2002 C70 Weird computer reset issue, poor running intermittent

dobrosailor · Post by **dobrosailor** » 02 Dec 2018, 08:07

2002 C70 with 143k mi. Well cared-for and daily driven car. In cold weather and occasionally, I go to start the car and it chuggs and fusses like a Mel Blanc Cartoon model T till it dies. I believe its flooding or a intermittent spark issue as there is a fuel smell to the exhaust when this happens. It will not start. No codes thrown except misfires on every cylinder. If I disconnect the battery and turn the key to start to discharge the capacitors, it fires right up and will drive for 3 to 4 weeks before it happens again. It happened twice end of last winter then ran great all summer. As soon as the snow hit, bang - its back. I have had it on VIDA and no secret codes or knowledge gained. Our local Volvo whisperer in town is baffled as are all of his mechanics. I got sent away with a sucks-to-be-you diagnosis.

Things tried, MAF sensor, turbo switch...

Any thoughts?

M

Post by **abscate** » 02 Dec 2018, 08:12

Where are hiding in NY?

I believe the first generation electronic throttle body is used on the C70 in 2002’ and that could have cratered at 143k

A bit early on miles bit not on time

VIDA is the right tool to diagnose that

Post by **wizechatmgr** » 02 Dec 2018, 19:20

VIDA has a great test for the ETM that is almost fool proof. Where are you in NY?

Post by **bmdubya1198** » 02 Dec 2018, 21:45

One more for ETM. I remember hearing about being able to test it with VIDA, I'd try that. Being that you're having a multi-cylinder misfire, it's definitely possible.
I'm pretty sure '02 uses the Magneti Marelli ETM still. Bosch didn't come until '03, IIRC.

dobrosailor · Post by **dobrosailor** » 03 Dec 2018, 03:52

I am in the Ithaca area. I had it hooked up to VIDA and they couldn't find anything. I will check to see if they did a ETM check. The ETM works very well right now, idles smooth, works repeatably through the throttle although it is pretty touchy, my kids are having a tough time learning the throttle as compared to our 1998 V70 which they like better. I'm just not sure how the ETM would screw things up in the computer. I have a friend wiht a junk yard of old volvos, might be able to try a different module

Sommerfeldt · Post by **Sommerfeldt** » 03 Dec 2018, 04:11

Could it be that there's a different reason you're running super rich for some reason? There are several things that can cause that, like a bad MAF/MAP, air leaks and O2 sensors gone rogue, in addition to the ETM. Resetting the ECU would reset the long term fuel trim along with everything else.

- S

Post by **abscate** » 03 Dec 2018, 04:17

I might be able to catch you in my cottage in Trumansburg sometime.

Has Brumsted given up on this or does he just not want to play?

When the ETM goes all kinds of ugliness happens. Someone here on the forum took my spare ETM for testing and then dropped all communication, ggggrrrrrrr.

The chance of a junkyard ETM working is about 20%, as the part number and software have to play together

dobrosailor · Post by **dobrosailor** » 03 Dec 2018, 04:31

Sommerfeldt wrote: ↑03 Dec 2018, 04:11 Could it be that there's a different reason you're running super rich for some reason? There are several things that can cause that, like a bad MAF/MAP, air leaks and O2 sensors gone rogue, in addition to the ETM. Resetting the ECU would reset the long term fuel trim along with everything else.

- S

So, between incidents, the car runs absolutely great, not running rich, no computer codes just happy Volvoing. I have a friend with a Volvo Junk yard so I have about 4 MAFs I've tried, it idles great so I doubt there is a air leak and there are no O2 sensor codes...

dobrosailor · Post by **dobrosailor** » 03 Dec 2018, 04:35

abscate wrote: ↑03 Dec 2018, 04:17 I might be able to catch you in my cottage in Trumansburg sometime.

Has Brumsted given up on this or does he just not want to play?

When the ETM goes all kinds of ugliness happens. Someone here on the forum took my spare ETM for testing and then dropped all communication, ggggrrrrrrr.

The chance of a junkyard ETM working is about 20%, as the part number and software have to play together

I play music in Watkins Glen so get through Tburg regularly. Brumsted was the Volvo whisperer I mentioned above who sent me packing with a sucks-to-be-you diagnosis. He has been great through all of this giving me torques and telling me where to get my head machined. Perhaps its time to convert it to a magnetic pickup, I know it's time is coming. I do love the car.

Post by **abscate** » 03 Dec 2018, 04:41

I'll try again to get my spare back. VIDA will tell you how the throttle sensors are playing but it does need to be in failure mode to learn, so that makes shop vs owner diagnosis tricky