Here is the story on the volvo...I seen it parked on the street
for almost 6 months and I walked up to the owner to see if he wanted
to sell it and he said sure you can have is for $50.00 clean title.

Him and I tried several things to see if I would start....
changing Ecu, cleaned spark plugs, cleaned fuse holder so on.
I gave him the $50 and I towed it home. I kept turning the car over
and it would start then die after two second or if you tap the gas.
I unpluged the amm and still no start. did each spark plug fire test.
Clean rich spark on all. Replaced the flame trap. Replaced both harness's

I had a person hold the fuel pump jumpers to see if I could hear
the fuel pumps....dont hear anything from neither one. This common?
If one fuel pump dies would the other stop?

As I understand that circuit, if the light across fuse 5 to 7 goes out when you try to start the car the relay is functioning correctly - the pumps are not trying to backfeed through the light as the circuit has been completed through the relay, meaning your test light has lost the ground that it was drawing through the fuel pumps because positive current is now being supplied to them.

That brake booster hose - if I understand what you're saying it's just unhooked from the booster, and open? If so that's causing a pretty major vacuum leak, enough to really mess up your idle. Plug it off & try again.

One other thing to check is that all grounds are secure & clean, particularly the ring terminals that secure under the fuel rail bolts & from firewall to valve cover.

What's the history of the problems here? Was it running before? What fuel system? (I assume since you were replacing the harness it's mid-80s, LH2.2 with the biodegradable insulation.)
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Chris, Dartmouth NS Canada 70 M-B 280SE, 83 245DL, 84 244 turbo, 90 780 turbo, 92 VW Golf