V70 hesitation on accelerating

monkeh · Nov 7th, 2012, 20:51

Can anyone give me a pointer on why my v70 2.5 20v hesitates on acceleration? Warmed up it comes and goes, but when cold and warming up its very lethargic. Could it be a fuel issue? No codes thrown up, but I have the problem with the TRACS and abs light on, An issue I am waiting for spares for to fix.

green van man · Nov 7th, 2012, 22:29

No idea what your trouble is but if its any help my V70 diesel had a flat spot when accelerating when I baught it, no fault lights showing, turned out to be MAF sensor faulty. £300 or so later was back to flying. Told MAF sensor was only thing that would give the symtoms and not show a fault light.

Paul.

deathrider311271 · Nov 7th, 2012, 23:20

Quote:

Originally Posted by monkeh

Can anyone give me a pointer on why my v70 2.5 20v hesitates on acceleration? Warmed up it comes and goes, but when cold and warming up its very lethargic. Could it be a fuel issue? No codes thrown up, but I have the problem with the TRACS and abs light on, An issue I am waiting for spares for to fix.

from my experience its all linked to your ABS/TRACS issue

scutyde · Nov 8th, 2012, 08:22

ABS/TRACS -> bad solder points in the unit?
Which year is yours? 99er and up models are known for problems due to the e-gas throttle unit.

Cristian

capt jack · Nov 8th, 2012, 08:34

Before looking for complicated and expensive explanations and solutions it's a good idea to consider the simple stuff first.

For what they cost, try some new spark plugs and an air filter. Total cost less than £20.

If the car has a distributor cap, rotor and plug leads then either replace or at least clean up the contacts. If yours is a 99MY or later it's possibly an ETM car, and so may not have a dissy and rotor in the conventional sense.

Get some carb cleaner and manually clean the throttle body. If it's never been done you'll be amazed at how much gunk accumulates. Read the instructions on the carb cleaner tin carefully.

Clean and remake the earth connections under the bonnet - one on the engine block and one near the battery.

Finally, drop some injector cleaner in the fuel tank next time you fill up.

We had a not dissimilar set of symptoms with our S70 recently, and the above steps cured it.

One last thought - are you certain the thermostat is in good order? The temperature should be at the 3-o'clcok position within a couple of miles, even on a cold morning, and the heater nice and hot. If this doesn't happen then you need a new thermostat. A dodgy thermostat will definitely affect cold running performance. £10 from GSF, £20 for a genuine Volvo one. Don't forget the rubber sealing ring too.

Cheers

Jack

Luxobarge · Nov 8th, 2012, 09:36

Suggestions is the above post are all very good ones, but personally I'd sort out the ABS problem first - as mentioned, most likely by re-soldering the unit.

Reason I say this is that the ABS unit does provide at least one signal feed (vehicle speed) to the main engine ECU, so if the ABS unit is playing silly b*ggers then it's possible that it is messing up the control of the main engine ECU too.

All the best

capt jack · Nov 8th, 2012, 10:13

Good advice there from Luxo.

One thing to do that might help clarify how far the ABS unit is at fault would simply be to disconnect it I guess and see if that affects anything.

The ABS and TRACS won't work of course, neither will the speedo. I mentioned our S70, which also had ABS issues just before the poor running problems started, but the car was certainly driveable with the ABS module disconnected.

If there's a poor idle when cold then that too might suggest that the problem isn't related to the ABS as the car isn't moving and so can't get any signal from the ABS unit about the roadspeed!

Cheers

Jack

BTW: If you don't fancy trying to fix the ABS module yourself, there are a number of companies offering a good repair-exchange service.

monkeh · Nov 10th, 2012, 16:08

Found a few Vacuum leaks, Fixed them, seems to be a bit better, Tracs fault was repaired a day later, and thats gone now, (usual dry joints inside the unit)

N Gauge Bob · Feb 20th, 2016, 10:05

Quote:

Originally Posted by monkeh

Can anyone give me a pointer on why my v70 2.5 20v hesitates on acceleration? Warmed up it comes and goes, but when cold and warming up its very lethargic. Could it be a fuel issue? No codes thrown up, but I have the problem with the TRACS and abs light on, An issue I am waiting for spares for to fix.

Mine is the exact opposite. It is fine when cold but starts jerking at around 10 miles, at which time the bottom right hand "gearbox sign" illuminates on the dash panel. Mine is a v70 1999 I assume 20v as I haven't got the log book yet, fuel injection type.

V70Zig · Feb 20th, 2016, 11:08

Quote:

Originally Posted by N Gauge Bob

Mine is the exact opposite. It is fine when cold but starts jerking at around 10 miles, at which time the bottom right hand "gearbox sign" illuminates on the dash panel. Mine is a v70 1999 I assume 20v as I haven't got the log book yet, fuel injection type.

