My working-almost-fine-as-dandy 1990 Volvo 245 DL Wagon beckoned me to change out the intake manifold gasket because it was time and the idle was rough. So, $11.99 later from parts store I began to start the job but got the itch to remove the fuel injectors and clean them up a bit. In the past I put a rag under the fuel rail to catch the gas under pressure. But, being a willing web surfer, I found several persons advising to relieve pressure by running the car and pulling the fuel pump fuses out and let the car starve itself and shut off, thus relieving the fuel rail of pressure. So, I did that.
Strangely, I pulled fuse 6, the main pump and the Volvo still ran happily. After a moment or two I pulled fuse 4, the primary pump, and the Volvo kept on running. I waited, and waited, then gave up, shut off the key, and did my gasket and injector work. I replaced fuses and tried to start the car. Nothing, nada, crank but no start. No initial 2 seconds of fuel pump. 12 volts to empty fuse 4 (closest) and main pump runs and jumper 12v to empty fuse 4 (furthest) and primary fuel pump runs. Still no start. Here is the weird part. After running fuel pumps with jumper, I remove the tube off of the fuel regulator, fuel side, and I get suction of air instead of spurt of fuel. So, my perfect, almost, 245 DL is now just a sitting bucket of bolts and 2 hours ago I was a sane and happy guy. I should have used my rag under the fuel rail to catch the fuel pressure instead of pulling fuses to try to stall the car. Whata dummy. Fuel pumps now running backwards? Gremlins? Karma hitting me for my bragging about the Volvo yesterday at the gym? Who knows? Any advice on how pulling fuel pump fuses was a colossal mistake? And why? And how to remedy it?
Thanks.
Bejinge

 

As my moniker above says, I am a junior member. I just proved it. Going back into the garage, I loosened the fuel rail "in" fitting and indeed fuel was there. The "suction" I spoke of was on the return line after the fuel regulator. So, my question remains as to why pulling fuses 4 and 6 did not shut down the car, and why pulling those fuses caused my no start issue and no initial pump on with key. But, I was wrong about the fuel pumps not able to pump correctly.

 

First rule about old Volvo ownership and maintenance is "do less"! Or, if it ain't broke, you know the rest...
As far as the pulling fuses, stopping the fuel pumps etc. to relieve pressure, total nonsense. Crack the line open with a rag over it, a little fuel squirts out, no big deal. You were right not listening to the poindexters' bs on the internet at first...

 

All know the routine now. If you have fuel check for spark.

 

I spent all day without giving up and reading everything on this forum and everything I could find in the world about Volvos and starting problems.
To review: All was well until I removed fuel rail to check injectors and install new intake manifold gasket to improve my idle. (Gasket was indeed in poor shape.)
I blamed my no-start situation after reassembly on advice I received to remove fuel fuses to starve fuel and take pressure off of rail. This was unnecessary and was not the cause of my problems as it turns out.
I followed the troubleshooting advice given here in this forum.
But I kept coming back to: I had fuel if I jumpered pumps, good spark to plugs, no injector operation, no pre-pump run when KOEO, no diagnostic LED on OBD-1 when KOEO, and no check engine light on KOEO.
So, PCM, right?

I started on a check list for the PCM. I found a website in Australia that told me what to find under each pin of PCM plug. While reading I came to pin 20 on the PCM plug and lo and behold, the answer hit me between the eyes. GROUND on the MANIFOLD. I ran into the garage fully expecting what I found, picture below. I failed to reinstall my ground wire for the PCM!!

Success. The 245 DL is running like the old sewing machine it wanted to be. And the rattle and shake at idle is gone with my new gasket ( FelPro )installed to seal out my small air leaks.

thanks for forum. It helped to write it all down.
Sorry for poor picture. Here is link: https://ozvolvo.org/discussion/7351/240-no-start/p4
What the picture shows is "pin 20, Signal Ground terminal on intake manifold."