I have been wrestling with my 80 264 for a few weeks now, and I'm about ready to call the auto wreckers and tell them to take the thing away out of sheer frustration.
Quick history: this car was originally equipped with a diesel engine. My parents weren't very smart, and had the engine swapped with a B23A gasoline engine, as they thought a gas engine would be cheaper in the long run. The professional Volvo mechanic who did the swap was an idiot, so I have one seriously jury-rigged engine.
Now the car belongs to me, and after fixing numerous electrical problems, my carmysteriously died and refused to start. The problem turned out to be a melted set of ignition points (yes, you read right, the dummy used points instead of electronic ignition).
So, rather than extend the problem, I went to my local junkyard, pulled a hall-effect distributor and Bosch ignition control module from an 83-model (same year as the engine) and went home to tinker. After an hour of trying to figure out the wiring from my Volvo manual, I pulled out my Porsche 924 manual (they both use the same ignition system) and figured out how the 4 wires and ground needed to be connected, and another hour later I have the most solid spark this car has ever had! Gas milage increased, as did power output!
Now, 1 week later, I still have awesome spark, but now my car refuses to start. The starter turns, the engine cranks, but absolutely will not start. If I have the gas pedal all the way down, the engine may attempt to start, but will sputter and stop as soon as the starter disengages.
I have excellent spark at all plugs, and my air filter is almost new and has no oil in it, and as far as I can tell I am getting plenty of fuel, as I just picked up another used SU carbueretor and rebuilt it, and after installing it I had exactly the same problems.
in a word: HELLLLLPPPPP!!!!

 

That sucks, I think your problem is that little gremlins have gotten inside everything and had babies.

Check EFI fuses (this happened to me, almost took my car to dealership cause was so baffled).

Hope you get it figured out.

 

fuel pump relay. the impulse relay starts it but the second relay does not take over to keep the car running

 

you might need a new ignition control unit. I have a 78 264GL and after I replaced fuel pump, pre pump in tank, fuel filter, checked the spark, which I had plenty of spark. I had a kid come over who is really sharp and he determined that it was the ignition control unit. it conjtrols the amount of fuel that is released into the jets. With out that it won't start. the only problem is that they aren't cheap. I get parts from a friend who work for a garage and I can get them for about half of what the parts houses are charging. They are only made by Bosch. FOr my car the parts houses want arount $400-500 dollars for one. You can occasionally find one that is used but I try to stay away from used parts.</P>


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Good Luck......Moose</P>