Guys, I posted on this car about 3 mos. ago and you were all able to pinpoint exactly what was wrong with it almost immediately. It was a bad fuel pump relay, which I replaced and it's been pretty good since. I did have to jumper the 4 and 6 fuse about 1/2 doz times since then to start it but for the most part the new relay worked???? The other day, came home, parked it and went out to try to start it next day- nothing-tried jumpering fuses-still nothing.
Now 2 of my 3 bricks are down, I have my 93 940 down and out with same prob.
Any suggestions? I will see if I have spark tomorrow and shoot gas in the intake to try to get some idea. I sure could use some guidance on methodical steps to take after that. I take good care of the 940 w/ 189,000 and this 91 240 w/ 109,000 on it so neglect isnt an issue. They both have had new fuel filters recently and the 240 also has a new fuel regulator. Please advise as my 89 240 w/ 245,000 is going to have to get me thru in the meantime.

If it's a B230 engine, go to www.stepbystepvolvo.com for free guide to 740 no-starts. May help you.

Thanks for all your help guys, turned out to be the #6 fuse metal was detached on one end. New fuse-good to go.

Are the fuses and the holders clean?

When you use a jumper from fuse 4 to fuse 6 are you making the connection on the left side of the fuses? When you do that are the pumps actually running?

If it will run with the jumper in place the problem with it not running when it is removed is associated with either (1)the 12v supply to the relay (via the red wire through the 25 amp fuse), (2)the fuel injection relay, or (3) the ground provided by the ECU to the relay plug.

None of the effected cars are still running the pink label 561 ECU are they? - these were mostly associated with the 89 and 90 model years.

Randy

The first thing is do you have spark? Fuel?

Check engine light? Check for OBD codes and post back.

25 amp fuse near the battery, is it good? Are the connections at the fuse and battery corrosion free and tight?

If the fuel relay is good you should not need to jumper the fuses. Make sure you have a good relay.

Dan

OK. I found that I have no spark. IT IS NOT A FUEL DELIVERY PROBLEM. I put a known good coil in from my '89 and that is not the problem either. What should I check for next? I cannot read the OBD codes as I have no provision for that. Furthermore, for whatever reason there is NO 25 amp fuse for this car. I know this b/c my '89 has one but there is none present on this car...just a junction box. What should I check for next? I am not very electrically inclined, and I do not do well with checking electrical connections. Would swapping any parts out from my '89 to this car help me determine what the problem is? ex. ICU?
thanks

I didn't read to carefully as stated the 25 amp fuse was moved inside for 91. No spark but wet (gas) plugs could be a bad power stage/ ignition amplifier. It could be bad cap, rotor or plug wires also.
Yes you do have the OBD module mounted on the back side of the drivers strut tower.
Check the crank position sensor for bad insulation at the sensor.
Dan

Couple questions guys, I will go to the FAQ's and look for info but also ask questions in case I cant find what I'm looking for.
Do I need some special tool to read OBD codes?
Is the crank position sensor the same as what's called an RPM sensor (just changed this on my 940) cause it woudn't start?
Ignition amplifier/power stage/power amp-?? are these all one in the same and where is it located? I will swap out from 89 if I can locate it.

No, just follow the directions.

http://www.brickboard.com/FAQ/700-900/EngineOBDCodes.htm

Also known as RPM sensor.

Yes one unit located beside the battery mounted on a heat sink to the fender about 3" long with an electrical connector.
Dan

Cannot read OBD codes?
Your 91 should have the fault code box near the left shock tower. Both my 91's (5-speed & auto) have it.
Here is FAQ;
http://www.brickboard.com/FAQ/700-900/EngineOBDCodes.htm

The 91 will not have a fuse in the engine. Instead the fuse in question is #6 inside the car.

Try to check all wires are connected to coil. Cap and plug wires OK?

Could be the power amp. I think you could swap the power amp from the 89 to test.

ICU maybe, but it could be simpler.

I'm sure I'm missing some other things...

Try wiggling the #6 fuse holder while your cranking the engine. I had a similar issue, I found the plug on the back of the blade that holds the #6 fuse was loose and if I wiggled it hard enough, the car would start. I bypassed the fuse with an inline blade style fuse holder with the proper amp fuse in it.