hello everyone... im in kind of a tough spot- my friends car died a couple weeks ago, and ive been trying to help her out, but i cant find the problem. i know its getting spark and fuel, and the maf was replaced last fall, so i think it thinks its getting air, but when i tried to run the codes, there is no black box in the engine compartment. it should be right behind the strut tower by the brake master cylinder, but there is nothing there. or does this car not have an onboard diagnostics system? it turns over nice, just wont start. i cleaned the plugs, new cap and rotor, fuel pressure regulator, fuel filter... where do i go from here?
thanks

 

Is there a grey plug there like maybe someone took the diag box?

 

nope, there is nothing... just two bundles of wires that head up toward the front of the car-

 

oh, also... it does backfire a little bit if when im trying to start it and use the gas pedal, then when i let off itll blast quietly.

 

It might not have the Diag.
Maybe the computer went bad. If it has a pink label with the part#'s on it that computer is pretty common to go bad.

 

No "black box" until 1989 (LH2.4). You know for fact you have spark at the plugs and fuel in the rail?

 

yeah i checked the fuel and know there is, plus there is a strong fuel smell coming out of the exhaust, and the wire from the igniter coil was sending strong sparks... and the computer has a orange? (it was almost dark) tag... is there any other things that i should check? also, how do i check if the maf is bad? i tried unplugging it, but it still wouldnt start. on my car if its unplugged, it just wont rev above 2k... but itll still start.

 

Visit www.stepbystepvolvo.com. There's a great diagnosis troubleshooting guide for 740/940s, and some tidbits for the 240.