This problem is intermittent and is driving me crazy. My 93 850 normally aspirated with a manual transmission will cut out then immediately back on during acceleration in first and second gear. It seems like you just turned off the key and then turned it back on. It doesn't do this all the time, only periodically. It drops no codes when this happens. Any ideas?

 

Engine hot or cold. Going up a hill? How many miles?

 

Engine warm. uphill, down hill, doesn't matter. 221,750 miles.

 

I have an NA 5speed that did this, and this probably not your problem, but in my case the rear intake cam seal blew completely out. Oil was flowing into my distributor. Once in a while it would get enough oil to drown out the spark just for a second or two. If you don't have the oil running out under the distributor, that is probably not your issue. It is easy to check and fix, though. Easy to get to.

 

Its probably a fuel delivery issue. Pretty sure your car is obdI so you can't pull codes from it anyways. I'd look towards the fuel pump/sending unit.

 

you can pull codes with box under the hood on obdI cars
List of the codes
http://www.matthewsvolvosite.com/read-codes-volvo-850

 

you're right, should rephrase, you can't pull any USEFUL codes from obdI. A fuel delivery problem or pretty much any failure of the engine that isn't related to the emissions system or cant be deduced by the temperature indicator or oil pressure indicator wont cause a check engine light nor code. Also, most obdI systems don't store codes so if the problem is intermittent it will be even more useless.

 

Your problem sound much like a fuel delivery issue.pull up the codes and let us know

 

The diagnostic reader under the hood as shown in the video a few post above is amazing. I stores and retains codes that do not trigger the CEL. It also gives codes a lot more specific than the OBD-2 port.

Quick questions... does the black out require you to loose your oem radio code? That will tell you if you have a total power loss or just some other kind of issue like fuel delivery failure. Fuel pressure failure will not trigger a code like most other problems. Since your car is manual, it will allow recovery of fuel failure since it is basically bump starting the car when in gear.

 

Success is at hand. It finally threw a code for me:2-1-4, on socket 6 of module A. Intermittent RPM sensor signal. Replaced the sensor and it runs like a top again. I'd like to thank everybody for their inputs on my problem.

 

The problem came back the next day. Bummer. Furthur head scratching and trouble shooting is progressing now. Found some corrosion in the connector for the igniting control module. We'll see.

 

I now believe that I have found the culprit for my problem. I have cleaned any corrosion I could find from the ICM connector and removed and replaced the Ignition Control Module. After a couple of days and many in town miles the problem is gone. Even some minor misses noticed during acceleration have gone away. Hope someone else can find this information useful.