Non starter code 121 mass air flow? - Page 2

Laney760 · Aug 18th, 2020, 08:39

Speed signal missing code has now gone altogether for the first time ever, perhaps it is not a good idea to clear down the codes before diagnosis Dave, no codes to show RAC guy now, I guess I can't ge t the codes back until after it has started?

Laird Scooby · Aug 18th, 2020, 09:01

Quote:

Originally Posted by Laney760

Speed signal missing code has now gone altogether for the first time ever, perhaps it is not a good idea to clear down the codes before diagnosis Dave, no codes to show RAC guy now, I guess I can't ge t the codes back until after it has started?

You can still tell the RAC guy what the code was - i doubt he has a reader for it anyway as it's not OBD-II Ellie. The other thing is, i suspect that it was a symptom rather than a cause because the ECU is telling the fuel system to add more fuel and the injectors are responding but the engine isn't due to lack of fuel so it's throwing the MAF code because it doesn't believe the MAF - it thinks the MAF is wrong because the engine should have responded if you get my meaning?

On a lot of early 940s, the RSR feeds the igntion coil as well as the injectors, many later ones the RSR only feeds the injectors so it may be worth his while giving a squirt of Easy Start to see if the engine (and therefore the ignition system) is capable of running. However to be 100% sure, he'd need to also check he has a +12V feed to the coil before trying this.

Hopefully the RAC guy is clued up on older Volvos or he might not be able to get anywhere near the problem!

Laney760 · Aug 18th, 2020, 09:15

Cheers Dave. Yes I know they can't read my codes. I also have a good spare rsr in my dash. Thanks for the heads up about the MAF code. The rev counter is jiggy when I crank her by the way

Laney760 · Aug 18th, 2020, 09:41

Cheers Dave. Yes I know they can't read my codes. I also have a good spare rsr in my dash. Thanks for the heads up about the MAF code. The rev counter is jiggy when I crank her by the way .. RAC guy has just been, no spark, nowt to do with fuel. He wriggled the RSR in the same manner as I did and made sure it was pushed in properly and she fires up, time and time again, problem solved for now! My RSR is hanging sort of since I fitted the new one I can't get it back into its holder and not can anyone else. I will get the garage to get back in place properly. THANK YOU all, back to my sickbed!

Laird Scooby · Aug 18th, 2020, 12:27

Quote:

Originally Posted by Laney760

Cheers Dave. Yes I know they can't read my codes. I also have a good spare rsr in my dash. Thanks for the heads up about the MAF code. The rev counter is jiggy when I crank her by the way .. RAC guy has just been, no spark, nowt to do with fuel. He wriggled the RSR in the same manner as I did and made sure it was pushed in properly and she fires up, time and time again, problem solved for now! My RSR is hanging sort of since I fitted the new one I can't get it back into its holder and not can anyone else. I will get the garage to get back in place properly. THANK YOU all, back to my sickbed!

I thought it would be something simple, almost had to be to suddenly play up like that!

Glad it's up and running again, chances are he was somewhat rougher with his wriggling of the RSR if you're not firing on all cylinders yourself.
Hope you feel better soon!

mjk164 · Aug 18th, 2020, 14:11

Hi Laney, I have been following this thread as it interested me, although my car is a 960, but this radio suppression relay (RSR) is a favorite for causing just your sort of problem. In the 960 there are 2 similar relays, attached very close to the n/s suspension unit. As in the 940 series, these get their 12v supply direct from the battery + and independent of the ignition switch. Anything slightly worn or dodgy in these relay contacts will cause a stop or intermittent misfires; I always keep a new spare in the glove box and have used it at least twice in about 20 years! Have a look at the wiring diagram and you can see why. You can take the cover off the relay and take it apart and stone in the relay contacts for another lease of life, but my advise is to get a new one and clean up the one you take out as a spare.
Glad you got it sorted.

Laird Scooby · Aug 18th, 2020, 14:19

Quote:

Originally Posted by mjk164

Hi Laney, I have been following this thread as it interested me, although my car is a 960, but this radio suppression relay (RSR) is a favorite for causing just your sort of problem. In the 960 there are 2 similar relays, attached very close to the n/s suspension unit. As in the 940 series, these get their 12v supply direct from the battery + and independent of the ignition switch. Anything slightly worn or dodgy in these relay contacts will cause a stop or intermittent misfires; I always keep a new spare in the glove box and have used it at least twice in about 20 years! Have a look at the wiring diagram and you can see why. You can take the cover off the relay and take it apart and stone in the relay contacts for another lease of life, but my advise is to get a new one and clean up the one you take out as a spare.
Glad you got it sorted.

That's good advice, what i plan to do with mine next time it plays up is to remove it, cut the bespoke Volvo cradle off the wiring and fit a generic 4-pin relay cradle and generic 4-pin, 30A relay.
That way i can carry a generic relay, if i'm unfortunate enough that both the relay in there and the generic relay fail i can pick one up anywhere that's open. Meanwhile easier to bypass to get running with a short link with a 1/4" male spade/Lucar terminal crimped on each end.

Will do a write-up when i do it with some pretty pictures.

