Fuel pump issues.....
+B should be +12V anytime the ignition is on. It is controlled through the efi main relay. It is fused through the EFI fuse. If it isn't 12V with ignition on then there is some issue.
Yeah I got 0 Volts on B+
Did you remove the fuse and check each one with a multimeter?
Yes
(I have been caught out before with a fuse which looked fine but was broken).
If that checks ok. Then you need to check the wiring to the efi main relay. There are four pins, (assuming same colour codes as 93 ls400) there will be a black yellow wire which should have 12V at all times, black-red which should have 12V with ignition on, white-black thats earthed and black-orange that is 12V with ignition on.
So should it be that these wires are the same colors at the ECM? I check which plug and udate so everyone else knows.
The black-orange wire is the output of the ECU which turns on the EFI main relay, if its not 12V with ignition on then make sure the IGSW pin on the ECU is at 12V when the ignition is on. If the IGSW pin is 12V and the M-REL (black-orange) is not 12V then it would suggest to me the ECU isn't wired correctly or is faulty.
Definitely will check this one....
Is this a conversion you are working on? Or the original engine/car. Has it been running in the car?
This is not a Conversion but in the Original Car that has been sitting for about 2.5 years, just had a new fuel pump installed a couple of months ago. Also the Guy who worked on it about 3 months ago had to Jumper from FP to B+ to get it to run. So after that event, and sitting up for 3 months, It does Nothing. The pump will run though but only if I put 12v on it directly at the pump terminals behind the seat.
I took the ECM out to check visually for problems and found a couple of Leaky caps:
![DSC08691.jpg DSC08691.jpg](https://www.lextreme.com/forums/data/attachments/17/17319-871afe8c9502c77ea1f689e8eca4f610.jpg?hash=hxr-jJUCx3)
The world of ECM repair is seems to appear as a "Secret" as is the "ABS" module the Volvo world...but I have more time than money to easter egg parts. Junk yards are High as H3LL here!
Not sure what these control but I will replace them anyway.
Not sure what Pin or Port #
M-REL is as the Unit's ports are 34P 22P 16P and 28P and apparently are the number of pins for each connector.
What Connector # has M-REL, B+?...I guess that will be the same as the wire colors you stated if they go the complete path without a a color change eh?.. I am collecting this info and creating a log so when I write this up the next guy should be able to breeze thru. My guess in my case is a Dead ECM But the adventure continues.
Thanks MX. Your's and Anyone else's ideas are Welcomed.