Before this wagon was prematurely retired, the engine ran flawlessly. Now after about 18 months of inactivity, I need to see if it runs.

My mechanic had taken out the ECU and the ignition switch before towing the car to me (I assume he suspected the ignition switch on another car, but found out it was the ECU). I ordered and replaced the ECU, and tested the ignition switch he had left off the car with a meter.

Putting humpty back together, it will light up and crank but not run.

I checked the Hall sensor wires on the distributor and the wires/cap/rotor.
Jumpering fuses 4 and 6 runs the pump, the 25A fuel pump fuse is OK, and the fuel pump relay clicks on with the switch on IGNITION. Both FP relay coils work fine off the car.

What's the next diagnostic step for this car?

Thanks

p.s. I don't know what else my mechanic might have removed from the car; there are two connectors dangling from beneath the steering column. Attached is an photo.

 

OK, update :

looking at my newly acquired Bentley manual, I was /NOT/ supposed to remove the connector from the ICU? (p. 280-8).

How am I supposed to test it??


I wish the '89 hadn't blown the head gasket... no such nonsense in that year.

 

Try this link: http://www.stepbystepvolvo.com/

 

The blue/ green/ white one connects just above the fresh air vent behind the driver side kick panel. Trace the brown ground wire going up and to left, it joins that plug. Can you put up a closer shot of the other one?

 

the wire color(s) and pin numbers of both those connectors would be helpful, also the pin configuration, which isn't apparent from those pictures. most of the connectors under the dash are 3x3 things. that one hanging down ont he left looks like it could be for a relay... for instance, the headlamp relay has green/red (pin 30), black (pin 85), yellow (87), yellow (86).

 

uuggghhh... what did I get myself into?!


One connector is :

************| (blue)
(Yellow-Red) | --- | (Black (2))
***********__ (yellow (2))

* (asterisk used for spacer).


The other :
************___ (blue)
(White-Black) | **|* | (green)
*************| (brown)


I don't see numbers on the connectors.

The Bentley wiring diagram lists these pins for the ICU :

Gr -> ignition coil 1
Bl -> ignition coil 15
OR -> idling/full load microswitch
SB -> ??
GR -> ECU
GN -> distributor hall sender 3
Y -> distributor hall sender 2
SB -> distributor hall sender 1
BN -> Knock sensor


uh-oh. I see some of the same colors here....

Looking at the list of relays (p. 390-3), there doesn't seem to be anything missing in that area (headlights work, and other accessories ... don't care right now). Then again, uh-hmm ... "Caution : Relay positions are subject to change and can vary from car to car..."


Maybe it would be easier to change the head gasket on the other 240!

 

uh-huh... will look into it. thanks!

 

virtually ALL of the connector-to-connector plugs have round pins. flat blades in these arrangements are almost certainly relays....



* * * * * * * * | (blue)
(Yellow-Red) | --- | (Black (2))
* * * * * * * *__ (yellow (2))



the first one looks to be the relay/timer for the heated rear window.



******** * * * *___ (blue)
(White-Black) | **|* | (green)
********** * * * | (brown)


there's a pair of relays for the electric locking system, my diagrams shows these as behind the central console air vent, one looks kinda like that.

 

The connector is tested by inserting the test probe into the connection, just slip it in next to the wire in the pin your testing.

I guess backing up for me, are you getting spark? will it run on starting fluid?
Are you getting fuel? are the plugs wet with fuel after you attempt to start?

 

When I jumper fuse 4 and 6 the fuel pump runs, but I don't hear it during cranking or smell fuel after. From what I see on the fuel pump relay diagram, this could be either the ECU/ECM or the ICU/hall-sensor/coil/dist.....

I have no +V on pin #2 of the ICU connector. I'm having trouble understanding the Bentley wiring diagram : it looks like the ICU powers the hall sensor and uses its output to ground the coil; does the coil get power directly from the ignition switch? where does the ICU get its power (to pin #2) ? It looks like a R-SB wire goes to the fuel pump relay and a BL-Y wire goes to fuse # 12 from the ignition switch pins marked "15" (IGNITION).

Also, there are two relays shown in the 87-88 diagrams : 99 ("fuel pump relay) and 217 ("Main Relay, B230 F") : they seem to have the same connector numbers, but different color wires. I've only found one relay, a double-coiled one, near the ECU under the glovebox. It is marked 89 8151 or 35 23 608. Is this car supposed to have both?

 

Before you get into tracing all this down, just get the basic facts. The engine needs spark, fuel and air to run.
- pull a spark plug wire and put a spare plug in it. Attach it to or get it close to a metal part of the car and crank the starter. Does it have spark?
- Immediately after this, remove a spark plug and check to see if there is fuel on it.
-You can also use starter fluid and see if the car fires using that, this would eliminate spark.

Your car has a combined relay for fuel pump and main(system, x). I have never been a fan of jumping from the fuses, it's a lot easier to me to jumper the fuel relay; that runs both pumps. On your relay, jumper the 30 socket(red) to the 87 socket(yellow/red). You just remove the relay and jumper the socket. I use a blade fuse 5A between the two ends.

You can listen through the fuel filler tube to see if the in- tank pump is operating. You can literally feel the main pump for operation if you are not sure about it's running.

It's real tempting to try to suss things out through wiring, just do the basic steps first to point yourself in the right direction.

Really, as rspi said: try this link-

Home ( It won't start!)

 

The stepbystep PDF agrees w/ what I was doing per Bentley : flowchart steps 4a. & 4b. : no 12V on terminal 15 OR "all inputs to power stage present" -- "trace back in ign circuit".

From :
https://volvoforums.com/forum/volvo-...53/#post368941
(posted a week before my post -- sorry!) :

ALAS! yellow-blue wire was not connected to ignition switch #15 pin!

OK I have fuel & erratic spark; when I jiggle the ICU connector things happen. Firing order is correct. Just gotta sort it out now!

Thank you all!

 

the connector on that Chrysler ICU used on those 85-88 240s is problematic. if jiggling it changes things, pull it out, carefully clean it, use a small probe or tiny screwdriver or something to gently tighten the 'sleeves' in the plug, grease it with electric silicone grease, and carefully plug it back in, pushing straight in with no rocking at all.

a few of the sleeve connectors inside the plug end have an insert in them, this is normal, it was an EC made shortly after those ICU's were put in production.