PLEASE, someone help me find some really good wiring diagrams for the 700 series. Especially the fuel system wiring. I need to know what the wires do, and where they go. Need to figure out what makes my 740 prime, and pump. Just swapped a new pump in, and need to test before I look further in to the system. Want this wagon to run now! Such a sweet complete 5 spd turbo wagon barn find, and I don't want to just give up yet. Thanks for the help.

And yes I previously posted this in the wrong place

 

ok, turbo. what year? there's LH2.2 on the earlier ones and LH2.4 on the later ones, and some differences in wiring. one quick way to tell its LH 2.4, there's a diagnostic block on the left strut tower, its a black rectangular thing with a plastic cover, 8(?) numbered holes under trhe cover, and a little jumper wire.

the short version is, when you turn on the ignition, the ECU should tell the fuel pumps (there's two) to come on for about a second, then off again, and when the car turns over due to being started, they come back on. they get their power through the fuel pump relay, which is part of the fuel injection relay on a LH2.4 car (I don't have the wiring diagrams for a LH2.2 740T). said relay is in the main relay panel thats behind the ashtray, in relay position E on the LH2.4 cars.

the ECU won't know the engine is turning over if the crank position sensor (or its wiring) has failed, so after taht first spurt of fuel pump, you'll get no more.

the best (and really ONLY good) wiring diagram for a Volvo is the 'green book' for your year/model car. I have the one for a 1992 740/940. You also can get a DVD from VCOA that has the diagrams for ALL years of a given family (2xx, 7xx, 9xx series each have a disk), these diagrams are in the form of copy protected PDF files that have to be viewed with a special program, so you can't share them. these dissk are WELL worth the $65.

mmm, appears they are out of stock of all but the 240 and 850 series now
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I'm sorry, it's a 1988 745t. I have found that at crank there is power at the pump connected, but there not the initial prime. I have $500 into this gem, and EVERYTHING works, except for it not starting. And yes it does have spark, tested at every spark plug. I'm trying to focus on the wiring because there might have been a mouse chewing on wires issue. Thanks for the pointers.