Bad ecu ground? 855r 97 no spark Topic is solved

[AndreasJJ]

Checked the ect sensor now..and there was one damaged wire and alot of corrosion

Fix this. Any corrosion can cause a bad signal to the ECU. An open , or high resistance ECT circuit will cause a no start, especially when it's cold.

It doesn't cause no spark, it over-fuels, to the point of flooding.

I bet you'll find the CEL bulb pulled, instead of just burnt out.

Yes i cleaned the connector as best i could and tried starting no difference.probably gonna buy a new sensor anyway

But still the what can cause the no spark any pinouts i should read at the ecu?..Any ground wires? But i also read somewhere If it is a ecu ground the relay on the fan shroud wouldn’t work but u don’t know how true that is but worth a mention..something is not signaling right

[Chuck W]

Fix the ECT sensor and it's connector. Replace the connector if you need to (I've replaced ours with WeatherPak type connectors, as the stock ones are long disintegrated. This should be your primary focus.

I had the SAME issue that presented as a no spark, but it was the ECT in the end. It happened when it was very cold. Replaced the ECT and the connector, the car fired right up.

As far as grounds, that I remember without going out to check. . There are 2 between the engine and the firewall. One on the ECU harness behind the right side headlamp. (Under it actually) and there is one that attaches on the driver side on the frame rail, subframe and transmission/engine.

[AndreasJJ]

Fix the ECT sensor and it's connector. Replace the connector if you need to (I've replaced ours with WeatherPak type connectors, as the stock ones are long disintegrated. This should be your primary focus.

I had the SAME issue that presented as a no spark, but it was the ECT in the end. It happened when it was very cold. Replaced the ECT and the connector, the car fired right up.

As far as grounds, that I remember without going out to check. . There are 2 between the engine and the firewall. One on the ECU harness behind the right side headlamp. (Under it actually) and there is one that attaches on the driver side on the frame rail, subframe and transmission/engine.

Yeah no absolutely im gonna fix it going to check with my local Volvo parts dealer i he has a new sensor somewhere partly becuse the wires are damaged and the sensor it self don’t look to great atleast on the outside..probably going to do it tomorrow If the car isn’t burried in snow hahaha

I only have found the one on top of the block that goes to the firewall and the one that the ignition coil goes to like at the fender..couldn’t find one under the headlight,any specific part of the framerail you know of? If you don’t its okay i can probably find out myself just that i don’t think iv’e seen one there either

[scot850]

The battery -ve wire has 2 ground connectors, one behind and maybe hidden under the battery tray behind the LH headlight, and a second one that runs to the front of the engine block.

Some cars have a ground running from the back of the engine from the top of the cylinder head to around the middle of the firewall.

Volvo has more or less grounds depending on the year of P80 from 92-00 years.

Neil.

[Chuck W]

Wait...

THIS is the same car, correct?

[AndreasJJ]

Wait...

THIS is the same car, correct?

Hahaha what? Yes im talking about the same car as in the beggining

[Chuck W]

Well why start a separate thread that doesn't have all of the info?

You get the most help if people have all of the details up front, and you can't expect everyone to remember what your situation is. Starting another thread on the same subject that is also missing information isn't productive, IMO.

When I asked in this thread, what had been done to the car previously, you just said your bought it as a non-runner. It was only by chance that I saw your old thread from a month ago that added the BIG detail that the car was also recently manual swapped before you bought it. No mention of whether it actually ran after that either.

Anyway, I'm still banking on a bad ECT sensor/wiring and extra cold weather (Not sure where in Sweden you are located) as the culprit.

[AndreasJJ]

Well why start a separate thread that doesn't have all of the info?

You get the most help if people have all of the details up front, and you can't expect everyone to remember what your situation is. Starting another thread on the same subject that is also missing information isn't productive, IMO.

When I asked in this thread, what had been done to the car previously, you just said your bought it as a non-runner. It was only by chance that I saw your old thread from a month ago that added the BIG detail that the car was also recently manual swapped before you bought it. No mention of whether it actually ran after that either.

Anyway, I'm still banking on a bad ECT sensor/wiring and extra cold weather (Not sure where in Sweden you are located) as the culprit.

.....didn’t mention that becuse it dosen’t matter i found out so i was thinking why mention something that has nothing to do with the problem.but i understand what you mean,i only stated the problems that i have,yes i bought it as a non runner? Thats correct

And yes it ran after the manual swap has been manual for a couple of years

But anyways thanks for the help