Car nearly dies when pressing clutch

Anadinolin · Mar 6th, 2016, 14:24

Hiya, not sure what's going on, but whilst changing gears and sometimes slowing down at traffic lights, the cars revs drop below idle and as low as 100-200 rpm. It dosent happen all the time either.

I cannot see anything obvious...

classicswede · Mar 6th, 2016, 15:22

Carb or injection? Turbo?

Anadinolin · Mar 6th, 2016, 16:13

B18u monopoint hehe

dcw · Mar 6th, 2016, 17:55

Does it recover itself? I have had this on occasion over the years on the various 480s I have had: you de-clutch to change gear and the car nearly stalls, then recovers itself.

I have found that quite often cleaning the throttle body helps, to ensure that the valve is opening and closing cleanly.

Don't know if that's any help at all...

Hope you can sort it!

David

Clan · Mar 6th, 2016, 18:30

Quote:

Originally Posted by Anadinolin

Hiya, not sure what's going on, but whilst changing gears and sometimes slowing down at traffic lights, the cars revs drop below idle and as low as 100-200 rpm. It dosent happen all the time either.

I cannot see anything obvious...

most likely the idle control motor not working . can you see the throttle open on the "carb" ready for the next cold start when someone turns the engine off ?

dingov70 · Mar 6th, 2016, 20:07

Hum , just like to ask does the engine revs remain low as long as the clutch pedal is depressed or does it rise of its own will ? . The reason for asking was a car came through me hands recently that the clever people with laptops could not cure . With the engine running & the bonnet open , the owner pressed the clutch pedal & i could see the crank pulley move " forwards " because the crank thrust bearigns had worn through , a symptom of being used as a taxi for many years . It is a very quick check to make & eliminate the engine binding up when the crank moves , it is almost the same as the engine seizing in effect .

Clan · Mar 6th, 2016, 20:35

Quote:

Originally Posted by dingov70

Hum , just like to ask does the engine revs remain low as long as the clutch pedal is depressed or does it rise of its own will ? . The reason for asking was a car came through me hands recently that the clever people with laptops could not cure . With the engine running & the bonnet open , the owner pressed the clutch pedal & i could see the crank pulley move " forwards " because the crank thrust bearigns had worn through , a symptom of being used as a taxi for many years . It is a very quick check to make & eliminate the engine binding up when the crank moves , it is almost the same as the engine seizing in effect .

The idle control should overcome the drop in rpm easily even if the thrust washers are worn away , worth checking out too if the throttle motor is working ok .

captainslow · Mar 6th, 2016, 22:19

Is it an electronic speedo model? If so & the speedo is not working due to loose connection then I have experienced that causing this behaviour on my previous 480.

Anadinolin · Mar 7th, 2016, 07:51

It's a cable speedo, unfortunately that has snapped as of two nights ago.

The rpms recover themselves back to the normal idle (900rpm) and the idle is stable in neutral and with clutch depressed. Car starts first time aswell.

I will need to check that the butterfly has opened next weekend as it is now in its weekly lockup and I'm going to Plymouth for work this week.

How would I check crank thrust bearings and washers/crank pulley what am I looking for?

NI_Volvo_Nut · Mar 7th, 2016, 11:11

Had this on my 440, I got a module from a Renault breakers. As per what Clan says

Mar 6th, 2016, 14:24	#1
Anadinolin VOC Member Last Online: Jun 20th, 2022 14:32 Join Date: Oct 2009 Location: Upminster View Photos By: Anadinolin	Car nearly dies when pressing clutch Hiya, not sure what's going on, but whilst changing gears and sometimes slowing down at traffic lights, the cars revs drop below idle and as low as 100-200 rpm. It dosent happen all the time either. I cannot see anything obvious... __________________ what good music deserves is full deep bass to give it warmth. the stock volvo sub works....just at high volumes Drum n Bass and dubstep

Mar 6th, 2016, 15:22	#2
classicswede Trader Volvo in my veins Last Online: Yesterday 22:36 Join Date: Dec 2004 Location: Anglesey	Carb or injection? Turbo? __________________ http://www.classicswede.org www.classicswede.co.uk

Mar 6th, 2016, 16:13	#3
Anadinolin VOC Member Last Online: Jun 20th, 2022 14:32 Join Date: Oct 2009 Location: Upminster View Photos By: Anadinolin	B18u monopoint hehe __________________ what good music deserves is full deep bass to give it warmth. the stock volvo sub works....just at high volumes Drum n Bass and dubstep

Mar 6th, 2016, 17:55	#4
dcw VOC Member Last Online: May 1st, 2024 19:45 Join Date: Jan 2007 Location: YORK	Does it recover itself? I have had this on occasion over the years on the various 480s I have had: you de-clutch to change gear and the car nearly stalls, then recovers itself. I have found that quite often cleaning the throttle body helps, to ensure that the valve is opening and closing cleanly. Don't know if that's any help at all... Hope you can sort it! David __________________ VOC 400 Series Register Keeper The current fleet: 1997 440 LE, 1996 460 CD, 1994 480 GT and 2007 V50 SE Sport

Mar 6th, 2016, 20:07	#6
dingov70 Master Member Last Online: Yesterday 05:35 Join Date: Jan 2015 Location: Blackpool	Hum , just like to ask does the engine revs remain low as long as the clutch pedal is depressed or does it rise of its own will ? . The reason for asking was a car came through me hands recently that the clever people with laptops could not cure . With the engine running & the bonnet open , the owner pressed the clutch pedal & i could see the crank pulley move " forwards " because the crank thrust bearigns had worn through , a symptom of being used as a taxi for many years . It is a very quick check to make & eliminate the engine binding up when the crank moves , it is almost the same as the engine seizing in effect . __________________ To stupidity & beyond

Mar 6th, 2016, 22:19	#8
captainslow Member Last Online: Nov 29th, 2018 22:59 Join Date: Mar 2010 Location: St Andrews	Is it an electronic speedo model? If so & the speedo is not working due to loose connection then I have experienced that causing this behaviour on my previous 480.

Mar 7th, 2016, 07:51	#9
Anadinolin VOC Member Last Online: Jun 20th, 2022 14:32 Join Date: Oct 2009 Location: Upminster View Photos By: Anadinolin	It's a cable speedo, unfortunately that has snapped as of two nights ago. The rpms recover themselves back to the normal idle (900rpm) and the idle is stable in neutral and with clutch depressed. Car starts first time aswell. I will need to check that the butterfly has opened next weekend as it is now in its weekly lockup and I'm going to Plymouth for work this week. How would I check crank thrust bearings and washers/crank pulley what am I looking for? __________________ what good music deserves is full deep bass to give it warmth. the stock volvo sub works....just at high volumes Drum n Bass and dubstep

Mar 7th, 2016, 11:11	#10
NI_Volvo_Nut Volvologist Last Online: Dec 6th, 2023 11:13 Join Date: Aug 2008 Location: Bangor - Norn Iron View Photos By: NI_Volvo_Nut	Had this on my 440, I got a module from a Renault breakers. As per what Clan says __________________ What's the matter with the car I'm driving? Can't you tell that it's out of style? Should I get a set of white wall tires? Are you gonna cruise the miracle mile?

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