1998 V70 Died while driving - won't start, no spark

Post by **cn90** » 01 Jul 2014, 13:00

- 1998 has no immobilizer, which is used in later models.

- Relay: mark each of them 1, 2, 3, etc. and swap as test as you wish. Take a photo so you can always go back to the stock setup.

Scan for OBD-II codes again and post them here!

kjhiggins · Post by **kjhiggins** » 02 Jul 2014, 12:40

I'm not getting any new OBD-II codes from my attempts to start the car. I swapped the main relay with the identical one next to it with no difference. I received an answer about the 'W' mode light when the ignition is on and this appears to be normal. I checked the resistances across the cam sensor and the crank sensor leads and I get the same resistances at the corresponding pins in the ECU connector so the wiring between the sensors and the ECU appears to be good.

I found a table of expected voltages at the various ECU pins when the ignition is on - can I check for these with the ECU out or do I need to use some sort of connector that allows me to probe the voltages while the ECU is connected?

Thanks again!

kjhiggins · Post by **kjhiggins** » 06 Jul 2014, 12:50

An Update: I purchased an ECU on Ebay with the correct numbers and swapped it in - success for a short while! It took a bit of cranking to get it to start but once it started I let it idle for about 30 minutes to charge the battery and then took it out for a spin. It ran great for about a mile then the same thing happened - stalled without sputtering and I can't get it to start, again with no spark. I'm going to swap my original cam sensor and coil back into the car in case there is something wrong with the ones I got from the wrecking yard but does anyone have any other ideas as to what is wrong? I checked a number of ground straps but is there one in particular I should check for the ECU?

Thanks for everyone's help.
Kelly

Post by **cn90** » 06 Jul 2014, 14:58

Maybe bad fuel pump (sorry I have not read all the posts)?

kjhiggins · Post by **kjhiggins** » 06 Jul 2014, 15:09

There is fuel pressure at the fuel pressure at the rail so fuel pump appears to be good.

To summarize: Car stalled while driving, no spark. Changed cam sensor (used), crank sensor (new), coil (used) - still no spark. Changed ECU (used) - started and ran great for about two miles but then stalled with no spark.

I swapped the original cam sensor and coil back in but still no spark. Is there something that could be frying the ECU after a couple of miles, or some system that gets checked and comes back bad so it shuts the car down? There are no new codes stored.

johnhon · Post by **johnhon** » 27 Jul 2014, 05:13

Have you found a solution yet? I have a 98 xc70 with 225,000 mi. doing the same thing. Please post if you figure this out. Thanks.

Post by **abscate** » 27 Jul 2014, 06:09

We have had three recent posters report cars with spark, but new coils fixed a no-start condition.

Coils don't seem to be failing digitally, they can give spark and still no-start, FWIW

johnhon · Post by **johnhon** » 28 Jul 2014, 09:35

Thanks, abscate, but I installed a new Bosch coil pack 2 months ago with new plugs, wires, dist. rotor, timing belt. Any other ideas?

Post by **abscate** » 28 Jul 2014, 12:14

Pull the ECU and look underneath at all the grounds. I think every ground on the engine and under the battery needs checking too. There are a lot of them.

Sorry for the misdirect, I missed new coil info.

You can grab the Volvo wiring diagram off the internet ...apologies ,but , by agreement with Volvo , MVS does not host that info here.

Do you have no spark at all 5 cylinders ?

Ps...to the gurus...does the immobilizer let you run for a few minutes then quit or will it give a strict no-start?

kjhiggins · Post by **kjhiggins** » 28 Jul 2014, 17:05

Pulled the wiring harness from the engine compartment and upon close inspection I found:

There are a couple of places where the insulation is worn through but this is the only place I actually see scorching as though it was shorting. I'm not sure, but this might be where one of the cable ties held the wires to the plastic tray. I traced the worn wires to an injector, the crank sensor, and an oxygen sensor.

My plan now is to clean the wires and use spray-on clear insulation before putting it back in the car. My alternate plan is to go the the local wrecking yard that received a V70 last week with 100k less miles than mine and pull its harness. Any thoughts on either approach? Should I cut out the bad parts and solder the wires back together with heat-shrink tubing?

1998 V70 Died while driving - won't start, no spark

Re: 1998 V70 Died while driving - won't start, no spark