940 running problems. - Page 2

Sando · Oct 19th, 2010, 20:22

New radio suppression relay fitted. £33 from the local volvo dealer. Hasn't made a blind bit of difference.

Don't think it's the knock sensor, because when the missfire starts to occur, it's useally at about 2-2,500rpm it tends to worsen and then affect the wholr rev range culminating in a complete cut out. When trying to re-start I get nothing, except when I let go of the key it trys to run on, fires a couple of times and dies. Sometimes, if i'm quick, I can feather the throttle and get it running albeit roughly.

And then somehow, next time I try to use it, everything will be fine!

james 1992 940 · Oct 19th, 2010, 21:23

Have you tried the rpm sensor, located right behind the engine below the distributor. Read a few threads around about these becoming faulty both at the business end and along the cabling which gets plenty of stick due to its position. I noticed my cabling looks very sorry for itself and have added it to my to do list. I would imagine this could cause problems like yours if its signals werent getting to the ecu.

Also, you said you had read the fault codes when the engine was down previously; it may be worth rechecking for codes now.
Are you checking for fuel codes and ignition codes?

Sando · Oct 19th, 2010, 21:38

I fitted a complete new RPM sensor 6 or 7 months ago. It was the cause of the first breakdown. I haven't checked the fault codes again becasue my car doesn't have the socket type blink code reader. It has to run long enough for me to drive it to the local Volvo garage. Doh!

gpl1968 · Oct 19th, 2010, 21:51

Assuming your 940 has an OBD socket in the centre arm rest you could make your own fault code reader, like this:

Sando · Oct 20th, 2010, 07:27

Quote:

Originally Posted by gpl1968

Assuming your 940 has an OBD socket in the centre arm rest you could make your own fault code reader, like this:

Sorry, I think the link is missing.

gpl1968 · Oct 20th, 2010, 09:09

I didnt add a llink.
The picture and wiring diagram are fairly self explanatory and the testing proceedure is the same as you use for the earlier cars.
I made a parts list in an earlier thread: here

Sando · Oct 20th, 2010, 18:57

Sorry about that. I was looking at your original post at work. I guess their online security doesn't let the picutres through. Doh!

Sando · Oct 20th, 2010, 19:06

Used the car to get to work this morning. Ran well for maybe 10 minutes then the miss fire kicked in again. On the way home, no problems on my 15/20 commute with an added detour to pick up my little one.

I don't know if it's related, but there's a rectangular galvanised cover on the inner wing close to the ignition amplifier. After running the car, this is damn hot. Hot enough to burn my fingers if it's been a decent length run. It's held on with two torx screws and has on piece of conduit going into it.

I beleive this could be a resistor box of some sort for the injectors, and I'm fairly sure it shouldn't be so hot.

Any ideas anyone?

Sando · Oct 29th, 2010, 09:22

Any body know what these two things are?

Come on guys. I'm sure some of you gurus out there can idendify them.

gpl1968 · Oct 29th, 2010, 09:40

They are both resistor packs.
The left hand one is for the headlight dim-dip.
As they are effectively mounted in heat-sinks, I guess they are expected to get hot in use.

Oct 19th, 2010, 21:23	#12
james 1992 940 Junior Member Last Online: Dec 7th, 2010 22:26 Join Date: Sep 2010 Location: Oldbury West Midlands	Have you tried the rpm sensor, located right behind the engine below the distributor. Read a few threads around about these becoming faulty both at the business end and along the cabling which gets plenty of stick due to its position. I noticed my cabling looks very sorry for itself and have added it to my to do list. I would imagine this could cause problems like yours if its signals werent getting to the ecu. Also, you said you had read the fault codes when the engine was down previously; it may be worth rechecking for codes now. Are you checking for fuel codes and ignition codes? __________________ I'd prefer the top one but I know which one I'd end up with. Last edited by james 1992 940; Oct 19th, 2010 at 21:28. Reason: added question

Oct 19th, 2010, 21:51	#14
gpl1968 VOC Member Last Online: May 5th, 2024 23:42 Join Date: Jun 2007 Location: Wirral View Photos By: gpl1968	Assuming your 940 has an OBD socket in the centre arm rest you could make your own fault code reader, like this: __________________ Gavin 1997 945 CD (B230FK) [RIP: 1991 945 Turbo (B230FT) 1992 945 SE turbo (B200FT)]

Oct 20th, 2010, 09:09	#16
gpl1968 VOC Member Last Online: May 5th, 2024 23:42 Join Date: Jun 2007 Location: Wirral View Photos By: gpl1968	I didnt add a llink. The picture and wiring diagram are fairly self explanatory and the testing proceedure is the same as you use for the earlier cars. I made a parts list in an earlier thread: here __________________ Gavin 1997 945 CD (B230FK) [RIP: 1991 945 Turbo (B230FT) 1992 945 SE turbo (B200FT)]

Oct 29th, 2010, 09:40	#20
gpl1968 VOC Member Last Online: May 5th, 2024 23:42 Join Date: Jun 2007 Location: Wirral View Photos By: gpl1968	They are both resistor packs. The left hand one is for the headlight dim-dip. As they are effectively mounted in heat-sinks, I guess they are expected to get hot in use. __________________ Gavin 1997 945 CD (B230FK) [RIP: 1991 945 Turbo (B230FT) 1992 945 SE turbo (B200FT)]

Oct 19th, 2010, 20:22	#11
Sando New Member Last Online: Mar 3rd, 2011 21:12 Join Date: Oct 2010 Location: Retford	New radio suppression relay fitted. £33 from the local volvo dealer. Hasn't made a blind bit of difference. Don't think it's the knock sensor, because when the missfire starts to occur, it's useally at about 2-2,500rpm it tends to worsen and then affect the wholr rev range culminating in a complete cut out. When trying to re-start I get nothing, except when I let go of the key it trys to run on, fires a couple of times and dies. Sometimes, if i'm quick, I can feather the throttle and get it running albeit roughly. And then somehow, next time I try to use it, everything will be fine!

Oct 19th, 2010, 21:38	#13
Sando New Member Last Online: Mar 3rd, 2011 21:12 Join Date: Oct 2010 Location: Retford	I fitted a complete new RPM sensor 6 or 7 months ago. It was the cause of the first breakdown. I haven't checked the fault codes again becasue my car doesn't have the socket type blink code reader. It has to run long enough for me to drive it to the local Volvo garage. Doh!

Oct 20th, 2010, 18:57	#17
Sando New Member Last Online: Mar 3rd, 2011 21:12 Join Date: Oct 2010 Location: Retford	Sorry about that. I was looking at your original post at work. I guess their online security doesn't let the picutres through. Doh!

Oct 29th, 2010, 09:22	#19
Sando New Member Last Online: Mar 3rd, 2011 21:12 Join Date: Oct 2010 Location: Retford	Any body know what these two things are? Come on guys. I'm sure some of you gurus out there can idendify them.

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