Laney760 · Aug 18th, 2020, 15:59

Gone again now that I am on a motorway, spark breaking down, stopping and starting and stalling. Waiting for RAC. I have a spare RSR but I am not really sure it is that because before the guy tweaked that relay he fiddled around with the coil. So when it fired up I asked him how he knew it was the RSR and he said the coil either works or it doesn't but not sure it's not wiring to the coil now

Laney760 · Aug 18th, 2020, 16:14

The RSR that's in there was bought new from Volvo's two years ago, my spare in the dash which turned out to be not the problem and not faulty is the cars original 2997 one. If they get me going I am going to make them follow me again for a while up the motorway. I had planned to book the car in anyway to get this all checked out as I was highly dubios that my checking the relay was pushed home fully was any different to the RAC guys. I suspect the wiring to the coil if it is true that a coil either works or it doesn't

Laird Scooby · Aug 18th, 2020, 17:33

Just a hunch Ellie, try wiggling the coil leads and make sure the main HT lead is pushed into the coil and try starting it.

Aug 18th, 2020, 08:39	#11
Laney760 VOC Member Last Online: Mar 18th, 2024 12:17 Join Date: Jul 2008 Location: Henley on Thames	Speed signal missing code has now gone altogether for the first time ever, perhaps it is not a good idea to clear down the codes before diagnosis Dave, no codes to show RAC guy now, I guess I can't ge t the codes back until after it has started? __________________ [IMG]Volvo2 by Strider'swoman, on Flickr[/IMG] Current '96 945 2.3 lpt - Aurigas, tailgate spoiler, sports grille, lpg fuelled Previous '88 764 TD, '92 945 TD, '88 745, '81 244 DL

Aug 18th, 2020, 09:15	#13
Laney760 VOC Member Last Online: Mar 18th, 2024 12:17 Join Date: Jul 2008 Location: Henley on Thames	Cheers Dave. Yes I know they can't read my codes. I also have a good spare rsr in my dash. Thanks for the heads up about the MAF code. The rev counter is jiggy when I crank her by the way __________________ [IMG]Volvo2 by Strider'swoman, on Flickr[/IMG] Current '96 945 2.3 lpt - Aurigas, tailgate spoiler, sports grille, lpg fuelled Previous '88 764 TD, '92 945 TD, '88 745, '81 244 DL

Aug 18th, 2020, 09:41	#14
Laney760 VOC Member Last Online: Mar 18th, 2024 12:17 Join Date: Jul 2008 Location: Henley on Thames	Cheers Dave. Yes I know they can't read my codes. I also have a good spare rsr in my dash. Thanks for the heads up about the MAF code. The rev counter is jiggy when I crank her by the way .. RAC guy has just been, no spark, nowt to do with fuel. He wriggled the RSR in the same manner as I did and made sure it was pushed in properly and she fires up, time and time again, problem solved for now! My RSR is hanging sort of since I fitted the new one I can't get it back into its holder and not can anyone else. I will get the garage to get back in place properly. THANK YOU all, back to my sickbed! __________________ [IMG]Volvo2 by Strider'swoman, on Flickr[/IMG] Current '96 945 2.3 lpt - Aurigas, tailgate spoiler, sports grille, lpg fuelled Previous '88 764 TD, '92 945 TD, '88 745, '81 244 DL

Aug 18th, 2020, 15:59	#18
Laney760 VOC Member Last Online: Mar 18th, 2024 12:17 Join Date: Jul 2008 Location: Henley on Thames	Gone again now that I am on a motorway, spark breaking down, stopping and starting and stalling. Waiting for RAC. I have a spare RSR but I am not really sure it is that because before the guy tweaked that relay he fiddled around with the coil. So when it fired up I asked him how he knew it was the RSR and he said the coil either works or it doesn't but not sure it's not wiring to the coil now __________________ [IMG]Volvo2 by Strider'swoman, on Flickr[/IMG] Current '96 945 2.3 lpt - Aurigas, tailgate spoiler, sports grille, lpg fuelled Previous '88 764 TD, '92 945 TD, '88 745, '81 244 DL

Aug 18th, 2020, 16:14	#19
Laney760 VOC Member Last Online: Mar 18th, 2024 12:17 Join Date: Jul 2008 Location: Henley on Thames	The RSR that's in there was bought new from Volvo's two years ago, my spare in the dash which turned out to be not the problem and not faulty is the cars original 2997 one. If they get me going I am going to make them follow me again for a while up the motorway. I had planned to book the car in anyway to get this all checked out as I was highly dubios that my checking the relay was pushed home fully was any different to the RAC guys. I suspect the wiring to the coil if it is true that a coil either works or it doesn't __________________ [IMG]Volvo2 by Strider'swoman, on Flickr[/IMG] Current '96 945 2.3 lpt - Aurigas, tailgate spoiler, sports grille, lpg fuelled Previous '88 764 TD, '92 945 TD, '88 745, '81 244 DL

Aug 18th, 2020, 14:11	#16
mjk164 VOC Member Last Online: May 4th, 2024 06:19 Join Date: Aug 2006 Location: Hounslow West London	Hi Laney, I have been following this thread as it interested me, although my car is a 960, but this radio suppression relay (RSR) is a favorite for causing just your sort of problem. In the 960 there are 2 similar relays, attached very close to the n/s suspension unit. As in the 940 series, these get their 12v supply direct from the battery + and independent of the ignition switch. Anything slightly worn or dodgy in these relay contacts will cause a stop or intermittent misfires; I always keep a new spare in the glove box and have used it at least twice in about 20 years! Have a look at the wiring diagram and you can see why. You can take the cover off the relay and take it apart and stone in the relay contacts for another lease of life, but my advise is to get a new one and clean up the one you take out as a spare. Glad you got it sorted.

Aug 18th, 2020, 17:33	#20
Laird Scooby Premier Member Last Online: Today 18:35 Join Date: May 2012 Location: Lakenheath	Just a hunch Ellie, try wiggling the coil leads and make sure the main HT lead is pushed into the coil and try starting it. __________________ Cheers Dave Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........

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