My symptoms are these. On start up, my 240 runs great until the engine begins to warm up. It will then begin bucking and die. I can keep it running at a stop only by keeping my left foot on the brake and applying the gas pedal with my right. My gas mileage has been abysmal of late, as you might expect. My check engine is on yet the codes at terminal 6 indicate 1-1-1 as if nothing's wrong. The AMM has proven to be good. The oxygen sensor has also been recently replaced. I've also cleaned the flame trap and searched for vacuum leaks. Throttle body is clean.

The symptoms have now begun worsening. For a while, it ran fine once I got rolling and gained rpms. Yesterday, however, it started losing power on hills and began bogging down to the point that I felt I might not get it home. At this point, it's parked until I can this solved. This car is my main source of transportation, so any help will be greatly appreciated. Jim

While we are focusing on fuel supply, is there a possibility that it may be too little, or too hot air? Have a look inside the air filter box and make sure that the flapper valve is operating OK or is blocked into the cold air position. Also that the filter is reasonably clean.

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Bob: son's XC70, dtr's '94-940, my 81GL, 83-DL, 89-745(V8) and 98-S90. Also 77-MGB and some old motorcycles.

i have been meaning to do that and I may be about due for a filter change. I know there are theories about a stuck thermostat causing early AMM demise, too.

I've not read all of the answers so pardon me if this has been covered.

Initial thought was intake manifold gasket (common problem, sometimes hard to detect)

...until you said that gas mileage was poor and it was loosing power on hills. Those clues lead me to temperature sensor. The rear temperature sensor on your car is the one that talks to the fuel injection system. It is tough to get to unless you pull back the intake manifold. Impossible if the car has EGR (Calif only, I think).

I'm leaning in the direction of the coolant temp sensor, myself ... I'll report back if this is the fix.

One of our 240s had similar symptoms recently. It started fine, then would bog down like crazy and eventually die after warming up. That could be something as simple as a corroded fuse (#4 or #6), or a fuel pump relay, or even a fuel pump on the way out, but we had already addressed all of those things within the past year so we ruled all that out. It turned out that our fuel pressure regulator had failed, and that our fuel pressure was WAY too high. Changed it, and we were back in business. It's a $60 part and a 15 minute job. If you haven't tried it, do it. Can't hurt, and even if it doesn't fix your current problem, (but I bet it will), it'll save you one more headache in the near future.


Barry

Hey Barry, I had an extra fuel pressure regulator and just put it on for kicks. It made no difference and I'm still getting the 1-1-3 code. I'm kind of wondering if I may have a bad ECU.

Before all this started happening, I also replaced the O2 sensor with a universal 3-wire (Walker) from FCP Groton, at that time hoping for a little better gas mileage. Not sure if there's a correlation or not.

"I'm still getting the 1-1-3 code. I'm kind of wondering if I may have a bad ECU."

The 1-1-3 code is definied as "Fault in Fuel Injectors". But it's been suggested that this may be a catch-all term for "beats me", since LH 2.4 has no built-in injector monitoring. Instead, "Porkface" (a true authority) says that 1-1-3 usually goes away with a new Fuel Pump relay. That's the voice of experience.

I think what's behind Porkface's suggestion here is the System relay that also lives in that white case with the Pump relay. A bad/cracked solder joint on the System relay output (87-1) can cause an intermittent "open" condition, and a momentary loss of voltage at ALL of these FI elements:
• Injectors
• AMM
• IAC valve
• ECU (pin 9 main power)
• and the PUMP relay coil

Which one blew the 1-1-3 whistle? Beats me, but I'd suspect the common source, a voltage glitch at System relay output terminal 87-1.


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

Hi Bruce, well, I pulled the relay and did find signs of cracks in the solder joints. I resoldered everything, put it back in, started her up and once again, she ran like a champ until reaching normal operating temp, then went through the same song and dance. Bucking and chugging. The check engine light came back on with the 1-1-3 code.

What do you think about trying a different ECU? There's one on a 95 940 I could pick up at PullAPart for $15 right now. Also, I'd like to know what the running fine 'til warm up situation says to you.

I guess a $15 gamble isn't too bad, if the ECU from a '95 940 is compatible with your '91 240. Personally, I would spend a few minutes and no $ to make up a "Y" jumper to replace the Pump and System relays, as a diagnostic test.
[It could be a circuit opening up when the relay warms up]

For a complete diagnostic Fuel relay bypass, a 3-legged jumper having flat male terminals is needed. This jumper is plugged into the relay harness socket, as follows:

Leg 1 into socket terminal 30 (heavy Red wire, fused battery +12V), branching to Legs 2 and 3 below:

Leg 2 to socket 87-1 (simulating System relay output)
• Orange wire to ECU, AMM, Injectors etc.

Leg 3 to socket 87-2 (simulating Pump relay output)
• Yellow-Red to both pumps and O2 heater.

As with other jumpering schemes, the pumps run immediately. For more than a quick test, a control switch can be wired into the common leg connecting terminal 30 to the other two legs, as below:

Photo by "Slowcamero" in a 2008 response to this suggestion


NOTE This jumper should NOT be left in place for normal running, as it eliminates circuits intended to disable the fuel pump in an accident.



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

Hi,

Check to make sure everything is adjusted correctly around the throttle body area.

Clean the IAC with throttle body cleaner.

Make sure all your pins for the AMM meter are positioned correctly and aligned-both the plug on the AMM and the plug from the cable.

Also as the other poster said check terminal #2 for codes.

Travis

Travis - getting a 1-1-3 code from pin #2.

the IAC is easy to test. i don't know about the 240 but in my 7 series you can test it without even removing it. just remove the plug and check the voltage and ohms via the pin. there should be something in the FAQ about the readings you should get. you can also remove it and apply 12v to it to see if the flap will open.

i tend to agree with Klaus here because the symptoms do not present themselves until the car is warm. however, a sticky IAC may not present issues until it's warmed up either. do you have any hot start problems?

Well, i believe the idle air valve is okay. I took it off, cleaned it and got good results when I put 12v to it.

I'm considering replacing the coolant temp sensor now if I can figure out how to get my big hands back there. Should I pull back the intake manifold to access it?

i was able to get at it with a few extensions and a 19mm deep socket.

I'll give that a try. I'd rather go that route than pulling back the intake manifold. I wonder if I could talk my sweetie with her petite little hands into tackling it for me ... hmmm

Try plugging into diagnostic port 2 for "the rest of the story".

Ron J

Dang, I unhooked the battery and lost my codes. Will test port #2 when I put the IAC back on.

Your symptom points me to suspect the engine coolant temp sensor. The ECT tells the computer to keep the mixture rich until the engine warms up. In your case, it never does that and you are running rich and fouling the plugs.

Klaus
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Volvos should be saved from the junk yards, not donated.

thanks, Klaus. I did pull my plugs a couple of days ago and at this point, anyway, they look normal with no signs of fouling.

It sounds very much like a bad engine coolant temp sensor. Unless you remove the wires to the injectors from the intake manifold, removing it will not help (ask me how I know). I thought it was an impossible task, but I got a 19mm deep socket on a wobble extension and it came out easy. The problem is that I had to get the socket over the sensor and had to unsnap the electrical connector completely by braille. It took 15 minutes to position the socket and I had to push the wiring harness out of the way, but getting the new one in was easy and it solved my problem immediately.