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240 Old Volvos hate hot Southern Summers...or the Nordic gods are laughing at you.

petebee

Member
Joined
Sep 13, 2012
Location
Back in NC again...
I don't know what it is...am I simply a glutton for punishment? Why do I keep buying old Volvos for my kids to drive? Search my name on this forum and you will find several threads on old 240s that simply hate to staying running in the summer months here in the South when temps are up and humidity is high.

The current patient - a 91 240 wagon in lovely sun-faded gold - is the latest problem child. As witnessed in several other recent posts I've been chasing down problems that any sub $1K, 300,000 mile Volvo is bound to have. Trust me, I've fired up the parts cannon recently, but mainly because I had leftovers from prior cars.

So current issue is that the car, when driven for a decent amount of time then parked idling for 5 minutes in a traffic jam or parking lot to increase under hood temperatures, begins to lose power and eventually stalls. Once allowed to cool for a few minutes car will fire up fine and drive okay until the next stopping occasion.

Thankfully I was able to re-create this condition in my driveway yesterday. As I pulled in the car was stumbling and idling like crap, so I immediately went to the one component I had not touched (air mass meter), unplugged it and voila, car idled better but still a bit rough due to AMM being disconnected. I hurried to my parts bin, found my spare AMM, quickly threw it on and car idle smoothed out, power returned and all was good in the world. That was until I went out today in the heat, and drove the car until it starting acting up while idling in the Food Lion parking lot.

For the curious minds, here is a laundry list of stuff I've replaced:

Main pump (it was the original pump and very noisy)
In tank pump (it was totally dead)
Fuel sender (it was not working either...fuel gauge)
Fuel pump relay (why not, the one in the car was date stamped 2000)
Fuel pressure regulator (vacuum hose smelled of fuel)
Crank position sensor (one in the car was crumbly, and I had new Volvo one in the bin...note the old and new OHM'd the same, so the old one was working okay).

All of the above was less than $200 in new parts, so it didn't really bum me out that much.

Now when I removed the AMM I noticed quite a bit of oil in the intake bellows. I removed the tubing and the throttle body was pretty gunked up. So on the list is an intake removal and PCV clean up...it looks like it has a been a while. I cleaned up the intake bellows before putting it back on just because it bugged me.

Another thought struck me while going through my mind as to why the car would simply stop running well when good and heat soaked. I thought perhaps the AMM was overheated by the dumb warm air ducting/thermostat system failing due to the "hot air intake" mod (only needed in Sweden I guess...thanks Volvo). I pulled all the airbox ducting and stuff out, and lo and behold...thermostat was not stuck open. I yanked the thermostat out anyway, and removed the dirty accordion ducting. BTW a Castrol 5qt. bottle lid will force fit on the elbow where the old ducting connects.

So I'm at a bit of a loss. I guess I could just tell my son to pull the AMM wire when the car acts up (and likely kill the O2 sensor eventually). Frustrating thing is, the car runs so well, and as I fix some of the old clunky stuff it rides nicer, too! So yeah...they are laughing at me in Valhalla :rofl:
 
I didn't see an ignition powerstage on your list. Also make sure the coil and powerstage has clean tight connections and the coil measures within spec.

Another problem I've experienced with heat soak is an alternator that stops charging. I've had them where they work fine for about 15-20 miinutes then when temps climb it stops charging and you are driving on your battery.
 
I didn't see an ignition powerstage on your list. Also make sure the coil and powerstage has clean tight connections and the coil measures within spec.

Another problem I've experienced with heat soak is an alternator that stops charging. I've had them where they work fine for about 15-20 miinutes then when temps climb it stops charging and you are driving on your battery.

+1. I chased around a stalling/dying issue on my 92 for ages, eventually replacing in tank pump, AMM, coil, power stage, and IAC with new or good used parts. Everything would be fine for a day or two, then back to running like crap when warmed up.

After all that, checked the alternator was pretty much on it's way out. Put the spare Bosch in with a new voltage regulator and it hasn't missed a beat since
 
I can't remember if 240s have a molded plastic intake hose or something rubber, but I've had several 7/9 cars that had a collapsing intake hose that would only collapse once conditions got hot hot. Probably not the case for 240s but thought I'd mention it.

Edit: that sounds more likely^^
 
After all that, checked the alternator was pretty much on it's way out. Put the spare Bosch in with a new voltage regulator and it hasn't missed a beat since

I'll pull the voltage regulator and check the condition of the brushes. A trip to Advance Auto should allow me to get the alternator tested. Good suggestions.
 
