2000 S80 2.9 Intermittent crank no start

[JBaldy]

Hello all, I am new to the Volvo world having just picked up a super low mileage (26k) near mint condition 2000 S80 2.9. Its a southern car (no rust), garage kept and rarely used, especially over the last 15 years. When I went to look at it it was hard to start but after much cranking it did start and run fine. We attributed its reluctance to start to stale fuel from it sitting so long. Took it for a test drive with no issues (except clunking strut mounts) or warning lights. It fired right up the next day when I went to pick it up and trailer it home (wasn't going to take a chance on the 15 year old Michelins even though they look brand new).

Since then it has been intermittently hard to start. Siphoned a good 10 gallons of old fuel out of the tank and dumped in about 5 gallons of fresh gas and a bottle of Sea Foam. Hoped that would take care of it but no such luck. Sometimes it will start right up no problem, other times it will crank and crank but not fire. Eventually after several tries it will start and run a little rough for a few seconds then smooth out and run fine.

When it doesn't fire right up and I keep cranking, the tach will jump all over, the check engine light will flash, all kinds of error messages will pop up, I think I hear the fuel pump turning on and off, the starter will cut in and out, ABS will flash, etc. Not sure if all this is the cause of the no start or the result of continual cranking when it doesn't fire right up. When it does start, all the error messages and flashing lights are gone. There are no codes stored (except the siren module, fuse has been pulled). Everything in the car works, door locks, windows, sunroof, radio, A/C, cabin lights, headlights, etc.

Its almost like the ECM is losing power on and off while cranking. I will need to pay closer attention to the sequence of events when it doesn't start right up. I'm going to pick up a fuel pressure gauge and make sure fuel pressure is adequate. Hoping its not the computer but if anybody has any input, be glad to hear it. I plan on replacing the strut mounts, timing belt, serp belt, tires and misc. other stuff. Thanks

[JBaldy]

So, I removed the Bosch ECM and opened it up and there appears to be a failed component on the board. The damage appears minor and is confined to a small area around what appears to be a resistor. Looks like the resistor might have went bad and leaked black stuff around it on the board, if that is even possible. Don't know if that's the cause of or the result of the issue I'm having. Either way I think this board needs to be repaired before I can go any further. Is Xemodex worth the premium they charge over other automotive ecm repair outfits such as SIA? Thanks

[Cees Klumper]

I had a failed capacitor on an ECM recently and just replaced it myself, cost me less than $3 as I recall. Worth a try?

[JBaldy]

Update: Sent the ecm to SIA for repair and am happy to say that for less than 175 bucks the car starts right up every time. I was too chicken to attempt the repair myself and took a gamble on SIA. I purchased the repair on ebay for quite a bit less than list price. Needless to say I am extremely pleased.

While I was waiting for the ecm I went ahead and did the timing belt, tensioner and idler. Also replaced the serpentine belt, upper strut mounts and bearings. I was getting a passenger door open message and that door wouldn't stay locked so I removed the door lock module, took it all apart (it didn't want to come apart) lubed up the internals, put it all back together and much to my surprise, it works. I'm sure it was the little micro switches in there that were sticking but they wouldn't come apart. Hopefully it will continue to work.

Made several small repairs to the center console mechanisms for the cup holders and to the lid itself. Order new gaiters for the E brake and shifter on ebay for 45 bucks. Trying to get the right cabin filter from rockauto has been a little frustrating but I think I've got it sorted. Apparently I have the 1st version.

Removed the padded A pillar trim that was wrinkled and looked bad. I peeled back the fabric, brushed off the deteriorated padding and re glued with some spray adhesive and they look like new. No parts required.

By far the biggest expense of the project will be new tires. Hate to spend the money but I hate cheap tires even more. Looking for a deal on quality tires but so far no luck.

[Cees Klumper]

Congratulations on the ECM fix, good diagnosing on your part. And thanks for reporting back, always good to learn what the fix was to these oftentimes elusive symptoms. Good tires make all the difference and these days last a long time, so I wouldn't feel too bad about that one. Think of all the money you saved by doing all the repairs and maintenance yourself!