Got an 86 240 b230f stranded in the parking lot at work. About a week ago it had a hard time starting. Few days later it was having an even harder time starting. I pulled off the lead from the ignition coil to the distributor cap and it started up. Later that day it was stuck again, plugging/unplugging the big lead didn't help so I cleaned and reconnected the wires to the ignition coil and it worked. But today nothing would get it going.

Today I cleaned and replaced fuses in the panel. Checked the 25 amp blade fuse. Jiggled and cleaned any other connections I could find.

About 2 weeks ago I replaced the distributor cap and rotor, timing belt, tensioner, and oil seals.

About 2 months ago some wires shorted out to the starter and I replaced those.

About 6 months ago I replaced the fuel pumps and filters, MAF, spark plugs.

Plug wires and battery are probably 2ish years old.

I started taking stuff apart to get at the blower motor and it's possible I disturbed something doing that, but this started before that.

Seems like something in that general ignition coil area is doing it I'm just not sure what. Heard the coil is pretty bullet proof, and given the whole electrical fire situation a few months back I'm inclined to think it's bad wiring. Not really sure where these wires go though or how to test the coil. Only thing suspect about the coil to me is there's a bit of a chip/Crack where that big lead attaches.

Is there an easy way to test for spark? Hard to hold a plug and turn the key at the same time.

Once it's started it runs fine. Not really sure what to make of this. Any tips?

EZ

 

Ive been inquiring about this as well recently

Testing the coil is pretty easy if you have a multi meter

remove all leads form the coil

Primary coil test: check terminals -1 and +15 for resistance (0.6-1.0 ohms)
Secondary coil test: check either terminal -1 or +15 to the "high tension terminal" (where the plug wire goes) we should see (6.5-9.0 Kilohm's)

Since multi meters have a hard time reading half an ohm the primary coil test may be negligible but the reading of 6,000+ ohms should be very consistent.

Next get one of theses AutoCraft Ignition Tester AC664: Advance Auto Parts

If you have spark your coil is "good" or at least presumably good

(note these tests are performed at ambient temperature as higher temps increase resistance)
If your ignition coil is good, use the tester to check each of the spark plug wires, 2 years is kinda old depending on how much you drive

 

are you sure its a spark problem, and not a fuel delivery problem? engine needs compression, fuel, and spark to run, all timed correctly. the spark and ignition timing source on a 86 is a hall sensor in the distributor. if the ECU doesn't see timing pulses, it won't even try to turn the fuel pumps on.

 

I think you were right about the hall sensor. Coil seemed to check out with the multimeter, I didn't have a timing light so I spritzed a little gas down a spark plug hole and that fired off. Plugs looked kind of lean.

Hall sensor seemed to check out on the multimeter, but that little plastic bit has been broken as long as I've had the car. I tried to just kind of make sure there were solid connections and got it sitting where I thought it should and the car fired up, was able to drive home.

 

the little plastic insulator is a replacable piece. the one for our 87 is volvo PN 1389492 which is a $4 part, but probably a dealer special order these days. however, my old parts catalog suggests there could be one of 2 different distributors, and doesn't explain this, so the other one probably uses a different part.

 

Looks similar enough, for $4 I'll give it a try at least. Might look for a junkyard distributor to rebuild in the long term. Replacing the sensor looks like a pain to do on the vehicle

 

note that junkyard distributor will likely have to be from a ~ 85 to 88 240. 89+ with LH 2.4 use a crank position sensor so there's no hall sensor in the distributor, and 740's mostly have a camshaft distributor at the back of the head, so that won't work either.

btw, I'm not sure about the 1985 part for the start date, thats about when LH2.2 stabilized, so I'm assuming they are compatible. I *know* 87 and 88 are basically identical electrically, and 86 aren't much different.