling. Could this be as simple as an air leak on the fuel filter or a pump with low flow?

Simon

bigfatsi · « **Reply #4 on:** July 13, 2011, 10:44:33 »

Latest update:

Last night I changed the fuel filter and it has made a marked improvement. Power is up but there is still a misfire right at the top of the rev range - Full boost. Surely, if it were the head, there'd be problems at all revs including tickover? Smoke is only when the engine is misfiring and the engine surges as if it were low on fuel and ends up kangarooing.

I'll check the little turbo pipe across from the turbo tonight in case that has a hole in. Any other suggestions?

S

Axetamer · « **Reply #5 on:** July 15, 2011, 20:31:40 »

mine had a filter on the bottom of the fuel pickup pipe actually inside the tank...don't know if this was an original feature or a mod by the previous owner...looked like a metal teabag affair... this kept filling up with sediment in the tank causing fueling problems, I have cut this teabag thing off and have put in a prefilter before the pump.. just one of those clear cheap inline things. ...a simple cut and insert with a couple of clips...added bonus is you can see the fuel coming through when the engines running helping with diagnosis..

Saffy · « **Reply #6 on:** July 15, 2011, 22:18:48 »

Quote from: Axetamer on July 15, 2011, 20:31:40

mine had a filter on the bottom of the fuel pickup pipe actually inside the tank...don't know if this was an original feature or a mod by the previous owner...looked like a metal teabag affair... this kept filling up with sediment in the tank causing fueling problems, I have cut this teabag thing off and have put in a prefilter before the pump.. just one of those clear cheap inline things. ...a simple cut and insert with a couple of clips...added bonus is you can see the fuel coming through when the engines running helping with diagnosis..

was it a petrol truck once or did tank come off one? petrol90' ones I seen have had mesh filter in tank and caused no end of trouble when tank was fitted to my diesel. Diesel from the pump is full of a crazy amount debris like fibre glass! and those mesh filters clog up in a few miles.

Range Rover Blues · « **Reply #7 on:** July 20, 2011, 22:29:32 »

Faulty lift pump? wouldn't be the first time.

bigfatsi · « **Reply #8 on:** July 25, 2011, 11:08:10 »

Latest update:

I have replaced the fuel lift pump again and replaced the old TD fuel filter assembly and pipework with the proper 200tdi jobbies. All new pipes and connections. The tank is pristine. Spotless. So is the diesel.

Fault is still there occasionally although I can now do 60mph (up from 50 which was up from 30!)

Hard plastic pipe from turbo to injector pump is fine and not leaking. Turbo is spinning up and everything runs sweet as a nut for the main part. However it is still not right

Any ideas? Are there any filters inside the injection pump that could have debris from the blown lift pump stuck in them?

S

Saffy · « **Reply #9 on:** July 25, 2011, 11:20:58 »

have you done the value timing (tappets)

bigfatsi · « **Reply #10 on:** July 25, 2011, 13:19:40 »

I did them not too long ago Saffy. Suppose it wouldn't harm to check 'em again! Ta.

S

Saffy · « **Reply #11 on:** July 25, 2011, 15:37:43 »

could check pump timing too, maybe belt jumped a tooth or was never aligned on markings properly when fitted.

TDi90 · « **Reply #12 on:** July 26, 2011, 20:07:31 »

Yes, i would go for the cambelt next. take it off and replace (as your there.) Time her up.

90Mike · « **Reply #13 on:** July 31, 2011, 18:23:42 »

Had the same thing on a disco recently, when we took the fuel pick up out of the tank and checked the end it looked like it was blocked with jelly, quick blow out with the air line now runs perfectly. If you dont have any luck there next step would be cambelt / pump timing

bigfatsi · « **Reply #14 on:** August 09, 2011, 10:08:12 »

Thanks for all the input.

Latest update:

For some reason the truck decided to fix itself for a week and ran spotlessly. No problems whatsoever. Then, out of the blue, the problems came back. But worse.

Struggled to get it home after a quick run down the road. No power at all. Engine would die as if starved of fuel then come to life for a few seconds, then die, then come back to life. Finally it would stall but start again straight away.

Starts no problem on a morning so I'm confident it isn't an air leak in the pipe. Took the inspection panel off the cambelt casing and grabbed the IP 'nut'. Had quite a bit of end float play (about 1-2mm) so I'm presuming it's goosed.

I've bought a 300tdi FIP to replace it and I'll do the cam belt at the same time. Wish me luck. If it isn't the IP then I'm gonna scream!

Thanks again. I'll keep you updated.

Simon

L90OOK · « **Reply #15 on:** August 09, 2011, 21:38:02 »

Your lift pump may have a fine filter that blocks easy.
The veg oil cleans all the rubbish out the tanks & fuel lines.
Try cleaning lift pump. If that works I'd fit an inline filer between tank & lift pump.
Ask me how I know

bigfatsi · « **Reply #16 on:** August 10, 2011, 12:06:13 »

Thanks for replying L90OOK,

I've replaced the fuel lift pump (twice!) the lines and the filter housing and filter (twice!). The tank is pristeen so there is no crud anywhere, except possibly the FIP.