I'll pull the voltage regulator and check the condition of the brushes. A trip to Advance Auto should allow me to get the alternator tested. Good suggestions.

Ugh...I'll wait until we test the alternator before rummaging around under there. It is a wee bit oily. Needs to be pulled out and cleaned up at a minimum.
 
You measure the charging voltage on the battery. So no need to remove the alternator to test it. In fact you want the car hot and under the conditions the problem happens. You can get a voltmeter and just run it long enough at home to check the voltage on the battery when the problem occurs.

Intermittent issues can be tough. Just keep trying. Volvos are tested in hot weather. lol.
 
^^^ good call. I'll just test voltage on the battery at start up to get a baseline, then drive it for a while, park in Food Lion, wait for the issue and then test battery voltage again. It prefers to act up in full sun, hot asphalt, you know enough to make you sweat.
 
Weird question, if you were to pop the hood and put a powerful fan on the engine, does the problem go away?

As for the alternator, by the time you spend $40 for an OE Bosch brush assembly (if needed), I’d just grab a 100amp denso from the JY for $25.
 
So I tested the battery voltage at first start up and when car started acting up. Here's what I got:

Cold engine
12.7V with engine off
14.2V with engine running

During poor idle after heat soak
Fluctuates between 13.3V and 13.9V, voltage drop would coincide with idle sputter

After a while of sputtering and ultimately dying, the car would only start and stay running with the AMM unplugged.

Waited about five minutes (enough time for me to measure voltage on my other 240), plugged AMM back in and initially car would not fire, only crank. But after a few attempts it fired up, idled fine and rev'd fine. I let it idle in the driveway for at least 20 minutes, and the stalling issue would not come back. During this time I measured voltage at battery with car running and it was 13.9V.

My other car's measurements were:

Cold engine
12.6V with engine off
14.1V with engine running

Hot engine
13.9V with engine running
 
Good testing. Seems like you are ok with the alternator. Voltage could be a bit higher and it makes sense that it goes low when sputtering.

So to step back a bit and keep it simple. Since this kind of stuff many times is electrical. I would start with making sure the plugs are gapped correctly and the wires are known good or measured. Plug wire spec for these is 500 ohms per foot. I still have the feeling it is something simple. O2 sensor is good? No exhaust leaks near the sensor? No vacuum leaks? There can be sneaky ones. Take a look at the plugs and see if they look too lean.

BTW has all this stalling set any codes? You have to check pin 2 and pin 6 in the diagnostic connector.
 
No codes other than the one that pops up when I disable the AMM (this causes a CEL, too). I'll check the wires with the multimeter and pull the plugs and measure gap/verify color. No exhaust leaks near the sensor. I don't think there are any vacuum leaks, but I will check that, too.
 
So I did a bit more troubleshooting.

Last night I misted the distributor and plug wires with water and did not witness any sparks, so it appears the wires are not shorting. Unfortunately when I tried to test wires for continuity my multi-meter started acting up, so I was unable to measure them.

The spark plugs were another story:



You could drive a Volvo through those gaps! They look okay color-wise, but I threw in a set of new NGK copper plugs that came with the car, and it did make quite a big difference power wise during my brief drive around the block.

I did find another ignition control module/power stage in my parts box, so I went ahead and threw it on. Later when it heats up more I'll take the car for a nice long drive and see what happens. If it acts up at least we can rule out the power stage and spark plugs.
 
For all these LH2.4 240s, the gospel I was taught when poor running/stalling/hard starting:

1. New CPS (good quality)
2. New power stage
3. New fuse #6 (should be all fuel, confirm it) includes cleaning the crappy holder
4. Related - clean flame trap
5. 100% new vacuum hoses
6. Clean the throttle body

These old sledgehammer red blocks, especially with the lovely LH2.4 engine management, will run damn near forever.
 
For all these LH2.4 240s, the gospel I was taught when poor running/stalling/hard starting:

1. New CPS (good quality)
2. New power stage
3. New fuse #6 (should be all fuel, confirm it) includes cleaning the crappy holder
4. Related - clean flame trap
5. 100% new vacuum hoses
6. Clean the throttle body

These old sledgehammer red blocks, especially with the lovely LH2.4 engine management, will run damn near forever.

Thanks I will address 4 and 6 when my next FCP order shows up, and I'll assess the vacuum hoses then (5).

1 is taken care of with a new Volvo CPS, 2 kinda taken care of with a used unit and I'll check fuse 6 and clean up the contacts.
 
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