Volvo Repair: 86 to 93 240 engine swap, fuse panel, fuel pressure

Question
Hi Phil;
I recently purchased a 1993 engine and put it in my 86 240, every thing fit fine, I used the distributor, intake manifold and injector set-up from my 86. the problem is it will not start, it has spark but no fuel pressure, I suspect the ECU
might be bad, I have jumped the fuel pump at the  fuse panel and activated it but still no go. Is there any problem that you know of with an 86 to 93 swap? it has a 280 000 544 ECU unit in it now I have a spare ECU but it is a 280 000 510, are these units interchangeable? also I have read about the radio supression relay suppling 12v to the injectors, can you tell me where this is located and if this might be the problem?, Any info you can give me would be greatly appriciated.
Thank you for your help...Bill

Answer
Shouldn't be any problem with swap.
You said you energized the fuel pump, did the fuel pump run and was there proper pressure.
If your ECU was working before then that shouldn't be the problem
The relay you are talking about is in the engine compartment by the coolant bottle I believe.