no spark no start
 

First of all I would like to thank tech, boxpin, and bobec for all their help in a very perplexing no spark no start problem. Second of all I would like to apologize for not posting the progress of this problem for the rest to read and learn from. It has taken over 2 months for me and the above members to track down. I can not tell you how demoralizing and frustrating it was, but in the end a very simple fix. Now for the meat of the story.

I have a 1994 850 turbo, that I got for 500.00 or less (I can not remember) with a burnt valve. I took the engine out to fix the head issues, clean, and get to stage zero. The car has over 300,000 miles on it, but had been surprisingly well maintained. I got everything cleaned and back to stage zero, and the engine & transmission back in the car. After putting the rest of the car together, it was time to start her. I turned the key and she spun over. After doing this for several minutes (car had been apart for over a year) I figured something was wrong. I had fuel to the rail, I had power, I had no spark. What could it be? I had new cap, rotor, plugs, and wires.

I started with the obvious things, cam sensor, crank/rpm sensor, coil, TPS, grounds, battery, fuel relay, PNP, and engine coolant sensor. All checked out good, and I even swapped out good used ones to make sure. Still digging deeper and deeper, I started checking everything. Following the above members advice, but still came up with no spark.

After exhausting all of the information and experience I could get a hold of, I decided it was time to start pulling out the wiring harness. Starting at the battery I pulled apart and uncovered the harness. Finding nothing burnt, melted, or corroded I was totally bummed. The only thing left was the ECU's. The car started and ran before I took it apart, so I was kind of sure it was not them. I had only taken them out after the rebuild, because I had read someplace, that they may need to be reset in their sockets. I had a no spark before I did this.

As I took out the ECU's and the box they sat in the only thing that I saw thus far that represented a problem appeared.On the ECU connector for the engine, 3 of the sockets had been crushed/smashed closed and pushed down in the connector. Fixing the sockets and putting the ECU's back in I got my spark. I can not believe all the trouble I had gone through to get to this point.

Some of you may have started here, or looked here earlier, but all things being Volvo, this was the last thing my trouble shooting was pointing too. I know this is a long post, but my search was longer. At this point in time, I know I am more knowledgeable at how my car works, and is suppose to work. In closing it is always something right in front of your face, you just got to take your time and look good.

I hope this post will save someone from spending all the time and head ache's I went through, in solving their no spark problem.

Glad you got it!!