Brian Mee hit the nail on the head for me when he suggested the moral of this story "always to have an additional 240 around." That really sums up my family's automotive thinking over the past decade and a half. Not so much to have swap-ready parts, but to have in-depth experience in a narrow field.

Yes, it was warm summer day almost 15 years ago a gentleman pushing a baby stroller past my driveway stopped, seeing multiple 240s with me under one, to ask me if I knew I shared a hobby with General Colin C. Powell. I questioned, thinking, "oh, you mean he owns Volvos?" and he introduced himself (and I fail to remember the exact relation) as he surprised me to explain the General worked on them.

Years later when I read General Powell's autobiography, I learned he enjoyed the hobby the same way I do -- learning and understanding every part of the automobile. And when the time seems to slip away for keeping up with 8 old 240s I feel encouraged to read a busy future Secretary of State found the time to provide his kids with safe cars and eventually take 30 of his 122's from rescues to daily drivers.

The reason for my post was to capture a logical troubleshooting approach while it was still fresh in mind. As joekidd points out it was concise. A little too concise. Some email questions "why did you ..." make it clear to me there were assumptions I made not stated. And there is this implication I've found the root cause, as in solved the problem for certain. Not so.

Because RolandP compliments me on troubleshooting procedure with saving a copy, I feel compelled to explain my steps in more detail. Well, I figure if you've made it this far reading, you are specially tolerant of wordiness and detail, as much as I love the man of few words diagnoses.

Also, because I was not working in a heated garage on a lazy Sunday afternoon, I took some shortcuts. We all know the danger in skipping the steps in a logical procedure.

So here it is, explained: EZ-116K Ignition Amplifier Diagnostics

Found it cranks strong but not a hint of fire.

Not said: Has recent timing belt, and I do well recognize the sound of an engine cranking without the compression of all cylinders offering resistance. One should not assume as much as I did. Check under the oil cap and make sure the cam is turning.

Left the key on, popped the hood, and checked the OBD. Had a 232 on fuel side, 111 on ignition.

Beware red herring: The step here should be one to determine whether spark or fuel is missing. Problem is, I have the habit of checking OBD first thing. Also, I bring a suspicion along that this 91 is repeating an old trouble solved by replacing fuse 6 (peculiar to 91-93) with a copper fuse, and I know if that was the present problem, there would be no codes or a 111 on fuel. The 232 is an emissions code which, by itself, never causes a crank, no start.

Took out a test light, rolled back the AMM boot, and saw good battery on the orange lead.

Here is a very valuable trick. Doing this verifies the fuel injection's power system where it is so often vulnerable -- along the red lead fuse on the fender in 83-90, at fuse 6 on the inside fuse panel 91-93, and the battery terminal-mounted PAL fuse on late production 93. Just be aware Volvo changed the wire color from orange to red/black when the fuel rails began to sport Schrader valves in 92.

Finding voltage here gives me confidence in that fuse wiring and the fuel injection relay above the passenger's feet. And with the key on, the voltage is measured with a load on it, so even a sensitive multimeter will give you the truth.

Checked at the coil, also good battery.

We are checking electrical power because poor electrical connections comprise an overwhelming number of reasons for any suddenly dead 240. Look at the terminals on a 240's coil. Out in the weather. I don't want to wiggle them -- not yet. I want to find out exactly where the bit of oxide is that is keeping this car from starting. So with a test light, I probe the coil's terminal 15 right at the threaded stud. If the car was blocking traffic, well maybe then wiggling the crusty terminals is a good expedient.

Got out the remote start switch (jumper between test socket and battery positive) and cranked with test light connected across coil (term 1 to 15)...

Having quickly verified the spark and fuel systems both have a power supply, this is a quick and fairly universal way to start on verifying spark. The coil has to be charged and discharged to make spark. With a small lamp connected in parallel to the coil primary, we can see whether the timing signal, ignition computer, and ignition amplifier are performing the function a simple pair of points used to in our older cars. If the light flashes when the engine is cranked, all that is then needed is to check the coil high voltage terminal gets its spark to each of the plugs.

Double checked by unplugging the coil wire, then connecting a jumper lead from ground to a scratch awl with a rubber handle held near the open coil high tension terminal

Double checked indeed. Without the flashing light above, this step is redundant. Habit again, I admit. Without a test light handy, checking for spark at the coil goes a long way toward eliminating those "breaker points" components from suspicion, but because the distributor rotor, cap, wires and plugs are also needed for effective spark, the verification is not complete.


Suspect CPS. Gave its lead a shake and repeated cranking.

Here was another assumption of mine. It seemed like many years had passed since I changed the CPS on this car, but I do remember reaching it lying on a piece of plywood over the motor. Before I did it, shaking the old one would get it to work for a bit. Habits die hard.

Got out the DMM. Checked resistance of CPS at its plug. 160 ohms.

Experience helps here, but this check is not really conclusive. I've seen this test expose a bad one as well as not. 160 ohms is an acceptable number, I knew without consulting the book, having replaced intermittent failing sensors when catching their windings at 500-900 ohms upward to several hundred thousand. Just remember when you measure this, the temperature of the wire affects the reading a lot more than you might imagine, when you compare it to the nominal quoted 250 ohms. To convict one, you are looking for an open circuit, or one that is being conducted through corrosion.


I see 300mV DC on input gray lead referred to the battery post. Cranking causes the display to bounce around 1 to 2V

Again, not really conclusive. The "300mV" is going to vary depending on the integrity of a lot of ground connections and paths. Toying with this later, in a warm garage, I found I could reduce that base voltage to 25mV (key on, lights on) by cracking and retightening the body ground from the battery and the fuel rail grounds for the engine management systems. But the meter pretty consistently bounced around a couple of volts catching the pulses from the EZK ignition computer while cranking, so this may not have been conclusive for input to the power stage, but I found it a strong enough indication to say "has power and input, but no output."

Swapped in the ignition amplifier from the wagon

Ok, I swapped the part and the car starts and runs, poorly at first, as it cleared the fuel from the cylinders. It was getting late in my lunch hour and I now needed a ride home. This is where I cut corners. I did so, because when I pulled the module I saw the connector was filled with connector grease.

After work tonight, I'll return with a spare power stage for the wagon.

With the part swap, I jumped over an important step by not trying the suspect part in the donor car -- or even just putting it back in temporarily, just to assure myself the act of swapping didn't just clean a dirty connection.

The weather and circumstances kept me from fetching the wagon for a day, and when I did, I just popped in a junkyard power stage and drove it home. Weekend arrived, and with it the time to examine the old power stage.

The unit checked good on the bench (testing is a story for another thread) and in the wagon. I was hoping to have a confirmed dead power stage for a post mortem, but instead all indications are the original problem was just a poor connection in its plug. I am running the suspected unit in the wagon now, and even this morning at -3F it starts right up and runs. For now I'll just leave it dangling next to the battery and keep a spare in the glove box.

So once again, the short cut was a poor choice. The expedient of part swapping comes with an obligation to repeat the swap (most critically with electrical parts) to confirm the "dead" part is indeed dead. Right now I think having a spare 240 handy circumvented what might have been a "reseated power stage connector" solution.

--
Art Benstein near Baltimore

I went to buy some camouflage trousers the other day but I couldn't find any.