Hey there, new Volvo guy here. Just got a '93 240 Wagon at an auction for cheap. It runs, drove it 2/3 of the way home and sputtered and died.

It will start now and then but sounds like it's either starving for gas or air.

Looked under the hood (probably should have done that after picking it up at the auction but as in a hurry) and I think it's the air intake hose?? goes from the air filter sort of underneath the engine to the manifold, is missing a big piece, my missing a big piece I mean the hose looks like it was cut off 6 inches short and never repaired. On the side of the road if I put the throttle all the way out it would start and rev high but as soon as it was put into gear, nada.

As I said, it ran fine for about 40 miles at highway speed and once the speed slowed under 40mph it would start to sputter but I was able to get it back up but then finally couldn't.

obviously this hose is a major issue, if that is the intake hose chances are that is the problem? No CEL comes on or anything.

It is being towed back to my house as we speak, the wife isn't too happy but I do get evil laughs right now. I plan on going over the entire thing once I get it in the garage (definitely needs brakes too) but does this hose sound like the main obvious problem?

Thanks all

Mike from PA

 

well, is that the silver corrogated foil hose that goes from the exhaust manifold (starboard side of the engine) to the airbox? that hose is to allow the engine to get prewarmed air off the outside of the exhaust manifold when its very cold out. there's a mechanical thermostat mechanism in the bottom of the airbox that opens a flap to let the hot air in. this whole mechanism is quite sketchy, and in fact that thermo flap often jams open, and the hot air can damage the MAF, so most people will wire the thermoflap closed, and/or disconnect that hose (but don't do this if you're in an area with smog check, its one of the things they are supposed to inspect)


the air goes from the airbox to the "AMM" aka "MAF" (Mass Air Flow meter) to the throttle body to the intake manifold. The MAF looks like a 6" long 4" diameter horizontal tube with a Bosch electrical block on the side and a connector. If the hose between the MAF and throttle body is broken, then you'd get your symptoms. If the broken hose is between the airbox and the MAF, then, well, you'd be sucking in potentially dusty air, which would be bad for the engine long term, but it won't actually impact running.

MAF:


on a 93, which has LH2.4 injection, there's a engine fault code diagnostic block on the left strut tower... see the procedure for reading this here...
Engine and OBD Diagnostic Codes (same thing on a 740/940 post 1989). socket 2 is fuel injection, socket 6 is ignition, each one has its own set of codes. read both sets of codes, and let us know what you get.

the rest of that site is really useful for 240's too, as long as you realize that 240s don't have the 'radio suppression relay' that you find on 740/940, so you can ignore that. also the 240 relays are in different places, and the fuse numbers are all different. otherwise,, they are almost identical engines, transmissions, etc. http://www.swedishbricks.net/700900FAQ/FAQSummary1.html

 

UPDATE:

I tore everything down from the filter box back to the mainfold. No holes, cracks or tears.

I pulled the codes (that thing is cool by the way), here is what I got:

Socket 2:

Code 223
Code 121
Code 221

Socket 6: no codes

According to the code chart the 121 and 221 should make the CEL go on but it is not on.

Two codes point to the AMM/MAF

Any ideas?

 

Update to the update:

After I pulled the codes, started it up just for kicks, the CEL now CAME ON (was not on before). I did not clear the codes the first time I pulled them. I pulled them again (they were the same) and erased the codes this time, started it up again and the CEL is now OFF again.

Also, now I have a bulb warning light? What does that mean?

 

Whatever those codes are for, repair those problems. Sometimes the CEL does not come on unless you drive 2 cycles.

As for the bulb warning light, either you have switched your rear fog light on or you have a exterior light bulb out.

 

UPDATE

So I decided to clean the MAF before replacing just to see what happened. Also found out that the wire to the IAC?? was disconnected so I plugged that back in. Everything fired up fine and it idled pretty good for about 15 min then it sputtered again and even had a back fire.

When I got this thing at auction it actually had all the maintenance records from 2000 until 2011, a dream come true. So just for kicks I pulled a spark plug and it looked ok, a little worn, their last replacement was 5/2009. Mileage is a bit sketchy as odometer was broken and replaced but not sure how long it was driven while broken. Old one had 174K on it, new one has 14K, service record said spark plug at 177K but that is an estimate I assume.

I went back a little further and found out that the last time the spark plug wires/distributor cap/rotor were replaced was 11/2001, at 130K, so guessing the mileage at about 50K and 10 years since last changed. Woman how had the car pretty much just drove it to Canada and back a couple times a year.

Obviously plugs/wire/distrib rotor/cap need replacing, should thing help with my stalling/idle/sputtering? Assuming the cleaning of the MAF was successful and plugging the IAC back in worked.

