Loss of power

[Lorin]

Since Lincomb I have a noticable loss of power - probably by about 30% There are no other symptoms - it is not smoking, the turbo whistles and kicks in how it always did, the oil level is fine, there are no fuel leaks and no noises or warning lights, it simply has no power. On one hill that it normally easily holds 60mph up in 5th I ended up having to use third with my foot floored just to get up

It was serviced (i.e. all filters and oil changed) just before Lincomb and was running absolutely fine before and after the service. The fuel level never dropped below half at Lincomb but obviously the truck did get bounced around a lot I first noticed the power loss driving round the woods in low range and thought it would just clear itself, but it hasn't.

One thing I've noticed is that if I feather the throttle it drives pretty normally. If I then give it any throttle it seems to hesitate as if it is not getting enough fuel. If I give it 100% throttle it very slowly picks up but again feels as if it isn't getting enough fuel.

Hoping it is something relatively minor I'm thinking it might be a fuel blockage somewhere. Other than changing the fuel filter what else could I change / where else should I look? Is there any point running a load of fuel cleaner through? Any advice would be greatly appreciated.

 

[fridayman]

Sounds like a fuel blockage somewhere.

 

[Scott]

Hi Lorin, sorry to hear of your troubles. I recently had the same problem with a Vauxhall Vectra. I traced the fault to a failed turbo waste gate actuator pipe, it maybe a red herring, but it might be worth having a check of the turbo waste gate actuator operation as well.

Good luck.

 

[Lorin]

Cheers Scott, I'll check it out

 

[Toby]

Lorin,

If changing the fuel filter doesn't help matters it could be worth checking the pick-up screen in the fuel tank. The rear seat needs to come out, then remove or make a suitable incision in the carpet and remove the cover plate above the fuel tank. You'll then be able to pull out and clean the pick-up. Try not to get diesel on your carpet though...

It could also be worth checking the fuel supply line and particularly the filter for air leaks whilst you're at it. Does it idle smoothly?

Best of luck,
Toby
1990 HDJ80
1994 HDJ80

 

[Scott]

If changing the fuel filter doesn't help matters it could be worth checking the pick-up screen in the fuel tank.

Well remembered Toby.

An 80 that was travelling with me in the Pyrenees this summer, started to drive strangely after it went off-road for the first time, it was fine off road but as soon as you asked any power of it once back on tarmac it didn't deliver. Instead it was sluggish and didn't seem to change gear correctly (auto). After a while on the road it would improve and drive ok again.

We monitored it again the next day, and it did the same thing again, but worse. The driver was concerned it was the gearbox at fault, but with a few questions I found out that it had been standing for quite a while, this coupled with my thoughts that it was more likely fuel starvation, led to me spending a hot Spanish summers evening stripping out the diesel pick up.

It was absolutely caked solid, it was amazing that it had any power at all! After a good clean it was all reassembled and all fingers were crossed.

The next day it went like a train all day, including after we'd finished driving the tracks. The owner was very pleased that it was something so simple.

 

[Beau]

I have pretty much the same problem on my colorado the other day.

I changed the fuel filter and cleaned the filter in the tank and didnt change anything....I think I have a blockage somewhere near the injectors so im going to try some injector cleaning stuff and see if it helps!

 

[Chris]

Don't be tempted to take a short cut and use compressed air to blow down then fuel pipe. It will blow the filter off the end!

Chris

 

[sae70]

I wonder if it's worth checking the air filter before getting to involved, as it looked pretty dusty at Lincomb in the photos

 

[paulm]

had the same problem with a ford ka (no chuckling at the back) and it turned out to be the backbox failed. might be worth a shake to see if its rattling

 

[Lorin]

I wonder if it's worth checking the air filter before getting to involved, as it looked pretty dusty at Lincomb in the photos

Checked the air-filter - was all okay there

had the same problem with a ford ka (no chuckling at the back) and it turned out to be the backbox failed. might be worth a shake to see if its rattling

Exhaust is stainless straight-through so shouldn't be that. I did check in case it had got badly dented but again is all okay there.

If changing the fuel filter doesn't help matters it could be worth checking the pick-up screen in the fuel tank. The rear seat needs to come out, then remove or make a suitable incision in the carpet and remove the cover plate above the fuel tank. You'll then be able to pull out and clean the pick-up. Try not to get diesel on your carpet though...

It could also be worth checking the fuel supply line and particularly the filter for air leaks whilst you're at it. Does it idle smoothly?

I did wonder about an air leak However, the truck idles perfectly and drives fine on a feather throttle. I'll swap the fuel filters and then go for the hole in the carpet and clean the pick-up screen and see what happens

 

[adrianr]

I'll swap the fuel filters and then go for the hole in the carpet and ...

don't think you need to cut a hole - remove rear seats and the carpet should unclip and pull forwards out of the way.

good luck.

