(Home) Pre-heat problem/fuel problem

Hi all. I've just got to say that this site has been a graet help for me over the last couple of months since I bought the Townie(1990 4x4 2.0td). I hav ejust got a real problem starting her in the mornings and after she has been standing for around 5-6 hours. I have replaced the battery for a nice big 90ah, I have replaced the glow plugs for NGK's, but still no joy. There is power right through to the glow plugs(high pre starting & low post). I was wondering if it could possibly be a problem with the fuel gradually draining back after it has been standing a while? I really would welcome any suggestions now as I am starting to pull my hair out now!!!
Many Thanks.
- (#14322) Simon Golding, 29 Nov 04 00:30

Turning over with no smoke could indeed indicate a fuelling problem. Check the fuel filter carefully- is in installed firmly/ sensor attached correctly/ hose clamps tight/ primer pump OK?
Also check the flow and return hoses on top of the injection pump- especially the little one that links the injector return rail to the top of the pump. It hardens dramatically with age...

Remember that the leak you seek is so tiny that it's air, not fuel...

- (#14322) david miller, 29 Nov 04 01:36

thanks for the info david. after lots of tightening of clamps and re-fitting of pipes, i can only now assume that it is the diaphram in the filter housing that is holed/sucking air or it is a case of the pump timing being out. do you tink it is possible to remove the filter & housing and put an in-line filter in place of it?

whatever the problem, it looks as if i will be having another weekend of chasing the problem.

thanks again.......

- (#14322) Simon Golding, 7 Dec 04 13:55

I would endorse your first theory, ie, the possibility of fuel draining back and agree with David's suggestions. You CAN put an inline filter into the fuel line but, you really need the hand priming pump to facilitate the initial fill of the lines. I would suggest, as an experiment, couple up the filter inlet pipe (from the tank) to the filter outlet pipe (to the fuel pump), therebye bypassing the filter & priming pump. This can be done with a small piece of copper or rigid plastic pipe and, in this way, you will be able to indentify any air leak problem with the filter/priming pump assembly. Also, throw away those tired spring clips which hold these pipes onto the filter housing and replace them with new,Jubilee type clips. Air getting in at these joints is fatal to the integrity of the fuel system. The first start might take a while as you will not have the hand pump to prime the pipe and, bleeding each fuel pipe, at it's connection on the injectors, while the engine is turning via the starter, will be neccessary. You can put a piece of clear plastic pipe, at the pump end of the fuel line and assist matters by syphoning some fuel to fill the lines, before quickly replacing the feed pipe. As there is no check valve in the suction tube into the tank, any air leak will allow the fuel to drain back.
The reed type valves, and diaphragm, in the hand priming pump, on top of the filter body, are in a sealed unit and cannot be serviced. These valves can lose their efficiency and then fail to maintain a good "head" of fuel for the injection pump.
When this happened to me, the fault did lie in the priming pump valves and the only answer was to replace the assembly. I got my unit from a breakers and it cost only a few pounds.

- (#14322) John Davis (Leics), 7 Dec 04 14:39

Yes, I've had trouble from air leaking into the fuel line. I think that new nut-and-bolt type clips are even better than Jubilee type. When you bypass the filter make sure you make the joints tight.

I've done a lot of swapping of inline filters and found the system ahead of the injector pump needed no special priming - would sort itself out.

Another thing you might check is whether a leak has developed around the "throttle" input shaft on top of the fuel pump. This will leak fuel out slowly when the engine is running but let air back in when you're parked. Air there is more troublesome. In cold weather you might not notice the fuel leak.

- (#14322) Dave Mason (Sussex), 8 Dec 04 03:56

Thanks for all the advice, I will strip it at the weekend & let you know how I get on.

- (#14322) Simon Golding, 8 Dec 04 14:08

Hi All,
Well at last I have had the time to really go through everything that has been suggested, but still no joy with the cold start. I have had the injector timing set, and the fuel delivery etc. The main fuel filter was by-passed with an inline filter etc, etc.....
The ace really goes well now with no hessitation at junctions, just real pulling power(for an ace anyway!).
I just will not start from cold without a lot of cranking, it will fire up after around 15-20 turns but will not keep going even if you try a little throttle. You are then back to square 1, and away you go again with the cranking and getting no-where. Eventually it will fire again & by keeping the key turned till the last second it will pick up & run.
If anyone has any ideas at all, please share them as I have very little hair left on my head now!!!!!
Here's Hoping!!!!

- (#14322) Simon Golding, 23 Jan 05 05:21

Still reckon on an air leak. Have you checked all the hose connections the whole way back to the tank? What about the injection pump itself- any sign at all of fuel leaking when the engine is running? If there is, you could have the return line syphoning the pump dry.

You *might* try pressurising the system (via the breather hose on the tank)to maybe 10psi to see if you can make any of the leaks more visible. Be careful if you're attempting this tho...

- (#14322) David Miller, 23 Jan 05 06:45