Think you'll find that is the engine management light. There will be codes stored so get a reader on it......beats guessing

Nov 7th, 2012, 20:51	#1
monkeh Pain in the backside Last Online: Yesterday 21:15 Join Date: Mar 2007 Location: Newport	V70 hesitation on accelerating Can anyone give me a pointer on why my v70 2.5 20v hesitates on acceleration? Warmed up it comes and goes, but when cold and warming up its very lethargic. Could it be a fuel issue? No codes thrown up, but I have the problem with the TRACS and abs light on, An issue I am waiting for spares for to fix. __________________ 'Designed by a computer, built by a robot, and driven by a f***ing nutter' '09 XC70 SE - 2" lift, D5 225bhp, poverty spec '18 V60 Twin Engine R Design - 290bhp

Nov 8th, 2012, 08:22	#4
scutyde Retrofit master Last Online: Mar 28th, 2022 10:14 Join Date: Mar 2010 Location: Berlin	ABS/TRACS -> bad solder points in the unit? Which year is yours? 99er and up models are known for problems due to the e-gas throttle unit. Cristian __________________ Volvo 850 2.5 20V MY95 Pictures Here what I retroffited so far List

Nov 8th, 2012, 08:34	#5
capt jack VOC Member Last Online: May 26th, 2024 19:26 Join Date: Jun 2006 Location: Selby, North Yorkshire	Hesitation when cold Before looking for complicated and expensive explanations and solutions it's a good idea to consider the simple stuff first. For what they cost, try some new spark plugs and an air filter. Total cost less than £20. If the car has a distributor cap, rotor and plug leads then either replace or at least clean up the contacts. If yours is a 99MY or later it's possibly an ETM car, and so may not have a dissy and rotor in the conventional sense. Get some carb cleaner and manually clean the throttle body. If it's never been done you'll be amazed at how much gunk accumulates. Read the instructions on the carb cleaner tin carefully. Clean and remake the earth connections under the bonnet - one on the engine block and one near the battery. Finally, drop some injector cleaner in the fuel tank next time you fill up. We had a not dissimilar set of symptoms with our S70 recently, and the above steps cured it. One last thought - are you certain the thermostat is in good order? The temperature should be at the 3-o'clcok position within a couple of miles, even on a cold morning, and the heater nice and hot. If this doesn't happen then you need a new thermostat. A dodgy thermostat will definitely affect cold running performance. £10 from GSF, £20 for a genuine Volvo one. Don't forget the rubber sealing ring too. Cheers Jack Last edited by capt jack; Nov 8th, 2012 at 08:39.

Nov 8th, 2012, 09:36	#6
Luxobarge Premier Member Last Online: Today 07:53 Join Date: Jan 2011 Location: Horne (Nr. Horley)	Suggestions is the above post are all very good ones, but personally I'd sort out the ABS problem first - as mentioned, most likely by re-soldering the unit. Reason I say this is that the ABS unit does provide at least one signal feed (vehicle speed) to the main engine ECU, so if the ABS unit is playing silly bggers then it's possible* that it is messing up the control of the main engine ECU too. All the best __________________ Some people are like Slinkies, they serve no useful purpose but they still bring a smile to your face when you push them downstairs.

Nov 10th, 2012, 16:08	#8
monkeh Pain in the backside Last Online: Yesterday 21:15 Join Date: Mar 2007 Location: Newport	Found a few Vacuum leaks, Fixed them, seems to be a bit better, Tracs fault was repaired a day later, and thats gone now, (usual dry joints inside the unit) __________________ 'Designed by a computer, built by a robot, and driven by a f***ing nutter' '09 XC70 SE - 2" lift, D5 225bhp, poverty spec '18 V60 Twin Engine R Design - 290bhp

Nov 7th, 2012, 22:29	#2
green van man Premier Member Last Online: Apr 11th, 2024 09:21 Join Date: Nov 2012 Location: Ffos y Ffin	No idea what your trouble is but if its any help my V70 diesel had a flat spot when accelerating when I baught it, no fault lights showing, turned out to be MAF sensor faulty. £300 or so later was back to flying. Told MAF sensor was only thing that would give the symtoms and not show a fault light. Paul.

Nov 8th, 2012, 10:13	#7
capt jack VOC Member Last Online: May 26th, 2024 19:26 Join Date: Jun 2006 Location: Selby, North Yorkshire	Good advice there from Luxo. One thing to do that might help clarify how far the ABS unit is at fault would simply be to disconnect it I guess and see if that affects anything. The ABS and TRACS won't work of course, neither will the speedo. I mentioned our S70, which also had ABS issues just before the poor running problems started, but the car was certainly driveable with the ABS module disconnected. If there's a poor idle when cold then that too might suggest that the problem isn't related to the ABS as the car isn't moving and so can't get any signal from the ABS unit about the roadspeed! Cheers Jack BTW: If you don't fancy trying to fix the ABS module yourself, there are a number of companies offering a good repair-exchange service.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)