 

I'd be looking for bad wiring and/or crusty connectors first before replacing expensive parts. some times 20 year old wiring insulation gets brittle and cracks, often where you can't see it (inside bundles), and causes all sorts of sketchy problems.

make sure the grounds are good (like, if you can get the engine running, use a volt meter and measure the difference from the engine block to the - terminal of the battery, also from the AMM's ground wire (brown, I believe its pin 1 at the AMM) to the battery -. if you read more than a few millivolts with the engine on, there's a ground problem.

the idle valve is under the intake manifold, and has two wires to it, one (may be blue-yellow) comes from the fuel injection main relay (so its +12V power when engine is switched on), and the other (might be red-black) comes from the ECU and is pulsed to ground to modulate the idle. that code indicates that the ECU can't see the juice going from the relay through the idle valve to the ECU... I'd be more inclined to suspect wiring rather than the actual relay.

the AMM is in the air path between the air filter box and the throttle body, I posted a picture above. in addition to the brown ground wire it gets power on pin 5 (blue-yellow ?) which also comes from the main fuel injection relay, same as the idle valve.

all my wiring colors are suspect as I'm looking at the diagram of a 1992 940 with the same engine and fuel injection.

with the engine OFF, you can unplug the AMM, then try to start it, it should start and idle somewhat poorly, but be nearly undrivable due to lack of power, its in emergency limp-home mode. this will throw faults, of course. switch engine off and plug the AMM back in, then read and clear faults, and test drive it again.


edit: ooops,. posted this before reading your update. probably not directly applicable anymore. yeah, get a cap and rotor, spark plugs, new GOOD wires (get Bougicords or Volvo brand wires, Bosch or volvo cap+rotor... generic aftermarket stuff is junk)

 

I actually had started it up a couple days ago without the AMM installed, not sure if that was a bright thing to do. But after cleaning it (6.99 for cleaner seemed like a good place to start besides replacing it), it did start a little stronger. The wires under the throttle thing (the technical term) were disconnected and hanging down so I put them back up. It ran solid and when I fiddled with the throttle all sounded pretty good but throttling down it would sputter and have a hard time getting any "spark", at least that is what it sounded like.

Thankfully I have the records, the fact that the plug wires and distrib. haven't been touched since 2001 can't hurt to replace, I'll see if any codes have come up since I reset them. I'll keep you posted. Thanks for all the help.

 

UPDATED Again:

Have cleaned the AMM, took out the IAC and checked it, everything seemed ok, blew it out with some air, voltage stuff was good. All hoses double checked, new air filter.

Car starts, runs fine, runs for longer than previously before sputtering out. Could run it at idle in the garage for 20-30 min before dying. Could rev it for a couple minutes at a time, let it idle, rev again, idle, rev and it would be fine for about 20 min then when brought back down to idle it would have issues again.

Cleared the codes from before and now I am getting the 2-3-1 and 2-3-2, both pointing to fuel mix. When running it does have an elevated smell of fuel, sort of a rich exhaust smell.

What should I be thinking about in the fuel area?

Thanks guys!

 

hmmm. if it runs fine cold, but has issues when warm, I'd be checking the temperature sensor on the engine block, I believe its under one of the intake ports. stealing from the 7XX FAQ on the swedishbricks site...

IIRC, there's two sensors, one for the dashboard temp gauge, and the other has two signals, one for the EZK Ignition module, and the other for the LH2.4 EFI ECU. check both of them.

The resistance values between either pin on the sensor and ground are:
32F (0C)-- about 6000 ohms within a range of +/- 10%
68F(20C) -- about 2300 ohms
104F(40C) -- about 1300 ohms
140F(60C) -- about 600 ohms
176F(80C) -- about 300 ohms
212F -- about 190 ohms

 

OK, finally had some time to look at this after funerals and vacations and such.

Again, it's starting fine, idles ok but after about 5 minutes it stalls out. MAF is cleaned out.

Cleared codes and pulled them again.

On the #2 socket I get 2-3-1 "Fuel trim (lambda control) too lean or too rich at part load"

On the #6 socket I get 2-2-4 "Engine coolant temp (ECT) sensor signal absent or faulty"

The ECT was mentioned earlier. I found it, finally, lol, there is the part that goes into the engine with the one wire attached, the connector was a little corroded but looked ok, there is a large connector with a 2 wire harness as well. Not sure how to check that with my multimeter.

The Fuel trim code is new, was not getting that before.

Thoughts out there?

Thanks

Mike

 

the ECT was exactly what I was thinking of as I read that it stalls 5 minutes after starting. when the engine is cold, it needs to run richer, once its warmed up, the EFI leans it out. if it doesn't realize its warmed up, it would be too rich and could easily stall.

you don't mention the year/model car...

but, see http://www.swedishbricks.net/700900F...eSensors1.html

the catch-22 is, different versions of the ECU/ICU may have different ECTs with different values. on most of these cars, the ECT has two pins, one is for the ECU (fuel injection) and the other is for the ICU (Ignition), both sensors are wired to ground. you can disconnect both wires and measure the resistance (ohms) from each pin to ground when its cold and when its hot, and compare them with the right table or graph for your car's version. the ones given in that article are for LH2.4, I believe.

 

It is a 1993 240 wagon. I have the maintenance records from 2000 until now (bought it at auction), it is overdue for plug/wire/etc.

For the ECT, the small one wire "plug" that goes into the engine is the ECT itself? is there anyway to test that?

