Lately I've been experiencing the occasional hard start with my 1992 Volvo 240. It would crank and crank and crank, only to finally fire up after about 5 seconds or more of cranking. The problem has been very intermittent, and not really dependent on any factors I can see. Once the car is started, there are no drivability issues whatsoever.

I popped the hood to take a look around, and this is what I found after unclipping this wire harness from the firewall:






This harness seems to disappear under the intake, and possibly into the main harness, so I'm not yet able to locate what exactly it goes to. After reading around, it appears Volvo 240's are notorious for deterioration of wiring insulation, however, I believe I read it should have been corrected by the time my 1992 Volvo was manufactured.

Here is a close up of the connector:




And here is the car in question, at 176,000 miles!:


So I guess my question is what is this deteriorated wiring go to? And what is the best way to fix it?

Any help is greatly appreciated. Thanks!

 

FOUND IT!

Engine Speed Sensor/Impulse Sensor and although it might be an a bit of an ackward spot, it's definitely doable! And yet it's only around $40!

 

Welcome to the forum.

Yeah, a frayed crank sensor will give you occasional no starts, obviously .

Nice 240 BTW, looks super clean from that one side.

Any other questions you have that we could answer this time?

 

Thanks! The car is actually pretty clean. The only body issue is a small crinkle on the passenger rear side where the bumper wraps around. I accidentally slid into a frozen snow bank and push it in. I was able to get it fixed, but the paint cracked, and it would could too much to repaint it properly, so I just had them touch it up. Other than that, I love the car! I'm looking to add a set of fog/driving lights, and I've found lots of great examples here on the forum. Looking forward to becoming more involved here. Thanks!

 

I cannot over-emphasize how devious and frustrating a crank sensor problems can be.
My 740 was intermittently stalling at 55 mph plus on the highway. The engine would suddenly cut out; I would bring the car to a stop on the shoulder and restart. After a few seconds the engine would restart and run fine. At first the problem occurred once every few months. Then once a month, once a week, and finally several times a day.
Because I had a Saab that died on the Interstate for the same reason and left me stranded miles from home. I bypassed the expensive diagnosis process and insisted my mechanic install (a) a new crank sensor (b) a new fuel pump relay and (c) a new "radio interference relay” which is really a fuel injector relay. Worth every cent. The problem disappeared. I took out the new fuel injector relay and swapped it with the old one. Works fine. I now have a spare. Also saved the fuel pump relay and crank sensor as emergency spares.
An intermittent crank sensor can test good on the shop and leave you dead on the highway.
Volvo relays, especially fuel pump relays, notoriously overheat and cause intermittent problems. The fuel injector relay can go flaky and cause the engine to flood, imitating a whole bunch of other expensive problems. Those above items are the holy trinity of Volvo survival.