So my 1975 240 just won't get running. I have narrowed the issue to the fact that the cold start valve doesn't seem to be getting any power to it - the mysterious black cable (with a black and brown wire inside) goes off into a maze of wires. I feel like I've rewired the whole car at this point, but can't seem to get it going. Any tips? Anyone know where the problem might be -or- know a way I can just bypass the whole mess? I am not a mechanic by any means so use simple terms - have had a hard time getting a mechanic who will a) work on this beast and b) show up, so have resorted to doing it myself.

Help please! Thank you!!

 

..."won't get running"?
Is that like it won't start?
Why are you so sure it's the cold start valve?
What do you mean by "rewired the car"? That is a pretty loaded statement, and begs all kinds of further questions especially since you are "not a mechanic by any means"...

 

Yes it won't start. By rewired the car I mean I traced each wire having anything to do with the cold start valve back to the starter. I am not a mechanic but I was taught home electrical wiring by my father (general contractor) from birth so I feel okay with electrical work, but I seem to not be getting this one right.

The cold start valve is not putting anything through. There is fuel pressure to the valve, but none coming out, and spraying starter fluid into the intake starts the car right up.

 

Are the fuel pumps OK? Relay? I am not into these older cars so much but I believe that the cold start valve won't cause a persistent "no start", rather a difficult, stumbly start...
See Volvotips, for some detailed help with diagrams, etc.

 

that car has one fuel pump. it is right after the driver rear tire.
I dont think the cold start is not the problem.

check power to the pump, and fuse. then check fuel pressure.

you can check to make sure its getting fuel by: undo the injector hold down bolts, and point them away from the car. then remove plastic hose on the intake so the fuel plunger is exposed. put the key to position 2 and pull up on the plunger carefully, you show see the injectors spray.

that is basically all there is to the fuel system on that car.

if that is all fine, then move to the ignition system.

 

The cold start injector runs for 12 sec at -4F. and decreases run time until it ceases operation at 95F.
Undo the cold start injector and point into a container and then run the starter motor from the key. If there is no fuel expelled and 12V appears at the socket pins, then the cold start injector is bad. If there is no voltage at the plug,then either the wiring is bad or the thermal time switch is bad.

Testing the thermal time switch depends on an operable cold start injector. lol.

(links visible in this post to those not logged in are from the website, not me)

 

This page in particular is a good read:
K-Jet In Detail | K-Jet.org

The site isn't half bad either (check out the "greenbooks" link).