Volvo RWD 700 Forum

From Mon Jul 20 00:57 EST 2009...
Could it be the ignition switch?
• Anything is possible, but that would be way down on my list of "known suspects".
Fuse tray?
• Also not too likely, as with the relay rack socket terminals mentioned below.
FPR blue plastic socket?
• Don't understand "blue plastic socket". The Fuel relay should be White, and plugged into a relay rack "socket", as shown in the FAC figure below:


From Mon Jun 29 07:09 EST 2009...
So, to reiterate, if I unplug one of the injectors, plug in the test light, and, it doesn't start AND doesn't light then the ground pulses aren't arriving?
• Correct. Most likely (known) cause would be a failing Crank Position Sensor, which would mean no timing pulses to Rex Ignition CU and thus no spark or "awakening" of the Regina FI ECU.

If the noid light flashes and it doesn't start it is something else.
• Correct, but "something else" would be rare, compared to what I outlined above. The flashing noid light would confirm the CP Sensor, Ignition timing pulses, and FI ECU injector control pulses. That would leave the basic fuel supply to suspect, i.e., Fuel relay, Pump, or something rare like pump wiring or relay rack terminals. I don't see any of those as likely causes of an intermittent problem, when compared to something like the CPS.

Well... one more (infrequent) suspect does come to mind: the ignition coil contacts.
If they weren't making good contact, everything else would work, but the spark plugs would become fuel-soaked after several starting attempts in close succession. The coil can be removed to clean the contact terminals, as shown below:


--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.