I have a no-start problem on an 88 240. Some of the things I'm suspecting are the coil & ICU.

Do coils fail often? I have weak spark, but measure 12.3 Volts at term 15 which drops to 10.3 Volts at cranking. The volvo dealer doesn't stock coils, he suggested the ICU may be the culpret.

For the ICU I assume I need one from model years 1985-1988; B230F engine with Volvo/Chrysler ignition (p/n 3517641 on mine).
Any way for me to check mine?
I haven't been able to backprobe the wires at the connector. Can't get a probe in there. I can get a used one for $150. The parts place told me I just need new pins for the cable. Bentley suggests replace the cable that connector gets destroyed doing R & R. Is this true?

Thanks for the help.

Mike
1988 245 217K usually running!

Several months ago I bought a 1988 sedan as a "project" fixer-upper car. As I was driving it home I heard something short out. The car just died. I bought all kinds of replacement parts (distributor (hall sensor), ecu, icu and a few other odds and ends.) The pumps would not run.

After I got all of the parts I started trouble shooting (bad idea). Come to find out there was a screw that fell out where the 25amp fuse is located on that block causing the coil to short out. The Hall sensor, ecu and icu were all unharmed. (Multi Meters work wonders).

Got the coil from Groton. Put a screw in to hold that bar in place. Everthing started right up. I now have a bunch of spare parts in my garage.

Read the FAQ and start with the simple things. Check all connections. Remove the coil and test it. Manually engage the pumps (fuse panel) to make sure they both work.

Good Luck.

Todd :-)
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1990 245 Wagon - 187000 miles; 1988 244 Sedan - 123000 miles

Is there fuel on the no-start? ie. are the plugs getting wet?

If not try forcing the pumps to run, with a jumper from fuse 6 (left side) to fuse 4 (left side).

If it fires, the weak spark is secondary (no pun intended) and the jumper bypassed a fuel problem.

In the 14 years or so that I've known 240s, I havent seen (or heard of) a bad V/C ICU or Coil. Not to say they can't happen, but I'd explore other—more common—things first.

Then, looking back at your earlier post, I see 2 unaddressed comments:

1 - Would a weak spark cause the system to not deliver fuel? I don't think so. If you can see even a "weak" spark, I think the ICU will give the "OK signal" to the LH ECU.

2 - My next step will be to try starting with pumps jumpered. I was waiting to hear the results of that. Which is why I suggested it here.
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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

Bruce,

Thanks for weighing in. Your were instrumental in helping me get the car going the first time I went through all of this (last January).

I did try starting with just the main fuel pump jumpered (I didn't try with both pumps). No start. Then I changed out the spark plugs for new NGK plugs & it started right up.

However, I still believe there is some type of problem lurking behind the scene. The car starts & runs but I can't help but think it is just barely functional. In other words something like fouled plugs is enough to keep it from running. Here are some observations I made:
When checking for spark, it was a new unused NGK plug I put in the cable.
I switched rotors with the old one (I keep both a rotor & cap in the trunk - you never know). It's odd, but I measured the distance from the center of the rotor (as indicated by the wear spot) to the contact edge; one measures 1.03", the other about .97". After the new plugs I confirmed they both work. I went ahead and put the old one with the longer measurement in figuring it may make better contact.
The old plugs were Bosch Platinum plugs with about 35K miles. They look dried out, somewhat brownish in color. They did have a strong scent of gasoline.

So my question is, what type of problem would cause the plugs to foul?

I add about 1/2 quart of oil for every 3K miles between oil changes. However I was using 10W-40 and plan to use something heavier. The car has 217K miles so someone suggested a heavier oil will work better.

Anything else I should check for?

Thanks again for all the advise. I rarely have anyone else work on the car partly because I'm Scottish, but also because I don't trust them. I've learned a lot through all the troubleshooting!

Mike

the problem causing the plugs to foul is the plugs. bosch platinums are too cold for the engine, and many others, and will foul and cause no or poor starts. i'd go for just a cap and rotor-bosch only, wires-oe or bougicord only, no bosch, and either bosch or ngk plugs. i've fixed a bunch of poor running cars by using the right plug, not what's on sale. as far as your other concerns, the coil or icu can fail, the coil more often, BUT, it's rare for either. cross that bridge when you have to. good luck, chuck.

Mike,

It seems like you're doing all the right things, but to go with the new plugs, I'd spring for Bougicord wires, plus Bosch cap & rotor, especially if those items are of unknown age.

And I'm not sure the platinums were necessarily fouled. The gas odor may be due to lack of driving. And the color sounds pretty normal.

You might try for a JY coil, if plugs, wires, etc. don't help much. Most places will let you return it if it doesn't do what you want.

Bruce

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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.