Throttle issue

Dippydog · May 13th, 2018, 17:55

Having had a mate convert my throttle body to electric[to cure an occasional fluctuating idle] I've managed today to refit it.The problem is although the car started instantly the idle was surging about and foot hard down to the floor wouldn't pass 3500revs.it accelerated smoothly and without hesitation and when it hit 3500 revs it wasn't stuttering[as though it had hit a rev limiter]or anything.Does anyone know where my mate might have gone wrong or am I now looking at a separate issue?The only thing I know for sure he did do is leaving the rubber boot on the magnet would that be correct for starters after all the rubber boot has a shaped hole in the end to fit the shape of the spindle?Engine is a 2.4 n/a petrol and throttle body is Magnetti Marelli with the two TPS caps.

Dippydog · May 14th, 2018, 20:11

Had to move car today as they're coming to resurface the road tomorrow.On start up the revs didn't fluctuate quite so wildly as they did yesterday but still pretty badly.When I fetch it back home[possibly Weds]I'll remove throttle body again and see if can spot anything obvious[doubtful]before deciding what to do next.

ASt85 · May 15th, 2018, 09:15

The ECU has to "re-learn" its settings which can take a few stop/start - there a how to force the 850 ecu to re-learn here
http://www.volvotips.com/index.php/8...rn-procedures/

Exact procedure differs depending upon year of manufacture and model - the key is letting it idle for 5 or 10 minutes BEFORE you start driving it after doing anything with the throttle body.

It might be better to restart the process by either disconnecting the battery if you have the radio code, and carrying out a cold reset - battery disconnected for in excess of 15 minutes - short +ve and -ve battery leads/clamps, which makes sure that
memory is dumped. Reconnect the battery having turned the ignition key to positionII to prevent the airbags firing or you could pulling the ecu fuse for ten minutes if you don't want to mess about disconnecting the battery.

When you've got everything turned off - including the lights, if you have DLRs put the light switch to the sidelight position, or turn the small screw on the switch to the non DLR setting, start the car and let it idle for at least ten minutes in neutral with the hand brake off. If yours is an auto, then turn off the engine after those ten minutes and put it in drive with the wheels chocked so it can't roll forward, again letting it idle for ten minutes with the handbrake off. Apparently keeping the hand brake off means no warning light so the only current drain is from the various sensors/ecu/cem which makes it re-learn more quickly.

The process also works if you ever replace lambda sensors etc.

Dippydog · May 15th, 2018, 18:33

Thanks for that.Battery disconnect is no problem as I do indeed have the radio code.The car is a V70 first registered in Jan 2000 so presumably built in 1999.It's a 2.4 n/a petrol with manual gearbox so I'll turn the wheels into the curb to stop it rolling anywhere while the handbrake is off.I'll make written notes of all you've posted and give it a go this weekend,didn't realise that it'd have to "relearn"

hopefully that will sort it.

Dippydog · May 19th, 2018, 17:07

had the battery off for a couple of days to charge it,put it back on today and let car tickover[must've been at least 20mins as I got talking to my granddaughter] tickover was still fluctuating but once again less so than previously and today it revved to 4,000-still no stutter like it was hitting a rev limiter or anything-will give it a few more stop/starts and see if anything improves,if not I'll have to remove throttle body again and see if anything obviously wrong presents itself.

Dippydog · May 27th, 2018, 13:13

Nothing improved,so I took throttle body off again and although I didn't really know what I was looking at or doing had a bit of a fiddle.I reasoned that if I trashed it beyond fixable I could scrap the car[I have no great attachment to it like I have to my Omega]anyway put it back on today[battery disconnected while I was doing this]started car and idle was as smooth as it's ever been,let it tickover for 10-15mins and took it for a drive amazing! car now sings its way to 6,000revs[private road for this of course

]So it's now running like a Swiss watch and I realize that it's needed doing ever since I bought it

May 13th, 2018, 17:55	#1
Dippydog Premier Member Last Online: Today 19:11 Join Date: Jun 2016 Location: S****horpe	Throttle issue Having had a mate convert my throttle body to electric[to cure an occasional fluctuating idle] I've managed today to refit it.The problem is although the car started instantly the idle was surging about and foot hard down to the floor wouldn't pass 3500revs.it accelerated smoothly and without hesitation and when it hit 3500 revs it wasn't stuttering[as though it had hit a rev limiter]or anything.Does anyone know where my mate might have gone wrong or am I now looking at a separate issue?The only thing I know for sure he did do is leaving the rubber boot on the magnet would that be correct for starters after all the rubber boot has a shaped hole in the end to fit the shape of the spindle?Engine is a 2.4 n/a petrol and throttle body is Magnetti Marelli with the two TPS caps.

