Hello I'm new to the site, but not to the world of mechanics.

However I'm having trouble with my 1986 245. It was running fine, but then I decided to take the engine harness out to rebuild it. I did so and now I have no power to the fuel pump. I can jump terminals and here the pump run so I assume the wiring isn't broken. I've replaced the relay, still no start. Thinking I may have fried the brain I pulled a new ecu from a parts car, still no start. I have great spark, the main 25amp fuse is good. The fuel pump fuse (#6 i believe). I don't know what my next step is. Should I have power with the key on engine off (koeo) or is it only when it cranks?

Thanks for your help.

-Clark

Hi Clark,

Have to go by memory here, but I seem to recall there's a (gray?) wire that runs from the Volvo/Chrysler ignition harness to the Bosch LH2.2 engine management harness in order to provide the fuel ECU with ignition signal. The connection, if I recall, an insulated spade type, is under the intake manifold. Without this signal, the ECU will not supply the ground to the fuel pump portion of the fuel injection relay located above the front passenger's toes. This is a safety feature, and the reason the pump does not operate until you crank.
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Art Benstein near Baltimore

You're getting old when you get the same sensation from a rocking chair that you once got from a roller coaster.

Thank you. I think that will point me in the right direction. What does this spade terminal connect to?

Art's said it better than I can but: the spade terminal goes to a sensor. In 240s (a phrase I learned here) "spark trumps fuel" ie. the ECU won't run the fuel pump if there's no spark.
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240s: 2 drivers and some parts cars

Hi Art,

Not to question your memory, but if you're right I would question why "they" would route that critical wire so round about, when the ICU and ECU are both on the right side of the car. Or am I missing something related but not obvious to me?

Anyhow, this will bump the thread to the top for a while.
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Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Hi Bruce,

I'm thinking you were in on this the last time it came up. Real memory test, I'm sure. I understand your question, because we had the identical common sense skepticism when it came up before.

At that time the very same circumstances were cited: a replacement harness and afterward no fuel. The signal to ECU from ICU is on a gray wire from pin 8 of the ICU to pin 1 of the ECU. The ignition and "engine" harnesses mingle where the ignition harness ends about at the knock sensor, and the engine harness splits branches for the idle motor and throttle switch. The throttle switch also ties into the ignition harness, so I'm not certain there isn't a two-position housing for both the gray ignition pulse wire and the orange TPS wire. My memory says they are separately housed.

Of course you know I've never had one of these 85-88 cars, but I do remember when it came up last time I made a point of looking for it in a car in the junk yard, just to verify the location of the junction under the manifold.

The OP could probably run a jumper from ECU pin 1 to ICU pin 8 to verify the missing signal more easily than hunt for it under the manifold. There's no sensor involved as another responder suggested.
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Art Benstein near Baltimore

Forget the health food. I need all the preservatives I can get.

Success! I completely overlooked the connection. It started up and runs great.

Art if you ever make it to Reading, PA let me know, I'm buying you a beer. Thanks again this made my month and it's only the 1st.

Hi Art,

Yes, I do have vague memories of that thread, and you confirming the location and routing the ICU=>ECU signal. After my post above, it came to that the ICU needs info from the intake side (KS, TPS).

So it may have simplified the harness and sheathing to keep the gray wire with the others, rather than take the "short cut" that appealed to me.

Eyeballs glazed now from 2+hours scanning HVAC threads at homerepairforum.com for Monitor 442 info. Seemed prudent after 12 years with no attention. You might say I couldn't have cared less;-)

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