Greetins.

This post outlines my struggles with my 91 744 non turbo auto w/ Regina style FI. Car wouldn't start, plugs were bone dry. Turned out to be the radio suppression relay, a black box an inch or so square mounted on the coolant fill tank passanger side. Had i had my head on, all i would have had to do is swap it with the identical one next to it (which controls the fan i think) and could have figured it out right away. Instead it started replacing the pump (only one on this system) filter, pump relay, etc. for big $$$. Finally figured out it was the RSR, popped it open, resoldered and resealed. runs perfect. One other thing, I discovered a self diagnostics mode or something I've never read about on other post by putting the jumper into plug 2 of the under the hood tester thing and pressing the button for 1 sec, three times with about a second pause between. It will run the injectors, pump relay, RSR, and others. Kinda cool. give it shot. it actully caused my car to run briefly after doing it because before if figured out what was wronge because it fired up the injectors and pumped gas into the intake.

best

 

Welcome to the forum.

The RSR is a fairly common failure.

For a full how-to on the diagnostics:

http://www.matthewsvolvosite.com/cha...c&start=12

The codes may be slightly different as you don't have a turbo but the method is the same. Any codes you can't find post here for help.

 

You can also visit www.stepbystepvolvo.com for the diagnostic guide on 740 no-starts.