May 15th, 2018, 09:15	#3
ASt85 Premier Member Last Online: Apr 16th, 2024 14:11 Join Date: Aug 2010 Location: Walderslade....Kent	The ECU has to "re-learn" its settings which can take a few stop/start - there a how to force the 850 ecu to re-learn here http://www.volvotips.com/index.php/8...rn-procedures/ Exact procedure differs depending upon year of manufacture and model - the key is letting it idle for 5 or 10 minutes BEFORE you start driving it after doing anything with the throttle body. It might be better to restart the process by either disconnecting the battery if you have the radio code, and carrying out a cold reset - battery disconnected for in excess of 15 minutes - short +ve and -ve battery leads/clamps, which makes sure that memory is dumped. Reconnect the battery having turned the ignition key to positionII to prevent the airbags firing or you could pulling the ecu fuse for ten minutes if you don't want to mess about disconnecting the battery. When you've got everything turned off - including the lights, if you have DLRs put the light switch to the sidelight position, or turn the small screw on the switch to the non DLR setting, start the car and let it idle for at least ten minutes in neutral with the hand brake off. If yours is an auto, then turn off the engine after those ten minutes and put it in drive with the wheels chocked so it can't roll forward, again letting it idle for ten minutes with the handbrake off. Apparently keeping the hand brake off means no warning light so the only current drain is from the various sensors/ecu/cem which makes it re-learn more quickly. The process also works if you ever replace lambda sensors etc. __________________ The saddest moment is when the one who gave you the best memories....becomes a MEMORY V70 SE 2004 2.3L T5 Geartronic, C70 2005 2.0T Automatic, Sold 2.4l 20 Valve Automatic Torslander Sold 854 GLT 20v Auto Last edited by ASt85; May 15th, 2018 at 09:21.

May 27th, 2018, 13:13	#6
Dippydog Premier Member Last Online: Today 19:11 Join Date: Jun 2016 Location: S****horpe	Nothing improved,so I took throttle body off again and although I didn't really know what I was looking at or doing had a bit of a fiddle.I reasoned that if I trashed it beyond fixable I could scrap the car[I have no great attachment to it like I have to my Omega]anyway put it back on today[battery disconnected while I was doing this]started car and idle was as smooth as it's ever been,let it tickover for 10-15mins and took it for a drive amazing! car now sings its way to 6,000revs[private road for this of course]So it's now running like a Swiss watch and I realize that it's needed doing ever since I bought it

May 14th, 2018, 20:11	#2
Dippydog Premier Member Last Online: Today 19:11 Join Date: Jun 2016 Location: S****horpe	Had to move car today as they're coming to resurface the road tomorrow.On start up the revs didn't fluctuate quite so wildly as they did yesterday but still pretty badly.When I fetch it back home[possibly Weds]I'll remove throttle body again and see if can spot anything obvious[doubtful]before deciding what to do next.

May 15th, 2018, 18:33	#4
Dippydog Premier Member Last Online: Today 19:11 Join Date: Jun 2016 Location: S****horpe	Thanks for that.Battery disconnect is no problem as I do indeed have the radio code.The car is a V70 first registered in Jan 2000 so presumably built in 1999.It's a 2.4 n/a petrol with manual gearbox so I'll turn the wheels into the curb to stop it rolling anywhere while the handbrake is off.I'll make written notes of all you've posted and give it a go this weekend,didn't realise that it'd have to "relearn" hopefully that will sort it.

May 19th, 2018, 17:07	#5
Dippydog Premier Member Last Online: Today 19:11 Join Date: Jun 2016 Location: S****horpe	had the battery off for a couple of days to charge it,put it back on today and let car tickover[must've been at least 20mins as I got talking to my granddaughter] tickover was still fluctuating but once again less so than previously and today it revved to 4,000-still no stutter like it was hitting a rev limiter or anything-will give it a few more stop/starts and see if anything improves,if not I'll have to remove throttle body again and see if anything obviously wrong presents itself.

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