GU TD42 MISSING

[RUSSMUSS]

hey everyone,
i have a gu ute 4.2 turbo its missing on cold start up but only at around 1500 to 1800rpm then goes away after a couple of minutes???. its fine at idle

secondly if you sit at a set of lights for a few minutes then take off and rev it 1st & 2nd it starts to hesitate around 2000rpm but will only do it in 2nd gear no other time???

i have checked all the fuel lines for leaks or cracks, cleaned out fuel lines from pick up to the filter & down to the pump, put in new fuel filter & checked the little guaze in the pump but it wasnt there.

any help would be great
thanks russll

[toughnut]

Check the thimble filter that is in the injector pump. This is a common problem especially if you have just changed your fuel filter. (Not sure why).
Trace your fuel line from your filter to the injector pump and then disconnect it from the pump. Inside the opening is a small thimble shaped brass filter. Its easy to get out with a bent up paper clip. Give it a clean then refit your fuel line and you should be sweet. If that isn't the problem then I'd be looking at your main fuel filter.

[RUSSMUSS]

i couldnt find the little filter i tried to see it but with no luck, might change the main one again
but i have a feeling it might be a bigger problem then just filters

[toughnut]

It is very hard to see. Get a plastic stick or something like a lollypop stick/straw and gently push it in to the hole to see if its in there. A paper clip like a small hook is all you need to get it out. Some people remove these filters because it can be a pain in the butt sometimes but if it is getting clogged then there are other problems that you'll just mask. Here are a few things that it may be:

1. Thimble filter
2. Main fuel filter
3. Fuel line not bled properly or air getting in the fuel line somewhere
4. Crappy or blocked injector
5. Injector pump timing

It sounds like a fuel problem to me rather than something else.

[GU-ish]

mine does this too, on start up only sometimes and mine does it in 3rd gear at about 2800 rpm

[toughnut]

I saw elsewhere that you got it sorted out russmuss. Good stuff.

[RUSSMUSS]

no i havent got it sorted yet its still doing it, ill check for the guaze again & change the main filter, ill see how it goes might get the injectors done

[toughnut]

So it wasn't you on mudrhino? That post was nearly identical and he blew compressed air through his fuel lines to his tanks and it worked fine after that.

http://forum.mudrhino.com.au/viewtopic.php?t=10752

[dibbo]

i would fit a clear hose between the fuel primer pump and the injector pump and see if you are sucking any air through i have seen this before they can suck air through the primer.

[some_guy]

So it wasn't you on mudrhino? That post was nearly identical and he blew compressed air through his fuel lines to his tanks and it worked fine after that.

http://forum.mudrhino.com.au/viewtopic.php?t=10752

that was me, was just a blocked fuel line

GU-ish mine did the same thing, blew the fuel lines out with compressed air and bleed the system an its fine now

[RUSSMUSS]

how do you s bleed you system maybe in not doing it right??

i ll try reblowing it alll out & put the clear hose on as see what happens

ill keep you posted thanks

[toughnut]

To bleed it properly I crack the banjo bolt where the fuel line goes into the injector pump and then pump away until you don't get any air anymore. Then I crack the number 6 injector and pump away till there is no more air. If you want to go crazy then you can crack each injector and repeat.

[some_guy]

the way i do it (the way recommended by the workshop manual i have)

there is a screw on the top of the injector pump, loosen that off a little. pump the primer on the fuel filter till clean (no air) comes out
tighten the screw up
loosen the bleed screw on the fuel filter, repeat as per injector pump
tighten that screw up, then pump away till the primer goes hard

seems to work for me

[toughnut]

the way i do it (the way recommended by the workshop manual i have)

there is a screw on the top of the injector pump, loosen that off a little. pump the primer on the fuel filter till clean (no air) comes out
tighten the screw up
loosen the bleed screw on the fuel filter, repeat as per injector pump
tighten that screw up, then pump away till the primer goes hard

seems to work for me

Wouldn't you do the filter first? Seems the wrong way around to me. I would have thought that you'd get the air out of the filter first so you don't push it further down the line.

[lux44]

mine did it last year when i had to do a cold morn start... when the weather warmed up it was fine, started doing it again in the cold mornings, new glowies and its like new again! ahhhh maintenance. you can also just glow it a few times or wait till you hear the relay click rather than watch for glow light to go out, this helps heaps. and let it warm up a bit in the morning
hope this helps

[claydos]

Hey,

just my 2 cents, I have a 99 GU that does the same thing, initially I thought it was glow plugs, has been doing it for years now, (yes I am lazy as sin) and now I seem to be blowing/weaping a little bit of oil out of the oil cap. It has been suggested that I may have a cracked head, so that may be somthing that may be causing it. Let us know what fixes it as I may not have to whip the head off yet

Clay

[oldmate]

It doesn't sound like blocked filters or lines. That would normally cause missing at any rev, often really high revs. Could be injectors, pump or a head valve problem. There's no way of checking these things so it's just a matter of having each item tested. It means big dollars, but that's always been the case with diesel engines.

Start with the injectors if they haven't been done recently, or at all. THat is the cheapest thing to do. But I think it sounds more like a head problem.

[some_guy]

the way i do it (the way recommended by the workshop manual i have)

there is a screw on the top of the injector pump, loosen that off a little. pump the primer on the fuel filter till clean (no air) comes out
tighten the screw up
loosen the bleed screw on the fuel filter, repeat as per injector pump
tighten that screw up, then pump away till the primer goes hard

seems to work for me

Wouldn't you do the filter first? Seems the wrong way around to me. I would have thought that you'd get the air out of the filter first so you don't push it further down the line.

that makes sense, i haven't had a problem yet

but thinking about it, most of the time i don't bother with the injector pump, just bleed it at the filter
only time i do the injector pump is if i touch the fuel lines between the filter and pump

[RUSSMUSS]

i doubt it s head valve problem, it never blows smoke besides on cold start when it misses which is unburnt diesel, it doesnt use oil or coolant and not one little oil leak anywhere

ill check the glow plugs this w/e

i put some injector clean threw it & it has almost stopped the problem

keep up the good work so far guys & ill keep you posted