Long time member, researcher, first time poster. I have a 1994 Volvo 940, 235K miles on it. B30, non turbo. I had a radiator leak that I was trying to buy some time on since I had to order the correct one. Been keeping coolant and water in it and it never ran hot. I used some Blue Devil radiator sealant in the mean time, and had no issue. While I was on my way to my destination today, heard a loud pop (once), and car shut off. I waited about 2-3 minutes and it started right back up again, and I was able to drive to my destination 5 miles away. Parked, took care of my business, came back out about 2 hours later. Car started, got in reverse, then cut off. Now it won't start at all. Tries to crank but just won't get going. Checked timing belt, it's just fine. No breaks, wears, nothing. Did the timing jump, or am I looking at one thing much worse? Sorry for the long post, just trying to be as detailed as possible.

 

So the car never overheated? Is the coolant all there? Is there any signs of coolant in the oil, milky beige slime? Or it could be something unrelated to the cooling system, hard to say without hands on... Jumped timing happens rarely, it's often blamed, in your case the "pop", well, it may indicate something like that but if the belt looks good, hard to say...

 

Well... Like I said, I had a radiator leak, and used some Blue Devil. I used water to top it off, filled it up. No overheating though. The tank is empty, but that's because of the leak in the radiator. Its not a heavy leak, but it's not a slow leak either.

 

After the car has been sitting for a while can you turn the ignition on and hear the fuel pump run for a couple seconds ??

Have you checked for spark ??

Have you checked all the fuses ??