The one i drove would not rev above 1400 revs the tacho /speedo needle would not always work and the tacho trace was very prominent
ianto:
The one i drove would not rev above 1400 revs the tacho /speedo needle would not always work and the tacho trace was very prominent
OK, speedo and tacho?rpm counter always work fine, like i say rev counter is slow to respond.
A few times the cruise control has stopped working after stopping… but that may be unrelated…
After the repair, the truck you drove would rev ok, up to 2150?
after repair everything worked perfect i was told that VOLVO did have a bad batch of senders and if found that you had a faulty sender they would replace them i was also told that on the tacho that there could be a problem with the wireing in the loom and that there was a replacement loom to be had
it sounds more to me like a boost pressure sensor problem or similar, it doesnt sound mechanical… but does sound like its in a tourqe limiting mode. if you can get it do a dealership then id recomend it as there computers are so much better than most other workshop hand held computers, i cant remember now but if you can watch ur turbo pressure on ur dash see what its boosting at on the flat & on a pull.
just had a thought it my sound daft but as your truck is from a large fleet some things can be set/limited… if you go into the menu on the dash readout you can set various fleet limits including rev limits, engine idle time, speed etc you will need the password
only other thing is the throttle pedal sender but these more often than not just get worse, one thing to check is the drivers side top corner of the windscreen rubber, as when not fitted right water can enter, run down the door pillar and drip directly onto the throttle pedal sender!
how’s the oil pressure and engine temp?
if you have been parked up for a while and then pull out back onto the road and back up to speed without touching the brakes the cruise control wont work straight away, dab the brakes 2/3 times and then switch it on, it’s some sort of daft safety idea!
truckers boy:
it sounds more to me like a boost pressure sensor problem or similar, it doesnt sound mechanical… but does sound like its in a tourqe limiting mode. if you can get it do a dealership then id recomend it as there computers are so much better than most other workshop hand held computers, i cant remember now but if you can watch ur turbo pressure on ur dash see what its boosting at on the flat & on a pull.
I will get it back to another dealer and get it on their computer, dont trust the last place…
Turbo boost low on the flat, rises to the end of the gauge on a hill, until you get to the end of the green, then it drops off…
Moose:
just had a thought it my sound daft but as your truck is from a large fleet some things can be set/limited… if you go into the menu on the dash readout you can set various fleet limits including rev limits, engine idle time, speed etc you will need the password
only other thing is the throttle pedal sender but these more often than not just get worse, one thing to check is the drivers side top corner of the windscreen rubber, as when not fitted right water can enter, run down the door pillar and drip directly onto the throttle pedal sender!
how’s the oil pressure and engine temp?
if you have been parked up for a while and then pull out back onto the road and back up to speed without touching the brakes the cruise control wont work straight away, dab the brakes 2/3 times and then switch it on, it’s some sort of daft safety idea!
I have the code for the fleet limits and can adjust all the bits, speed limiter, RPM limit etc… Makes no difference to the sort of eco mode it seems to be in…
Throttle seems to be even, but i will look into that for sure!
Oil pressure and engine temp are good, in the on screen menu, the oil tenp sits around 80 unless working hard up a hill, it can climb to around 105… I feel this is a bit high for mineral oil…
That explains the cruise control issue! Thanks very much for that! Ha ha ha! simple to fix!
what sort of weight are you pulling? the temp seems about right to me, as for the rev counter they can give problems as the dash clusters are not the best, there is a firm not far away from me that repair them (the pointers on the gauges can have a mind of their own)
there is a member on here by the name of coiler who has run Volvo fh trucks for years who may be able to help with ideas (he seems as clued up as anyone on fh trucks) it might be worth sending a PM to him!
have you any pics you could post of the truck?
Moose:
what sort of weight are you pulling? the temp seems about right to me, as for the rev counter they can give problems as the dash clusters are not the best, there is a firm not far away from me that repair them (the pointers on the gauges can have a mind of their own)
there is a member on here by the name of coiler who has run Volvo fh trucks for years who may be able to help with ideas (he seems as clued up as anyone on fh trucks) it might be worth sending a PM to him!
have you any pics you could post of the truck?
I pull a B train, so all up i have 9 axles, all disc and on airbags.
Total Tare of the unit is quite high, around 20,000kg so can payload only 25,000kg max.