Nightmare, huh?

S

L90OOK · « **Reply #17 on:** August 18, 2011, 19:01:18 »

I assume you have had the fuel pick up out & checked for blockages?
What about the unions on filter housing & FIP?

Axetamer · « **Reply #18 on:** August 18, 2011, 20:49:05 »

Quote

Quote from: Axetamer on July 15, 2011, 20:31:40
mine had a filter on the bottom of the fuel pickup pipe actually inside the tank...don't know if this was an original feature or a mod by the previous owner...looked like a metal teabag affair... this kept filling up with sediment in the tank causing fueling problems, I have cut this teabag thing off and have put in a prefilter before the pump.. just one of those clear cheap inline things. ...a simple cut and insert with a couple of clips...added bonus is you can see the fuel coming through when the engines running helping with diagnosis..

was it a petrol truck once or did tank come off one? petrol90' ones I seen have had mesh filter in tank and caused no end of trouble when tank was fitted to my diesel. Diesel from the pump is full of a crazy amount debris like fibre glass! and those mesh filters clog up in a few miles.

Mine was doing exactly what yours is still doing....mine was originally a petrol..now a 200tdi, and would lose power then after the engine was stopped for a while and then restarted run perfectly for about 20miles or so...then gradually lose power..on mine it was this teabag mesh thing causing the problem, once removed problem cured.

To me it seems as if you've a blockage somewhere...could be a leaf or flake of paint, rust or anything like that being picked up, blocking the pipes then falling back into the tank when the motor is switched off?....do you do a lot of offroading?

jimyd · « **Reply #19 on:** August 20, 2011, 07:06:00 »

Still sounds like fuel stavation to me. I have fitted a tempory bit of clear pipe in the fuel line just before the injector pump before, that way you can see if its sucking air in. I have also run tempory fuel lines from a 5l fuel can strapped to the roof to give a 'positive gravity feed' to help identify fuel starvation issues.

kizz81 · « **Reply #20 on:** August 20, 2011, 16:11:49 »

We had this on our 200 Disco, same symtoms after veg oil, swapped all the fuel pipes and that cured it ( its cheap to do ), Veg oil cleans all the crap through your system,
had a similar thing on my 90 when driving down to stoneligh last week for all those who saw me with my bonnet up by the side of the M1, i was tightening up the fuel filter which cured it,
sounds like air in the system, or crap lodged in some where try some wurth diesel treatment (only brand ive found which made a notable difference)
failing that white smoke indicates head gasket,
another thing that made one of our 200's slow was a seized turbo regulator, easy to cure using adjustable spanner and some lube, gentally ease back and forth
failing that check your breathers

failing all of that go to the pub

bigfatsi · « **Reply #21 on:** August 30, 2011, 09:19:59 »

It's fixed.

Saturday morning, armed with a box of copper washers and a roll of fuel pipe I systematically began changing all the fuel lines. As it turned out the last one (the one from the tank to the lift pump) was the culprit. Presumably it was within the union on the tank as the lift pump end has been on and off numerous times.

Anyway, its now got a new cambelt, tensioners, lift pump, fuel lines and a replaced 300tdi FIP and I can move onto the vague steering and P-poor braking performance. Ho hum...

Cheers everyone!

Simon.

Saffy · « **Reply #22 on:** August 30, 2011, 12:16:43 »

letting in air or crush restriction ?

bigfatsi · « **Reply #23 on:** August 30, 2011, 16:27:53 »

Who knows?! Can't find anything wrong with the original pipe, but replacing it has fixed so it must be the pipe. QED

Simon

Saffy · « **Reply #24 on:** August 30, 2011, 17:06:55 »

I had a few teething problems with a twin tank svo setup with heat exchanger. After x number of miles the heat of the fuel would soften the fuel pipes and the type of joint unions used would then crush the soft pipes closed.

I also had problems when running purely on diesel in both tanks on long trips, after xxx miles and hours of driving the flat plate water heated heat exchanger that was still inline would have heated the diesel up quite hot, including what was circulating back to the tank. The engine would lose power. I can now switch the HE in and out of the circuit, or rather turn off it's hot water supply.

bigfatsi · « **Reply #25 on:** September 06, 2011, 10:50:52 »

And....guess what?

The problem is back

Now to change all the unions. Fun huh?

Simon

SI COOPER · « **Reply #26 on:** September 16, 2011, 20:45:25 »

did you change the copper washers when you changed the injectors sounds like air is getting in to me

bigfatsi · « **Reply #27 on:** September 17, 2011, 09:11:16 »

After the problems came back I replaced the unions on the tank and the lift pump. That seemed to fix it. It's been running ok for a week or so now. Fingers crossed!

S

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AuthorTopic: Ok, I'm stumped. Ideas?... (Read 13052 times)