I am trying to get a 240 1989 going I have spark , timing belt is ok, there is no problem with the relay forthe fuel pump or the fuses.
I can hear the main pump humming.There is gas in the tank above the level of the rubber hose to the in tank pump that may have split.
I have access to a good ECU and a good AMM from a 1990 240
I was wondering if they could be swapped to confirm or rule out these as the faulty parts.
If I have a faulty AMM or if there is a crack in the bellows air duct downstream from it could , I possibly get the car started and get going on the limp home mode by disconnecting the AMM
I heard that somme 1989 have weak ECU and was wondering if one from a 1990 could replace it . Where is situated the ECU anyways.
Any help would be appreciated.

Bearnoel

Was this car running ok for you at one time, or is this a new car to you and you are now trying to get it to run???
Larry

It is a car that iam thinking of buying.but i already have two 240s
Current owners are not mechanically enclined.they say that after some work was done on the automatic transmission the car was driven to their house and started a couple of times but is not starting One more reason to suspect the crank position sensor! ?
Since i have never driven it I would like to get it started to see if there is nothing else wrong with it. They are offerin for sale for parts and may just sent it to the scrap yard. It has approximately 200 000 kilometers or 130 000 miles I thought it should be given another chance.

Location of ECU.

Passenger side kick panel.

Open door

lift straight up on the Black plastic saddle. There are metal clips holding it down.
Trim that is running up the door jamb to the Dash...lift that a bit , slide kick panel down and off.

It helps to take off the Knee bolster too.

You must lift up hard on the stailess steel clip to pull the connector off teh ECU.
Pull the top of the connector where the wires are, toward the passenger seat.

You can plug your ECU into the harness with it hanging free BUT be sure to run a wire from the chassis of your ECU to the frame of the car ( or the chassis of the '89 ECU) The ECU should be grounded.

The '89 ecu has a part number on it...last three digits are 561....make sure your ECU has the same last three digits OR 951
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.no.net/ebrox/Tony's%20cars.htm

"...there is no problem with the relay for the fuel pump..."

How did you determine the relay(s) [there are TWO inside] are working correctly?

The Fuel relay may run the pumps for a second or two when the key is first turned on, but fail to get energized by the ECU during cranking (a known LH 2.4 ECU problem).

Or, the Main relay may fail to power up the AMM and ECU, so running pumps do nothing.

Take the relay cover off and watch the relays for the following sequence:
1 - At key ON: Both relays energize, pumps run briefly, then Fuel relay deenergizes.
2 - Key cranking: Main still energized, Fuel relay then reenergized by ECU*

* This is the known ECU failure—one that can be temporarily "McGyvered".

P.S. Are the plug tips wet or dry after some no-start cranking?


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

I ruled out the relay by putting it in the other 240 I have and that car ran fine also as the motor cranked I checked that there was curent going to the main pump positive wire at the connection just under the rear seat on the driver's side.

There's nothing like substitution to verify a part. So your ECU could well be showing the "classic" 561 failure—not grounding the Fuel relay when it gets timing pulses from the Ignition CU during cranking and running.

You can prove that failure by "back-probing" the Blue/Green wire at the relay harness plug, with a wire that is grounded at the other end. This will substitute for the (missing?) ECU ground — but since it doesn't depend on Ignition pulses, the pumps should run as soon as the Key is turned on.

If that grounding wire lets the pumps run, try starting. If it runs now, you can splice a more permanent ground jumper to the Blue-Green wire, and even add a "safety switch" to control it. Or you can make it conditional on Ignition pulses by running the new ground wire thru a K-jet Fuel relay, which works off Coil #1 terminal pulses, just like the Tach. (Details available)
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Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

You can unplug the AMM and get it into limp home mode. It would start but run rough, at least my 86 runs rough as all get out when unplugged. But it will start.

Might I suggest you get some starter fluid and pull one of the two vacuum lines off the top side of the throttle body and give it a couple of good shots. Then see if that will start the car up for a couple of seconds. That would point to fuel as the source of the no start even if you hear the pumps running. If the pick up pump was not pulling up enough fuel the main pump will run but you still get no gas to the injectors. Going to sound simple and you may have already checked it, did you check the fuse on the rear pickup pump (#4 I think).

Just an easy check before you start popping ECU and other components in and out.

Good Luck,

Paul

I sprayed starter fluid in the air filter box and it coughed up a little bit but did not really get going.Then I checked one spark plug for spark and there was some.
I may have to check all of them for spark but all connections of the cables to the spark plugs seemed okay. could I have an injector problem or a ground problem for the injector circuit(s).

As for the fuse to the intank pump I thought thta the failure of that pump would just make the main pump work harder. I once experimented on a another 240 and removed the fuse for the intank pump and the car still ran

I sprayed starter fluid in the air filter box and it coughed up a little bit but did not really get going.Then I checked one spark plug for spark and there was some.
I may have to check all of them for spark but all connections of the cables to the spark plugs seemed okay. could I have an injector problem or a ground problem for the injector circuit(s)