Most of what i cart is dry goods so very light, up to 8,000kg for a full load of toilet paper, 5,000kg for a full load of potato chips/crisps or about 3,000kg for an empty load of drums for the dairy fats… But then i also do lumber and frozen butter/cheese so can run max on a back load.
You know something is wrong when a loaded logger passes you and you only have 5000kg on… he has 28000kg…
Will post a pic soon, Signage is yet to go on… Christmas break they say… harden up i say!
LOL
It’s nothing to do with the weight ur pulling etc or the dash cluster etc it’s a sensor at fault & it’s in torque limiting mode.
truckers boy:
It’s nothing to do with the weight ur pulling etc or the dash cluster etc it’s a sensor at fault & it’s in torque limiting mode.
I never said it was the weight, I asked out of interest!
the dash clusters do give problems, not that is owt to do with it in this case, there is a common fault where the rev counter or speedo readings have no relation to what the truck is doing
which sensor should the op be looking at?
Yup, understand that truckers boy, was just saying what its used for… all good - no stress.
Here is a pic of the unit for those that are interested, signage still to come, as is trailers repaint…
offrd:
Yup, understand that truckers boy, was just saying what its used for… all good - no stress.Here is a pic of the unit for those that are interested, signage still to come, as is trailers repaint…
Now you’ve posted a picture I can see what the problem is,
Somebody stuck another trailer on while you weren’t looking, 
Ok it’s probably a sensor, we’ve just replaced a air boost sensor on one of our FH’s, I did notice a slight loss of power when it went wrong, not horrendous, but enough to notice.
Ah the second trailer!
No thats another truck and trailer that crashed into the back of me at the traffic lights!
Perhaps that’s the extra drag!
Thinking about the boost sensor, its also boost temperature sensor…
It could be the boost sensor part is fine but the temp sensor is out of spec thinking the boost is hot hence reducing the fuel delivery up in the rpm.
Would explain the mechanic saying the boost sensor was fine on the PC but the truck was torque limiting and he couldn’t do anything about it…
Just a thought…
Hopefully i run south tonight and get to the better mechanic tomorrow!!
Fingers crossed!
without a computer id be looking at the boost pressure / charge air temp sensor. obviusly i know it could be a stack of other things such as fuel lift pump, dirty sender unit filter etc. check the ohms (resistance) over the pins on boost sensor or even just bleep it out so what ur multi meter says. if you dont have much luck id be changing all of the fuel filters (sender unit filter, fuel filter, water seperator & i cant remember if the lift pump has a gorse filter or not).
cheers
UPDATE…!!
Well i made it to the workshop yesterday, hauled down at 44500kg so it was a bit of a slow trip being down in power and poor jakes…
The workshop had no available mechanics…
Lucky that im not too bad with a spanner…
So… I got the boost sensor and changed that… then whipped the rocker cover off and checked the Jake solenoid.
The solenoid was loose at junction between spindle and base, a place that it should not be able to be loose at… so i changed it too!
Quick look at the rockers, didn’t see anything really obvious…
Slapped it back together and gave it a run up. got the service manager to stick icos on it and check the exhaust brake operation, all good.
Ran home at 36000kg and it was much better… the jakes are not as good as i had thought they would be still… better than they had been!
It due for a service in a few thousand so it will get a top tune and anything else it may need then…
See how that goes, then look at remapping…
Was telling a mate that has a daf cf480 about remapping, “waste of money” he says…
The manufacturer made it as good as anyone will ever get it, how could a remap make it better than Volvo ever could.
Hmmm would love to prove him wrong…
You probably know already but a big Volvo problem is the gauze in the bottom of the fuel pick up getting blocked.
And it has symptoms very much like your describing, no smoke, no tickover problems, no warning lights, just simply no power. Might be worth a look, it will take you 5 minutes
kitbuilder123:
You probably know already but a big Volvo problem is the gauze in the bottom of the fuel pick up getting blocked.
And it has symptoms very much like your describing, no smoke, no tickover problems, no warning lights, just simply no power. Might be worth a look, it will take you 5 minutes
That was the fist thing the workshop did, they seemed to be so proud they knew what the problem was… but it wasn’t…
Power is not bad now, i hauled 46000kg over some serious roads this week, low range up, and low range down on the Jake!
Jake seems stronger at low rpm… gets weaker as the rpm rise… Bugger is jakes turn off over bumps and take a few seconds to come back on… on a hell grade it seems like hours before they come back on!