Rough Running LJ70

[StarCruiser]

Exactly that. Just disconnect the fuel line going into the filter and attach a piece of hose, clear will show fuel being drawn up when you operate the primer. Once primed you shouldn’t see the fuel get bubbles in or the level drop back. Sometimes fuel primer pump diaphragms get perforated and allow air in but your symptoms don’t sound like that.

Not being familiar with your truck, I’m curios to know what you mean by ‘the bladder’?

 

[outdoordan]

yup. just pipe into a plastic pop bottle

 

[AlexDukes]

Thanks everyone for your help so far

So, i put 1 litre of injector cleaner through the truck, it ran really rough during the process big plumes of black smoke, had to rev it a little to keep the engine running, whilst revving it, it even backfired quite a few times.

I then put 5 litres of diesel through the car, it did seem to idle better so i took it for a test drive.

It then behaved roughly the same way as before although very marginally better, but still wanted to stall when coming to a stop and still no performance.

I am very worried about the turbo lights aswell as i said previously, red light congress on at 2500 revs when accelerating hard???

What's next guys??

 

[outdoordan]

Did you drive it running fuel from a bottle? I'm not sure what the issue with the turbo is not knowing the engine well.

The symptoms you describe are likely fuel related.

Starvation and/or contamination.

Eliminate possible causes systematically.

Start with the easiest/most obvious.

If you haven't already change air filter and fuel filter.

Clean sedimenter if there is one.

Check all hoses thoroughly.

Run off a temporary fuel supply. Cable tie a bottle of fuel somewhere close to fuel filter as per star cruisers instructions.

Setting tappet clearances might help.

 

[AlexDukes]

Thanks Outdoordan,

So, I tried running the truck from a bottle, it got through 5 ltrs damn quick!

The running seemed to be much smoother and no stalling, there also seemed to be a slight increase in performance!

So I am guessing there is another problem somewhere down the fuel system? This time round, I was naughty and bypassed the fuel filter and went straight into the bladder.

I have ordered a new fuel filter, but I am a little worried after my first issues with a blocked return pipe that it is going to be one of the pipes? Is it best to just run new fuel lines from front to back? To save the messing around or does the fuel tank usually cause issues?

Thanks everyone for all your help so far!

 

[StarCruiser]

Whatever you do Alex you need to find what the problem is before just replacing whatever you guess the problem is for that way lies financial pain and frustration.

Do not bypass the fuel filter again without adding some sort of in line filter or you risk wrecking the injection pump by the tiniest particle of dirt entering. The clearances in any hydraulic system, especially a diesel injection system, are only microns and a single particle of dirt can cause scoring and leakage.

Your improvement shows that you have some sort of problem with either filter, primer, fuel pipes, fuel filter sock, fuel pick up pipes, breather or fuel.

Pipes can be blown through with air and plugged one end and plugged one end and lightly pressurised to detect leakage. The diaphragm in the primer pump can be checked by putting a finger over the intake or outlet and pumping the primer. If on the inlet, the primer should stay down until the finger is removed. On the outlet you should feel pressure and resistance to pressing.

WHAT DO YOU MEAN BY ‘THE BLADDER’ please post up a photo.

The breather can be checked by running with the fuel cap slightly open on a low tank of fuel.

Only use Toyota fuel and engine oil filters. There’s not much difference in cost and they are the best.

After this it’s drop the tank. Empty out fuel and check for slime and water. Remove the sender/pickup plate and check pipes for holes and the filter sock for blockage. Check inside the tank for slime (diesel bug) and water damage (rust).

Check any flexi hoses for internal crushing. They can delaminate and suck in. Refit each part checking as you go and ensure no leaks.

 

[alexy]

I run a piece of transparent hose at the exit of the fuel filter towards the injection pump so I could see if theres air in the fuel line.

old filter was letting in a lot of air, bought a new filter housing from roughtrax hoping that would solve it.

brand new filter housing with brand new toyota filter installed still lets air in, but much less then original filter housing.

 

[outdoordan]

Check all the flesh hoses in the rear wheel arch. I reckon you've got a perished or split hose somewhere up there. There might be a little inline filter up there as well. Replace it if there is.

 

[Ash Awbery]

Hi, sounds like you have the same issue I have had with my LJ70 and LJ78 the steel pipes can be corroded at the fuel tank end, and drawing in air.
Only way to really know is by dropping the fuel tank down.
In the end I made a new fuel tank for the LJ70 and repaired the fuel pickup pipes in the LJ78 (one day I will just buy new pipes)


Ash

 

[AlexDukes]

So, a little update!

I had quite a few jobs to do over the car, so I have changed the following.

The radiator
Fuel Filter
Air Filter

I then decided to drop the fuel tank and found a horror story inside! rusted to buggery and the fuel uptake filter inside the tank beyond repair!

Several baths of acid later, and a few jet washes, the inside of the tank is pretty respectable again, so a couple of new questions....

Firstly.. Can I just put a small filter on the end of the fuel uptake pipe inside the tank, or does it have to be the original toyota part (bearing in mind, I am in France and everything even if it is in stock takes 5 weeks to get here!). Or even run no filter in the tank at all?

Secondly.. What are all the pipes for out of the tank? Are they really necessary? Can they be blanked off? I have the fuel filler pipe, fuel filler breather, fuel in and out from the uptake to engine... what are the other 3 pipes????

Thanks guys

 

[outdoordan]

not sure about the three pipes.

if you put your chassis number into partsouq website it should come up with explded diagrams and part numbers for your truck. that should help explain.

also not sure about the filter in the tank. again check partsouq for part number and try to order online. call nick ould at euro 4x4... he might be able to help. he's a wizard for parts.

you can fit any number of inline filters between tank and main fuel filter under hood.