I bought this 1989 VOLVO 740 GL 2 weeks ago for my daughter. It ran great for one day. I am an auto tech. so I do know some things about cars. The car starts fine and will run for 2 miles and then loose power. It never stalls just wont move. If I shut it off and imediatly restart it, it will run fine again for another 2 miles and so on and so on. I checked fuel pressure and found a bad in tank pump. I replaced it and I still have the same problem. I replaced the amm and the ecu and it still does the same thing. I replaced the o2 sensor and it still does the same thing. I checked to see if the o2 sensor is working with a dvom and yes it works fine. I replaced the fuel pressure regulator and the power module for the ignition system and it still does the same thing. I cleaned the throttle body and checked and adjusted the throttle switch and it still does the same thing. Oh, I also of course did the cap, rotor and plugs. PLEASE HELP ME!! I AM OUT OF MONEY AND PATIENCE. The only thing I see is that when it runs fine, with a timing light hooked up on accel. the timing will retard 1 or 2 degrees before it advances. If I check it when the problem is occuring it will retard 6 or 8 degrees before it tries to advance. This led me to replace the knock sensor but guess what. I still have the same problem. My questions is: What can cause this? The crank sensor? The EZK? Should I replace the hub caps ?? PLEASE HELP ME, MY CAR IS BROKE AND I AM BROKE. THANKS,,MARC...
Thanks to everybody that replied to this original post. The problem is solved. There is nothing worse then getting a new part that does not work. One of the things I replaced way at the beginning was the knock sensor. I looked every other place and spent lots of extra time and money because of a defective new part. And its just a knock sensor, what could be bad about it. The computor thought it was ok, it did not set a code but everything led me back to it. I went to the junk yard and bought one for $5.00 and the car runs great. I want to shoot myself, the car, the dealership that wont give me my money back and Volvo. Oh well, My daughter is on the road and happy. Now I can go back to work on my PV544,, Thanks again,, Marc..