 

[Lorin]

I have a new symptom and I don't think it is good

I haven't done anything to it yet as that was a job for Saturday, so it has sat unused since returning from Lincomb. I went to start it this morning and it wouldn't start. I gave it enough throttle to start and it is belching fairly substantial amounts of thick smoke In terms of colour the smoke appears to be white-ish but I guess it could have a blue tinge - is hard to tell. The smoke is definitely not the black you get with unburnt fuel. It clears with a good rev but then reappears on over-run (i.e. a lot of smoke). If I try and rev the engine it is hesitant and lumpy until approx 2000rpm and then it revs freely. It continues to smoke visibly on tick-over. I have checked the coolant level and it is fine. Unfortunately I cannot check the oil without driving somewhere flat as I park on a slight incline and I'm not sure I want to risk driving it.

Am I right in thinking this looks like a turbo issue?

 

[Scott]

don't think you need to cut a hole - remove rear seats and the carpet should unclip and pull forwards out of the way.

I've done this job on two 80's and I haven't had to cut the carpet on either, unbolt and remove the rear seats, then remove the plastic foot plate just inside each of the rear doors, you should then be able to tease the carpet off of the locating posts at the front edge of the load bay and roll the carpet to the front of the vehicle. This will reveal the inspection plate that you need to remove.

Give the top of the tank a good clean, or a blast of air, to get rid of any debris that might fall into the tank whilst you remove the pick up. Also, shine a torch into the tank to see if there is any debris inside.

The only reason you'd need to cut through the carpet is if you have an built in storage system, or false floor, that has trapped the carpet or covered the area in question, that'll make it more intersting.

Enjoy.

 

[Paul]

Oil level is a good place to start to rule out a faulty injector or pump seal.

 

[Scott]

I went to start it this morning and it wouldn't start.

Interesting. A diesel engine just needs fuel and air in manageable quantities, at the right time to start. You say that yours is parked on a slight incline, is it nose up or down?

Could it be that you have an air leak in the fuel system that has allowed all the remaining fuel in the filter and lines, to drain back to the tank? This would mean that when you tried to start it there was no fuel and it would have had to crank for a while to draw the fuel back up.

Air can be drawn into the diesel system at any point, but don't expect to see diesel leaking out, air can get though some very small gaps where diesel can't.

Have a real good look at the whole fuel system, try to feel all the pipes and joints for any evidence of chaffing against anything whilst you've been offroading. Also give the intake system a good going over, particularly the turbo pipes, take them off and check that they are in good condition and not delaminating internally and restricting the air flow.

Good luck.

 

[Chris]

I had that with mine. It's the diaphragm in the primer pump that goes into pin holes and allows the fuel to siphon back to the tank. I fitted a Bon return valve plus filter and it cured it. Can't say that IS your problem but if there is no fuel in the pipe it's a fair bet that this is it.

Chris

 

[Paul]

Is that supplied from France?

 

[pugwash]

I have a new symptom and I don't think it is good

I haven't done anything to it yet as that was a job for Saturday, so it has sat unused since returning from Lincomb. I went to start it this morning and it wouldn't start. I gave it enough throttle to start and it is belching fairly substantial amounts of thick smoke In terms of colour the smoke appears to be white-ish but I guess it could have a blue tinge - is hard to tell. The smoke is definitely not the black you get with unburnt fuel. It clears with a good rev but then reappears on over-run (i.e. a lot of smoke). If I try and rev the engine it is hesitant and lumpy until approx 2000rpm and then it revs freely. It continues to smoke visibly on tick-over. I have checked the coolant level and it is fine. Unfortunately I cannot check the oil without driving somewhere flat as I park on a slight incline and I'm not sure I want to risk driving it.

Am I right in thinking this looks like a turbo issue?

what you could do is to isolate the coolling jacket from the turbo- two small pipes that drop down from the head to the turbno housing- basically they pass water around the turbo.

FWIW, my turbo seals have been leaking for ages- as a "temporary" fix i disconected the water pipes.

45k miles later, 2.5 years, and 4 long range trips abroad the turbo hasn't got any worse, and its stopped smokig and being all asthmatic.

do make sure on regular fully synth oil changes, and turbo cool down time after a long warm run though!

 

[Toby]

Hi Lorin,

Could be a turbo or injector issue, but still sounds more like fuel problem, quite possibly an air leak, to me. If the fuel filter was recenly replaced (you mentioned a recent service) maybe a seal wasn't seated quite right and has been sucked in a bit causing an air leak? This could account for the fuel draining back to the tank and hence difficult starting...

You won't usually get black smoke until the engine is hot and there's over-fuelling.

Internet diagnosis is bit hit and miss at the best of times though.

Best of luck,
Toby
1990 HDJ80
1994 HDJ80