The other two wire thing with the big "cap connector", the kind you have to release (like whats on the MAF or TPS), is the ECU, ICU you're talking about? How exactly do I check those and ground them? (kinda new to that part of car work).

also, I have the LH 2.4 in my car?

 

a 1993 240 could be LH2.4 or Regina/Rex. if its LH2.4 (Bosch), the ignition coil is a 'beer can' with a nipple on one end that the high voltage wire to the center of the distributor cap comes off of. if its Regina/Rex, the ignition coil is a square transformer kind of thing integrated with the ignition power unit.

AFAIK, the ECT's on those both have two pins. The ECT itself is a round thing screwed into the engine block below the intake manifolds... (checking my wiring diagrams now)

oh joy, two seperrate greenbooks for early and late 1993's. ok, both only list the LH2.4 with EZ-116K ignition, so i guess Regina wasn't used on 93 240s.

the ECT should be under and just behind the #2 intake port. it has a 2 pin connector, both wires are blue-red, one wire goes to the ECU (EFI control unit) and the other to the ICU (ignition control unit). The ECT is basically two temperature sensitive resistors, both connected to ground. you can test it by unplugging the connector and connecting an ohm meter, one lead to the engine block ground, and the other lead to either one of the pins. both pins should read about the same. you'll get one reading when cold, another when hot. the tables on that page I listed say about 6000 ohms when freezing, about 2300 ohms at 'room temperature', and about 190 ohms when boiling hot (212F/100C).

the ICU is signaling the problem (pin 6 on the diagnostic unit), so I can think of two things wrong, A) one half of the sensor is bad, or B) the wiring between the sensor and the ICU is bad. the ECT is connected to pin 2 of the ICU, and the other half goes to pin 13 of the ECU.

there are other sensors plugged into the engine under the intake manifold... one is the water temperature pickup for the dashboard gauge (single yellow wire), another is the anti-knock sensor (flat thing, with 2 wires black and green).

the ECU is the larger electronics module, and the ICU is the smaller one, both are near the firewall on the right side, under/behind the glovebox, and they each have a large rectangular multipin connector thats securely fastened to the module, going to the main cable harness that goes through the firewall back to the engine.

 

Just want to make sure I"m looking at and doing the right things here.

Here are pictures of what I'm looking at. Small one wire (yellowish) is going into the ECT in the block?? below it is a two connector plugged into a connector that is bolted on the block. Just under the second cylinder from the front

When I turn the key on (not starting), and unplug the two connector, I put one lead on the contact and the other on the engine block? when I do that I get one reading on one side but not the other. I'm assuming I'm doing that correctly?

Also I tried again this morning, it started fine, idled fine, ran it to get it up to temp, pretty much as soon as the temp gauge wasn't quite 1/2 way it stalled.

 

according to my greenbook, the sensor with the single yellow wire is for the dashboard temperature gauge only, and has no engine management function. the ECT sensor used by the ECU and ICU has two blue/red wires on a rectangular connector.

to measure resistance, the ignition doesn't need to be on (and probably shouldn't be, otherwise, the ECU likely will throw a ECT sensor code).

 

There is another plug, looks like the same 2 connector plug, behind the 3rd intake (sort of under/next to the flame trap), waiting for the engine to cool down a little, outside temp too, 97* sucks plus with big hands trying to plan my assault on it.

Is that a sensor that goes into the block? If so that could be bad and just need replacing vs. all the wires?

 

indeed, it could either be the sensor or the wiring. thats why you test the sensor at the sensor connector, you can also unplug the ECU's, and test from the ECU connector, if the sensor is good, but the signal is bad at the ECU side, then the wiring harness has an issue. if the sensor is bad, then thats the problem.

 

any tricks for getting this thing unplugged? I can get to the release (had to take some stuff off) but just can't get enough leverage to actually pull it

disregard, success!!! finally found some pliers, but still a good excuse to go buy new tools.

anyway, both were reading right about 2000ohms, not sure of actual temp, but some where between the 68-104 on the chart which should be in the 1300-2000 range, so we're probably good there.

Went back and checked the records that came with it from the auction, seems there has been a history of the same codes coming up, but they kept replacing the thermostat for some reason.

Obvious choice is to replace the sensor itself? I'm also guessing to get to that effectively I'll have to take off the injector rail and the manifold? or is there a way to do it without that? If that's the case might as well change the injectors - don't think they have ever been changed.

And finally, how do I find the part number to make sure I get the right one?

 

if the sensor is reading 2000 ohms on both sides, then I'm inclined to suggest you check the wiring. one side of the ECT goes to pin 2 of the ICU (ignition control unit, the smaller of the two modules under/behind the glovebox), and the other side of the ECT goes to pin 13 of the ECU (EFI Control Unit, the larger of the two). I'd unplug the two CU's, and check the continuity from the pin on the ECU/ICU plug to the pin on the ECT plug. yes, you'll need an extension wire for your ohm meter to do this.

alternately, leave the ECT plugged in, and measure the resistance from pin 2 of the ICU to ground, and from pin 13 of the ECU to ground, thats the full end-to-end test, if its in the correct range for the engine temp, then your problem is elsewhere.