Ive changed the wires, plugs, fuel filter, did oil change, air filter, timing, most of the vacuum hoses, and I still have gnarly cold start misfires. After the car reaches op temperature, runs fine but with a slight miss, occasionally Ill feel a flat spot in the power band. I was also checking the fuel pumps while the car was on (was extra tough since I had to take apart the third row seats) and they sound strained, but both of them sound like theyre running so Im kind of stumped.

 

I heard from a buddy of mine, that the 245s had some sort of diaphragm in the fender that helped with cold starts. Any Idea where I should start?

 

i've never seen a 240 turbo, but thats an LH 2 injection system, isn't it ?

it probably has a cold start injector. no idea what this 'diaphragm on the fender' is supposed to be.

 

ps. best way to check your fuel pumps... find the tank pump fuse (its fuse 4 on later ones, but I think fuse 5 on early 80s models), and use a little alligator clip jumper to connect that fuse to the 'clock' fuse, which is always powered. this will power both pumps with the car switched off. you can hear the tank pump easiest at the fuel filler nozzle.if we

 

Cool thanks! Its k-jet Im almost positive. Ill put a pic up though.

Ill try listening through the fuel filler, its just frustrating yknow? every time I turn it over, I have to wait until it reaches op temp before driving.

 

have you checked the engine coolant temperature sensor? if this is a LH car, you can pull the panel on the right side of the passenger footwell, the ECU is behind there, unplug its connector, and use an ohm meter on the appropriate pins. a hot engine should have a fairly low resistance, and a cold one a fairly high resistance (I need to look all the details up), so ideally, do this when the engine is hot, measure it, then wait a few hours for it to cool down and measure it again.

if its actually K-Jet (I thought Volvo stopped importing k-jet cars into the US by 1981), then I'd have to look in the schematics to see where the ECT goes.

 

hmm, parts catalog suggests the B21FT engine in 1984 was K-Jet, huh. is this a US car?

near as I can tell, k-jet has a thermo-switch rather than a ECT, the thermalswitch controls the cold start injector.

k-jet turbos have a 'charge air overpressure switch' that apparently stops the fuel pumps.

but I've never worked on a volvo k-jet, so I'm pretty much drawing a blank here. I think the first step would be to determine if its a fuel or spark problem when its running ragged.