1991 Volvo 240 Stalls Slowly & Dies In Hot Weather

[jepedoelph]

Greetings to My True Family,

This is my first post, created on the first day of my becoming a member here. Since 2014 I have been doing all of the work on all 5 of my vehicles, 2 of which are Volvos. I own a 1991 240 DL Sedan and a 1965 122s Sedan, both 4 door. I have for nearly a decade been reading constantly what is posted in this forum (and others online). So far I have yet to find an answer to the 240 stall problem described below. Perhaps I have missed a previous post which holds the solution to the problem and someone here might provide me a link to that kindly.

FYI: I am NOT EVER taking my 240 to a mechanic again. Those days are so over.....you know..... like the days of my family and me being able to buy groceries peacefully without getting cussed out and screamed at by ignorant hordes of masked tv loving 100% public miseducated moronic sheep who literally know nothing about biology or what constitutes the human virome. May my fellow 240 lovers forgive this, my thoroughly intended digression.

THE PROBLEM: Slightly uneasy idle (very slight). Car does not like going up hill and is sluggish when attempting to accelerate or when under load. Car will stall, especially in hot weather above 90 degrees F or after prolonged driving in moderately hot weather around 80 to 90 degrees F. Wait approximately 10 minutes for the hot engine to cool down just a little and (((presto))) the engine can be restarted with no problem. The longer you wait and the more cooled down the engine - the farther the car will travel once restarted - depending on weather temp of course. Sometimes while slowly dying (on the freeway in a state like New Mexico where human populations drive way too fast and have no patience for anyone including themselves) the engine will surge a tiny bit - like what I recall my old lawnmower doing back in Texas when I would cut the gas and then give it a little gas and then cut the gas again.....back and forth and so on......until the 240 dash cluster lights all light up as the engine is fully killed and you best not still be in any lane whatsoever. You will get a hint that the engine is about to perform this theatrical drama - it will cut out for a fraction of a second - like a hiccup - and then it will continue as normal. You'll think it was your imagination or that you hit a spot in the road that would cause such a disruption to the forward motion of the car - but no. It happened and it was the engine cutting out for a tiny brief moment. Then, about 10 seconds following said hiccup....the above mentioned slow dying process begins - like you are slowly turning off a water spigot. It feels like the gas is being slowly but surely cut off in some way, but I cannot say for sure it is fuel or spark. But if it was spark or ignition - would it slowly die like this??? The amount of gas in the tank is of no relevance. Whether the tank is full or near dead empty, we care not at all. Something is ultimately getting heat soaked to a point of failure. Turning up the blower motor and blasting my family with supremely hot air in an already hot environment seems to stave off the engine's death.

So in this order I find me:
Sweating bullets in a car that is blowing engine heat on me in the southwestern desert during summer > DEATH > Wearing a mask at any time. PERIOD.

As you can see below, I have done quite a bit of part replacement so far.

When the problem began exactly 2 years ago this coming December, I cleaned the MAF and thought I had found the cause and all was well. How dreadfully wrong I was! I have replaced the following with 100% OEM quality: Pre-pump and Main Fuel Pump (both are recently re-tested). Fuel Filter, Sending Unit, Gas Tank (sandblasted and Line-X outer prior to installation), Gas Cap, Air Filter, Plugs, Fuel Pressure Regulator, Battery, Coolant Temp Sensor, Crank Position Sensor, Thermostat, Coolant Hoses, Water Pump & Gasket, Throttle Body & Intake Manifold Gaskets (both while having the manifold totally torn down by me and soda cleaned by a shop back to brand new - I cleaned the throttle body myself by hand - everything disassembled and reinstalled to absolute perfection), Intake Air Hose, the entire PCV System including the return hose into the crankcase - yes!, Oil Pump O-Rings (the oil pump itself I disassembled and fully cleaned w/ all tolerances checked prior to reassembly & re-installation), Timing belt & Tensioner, Oil Pan Gasket, and (last but not least) the Fuel Pump Relay. Let's be clear - The problem is NOT the Fuel Pump Relay.

I have also replaced the rotors and brake pads, removed that ridiculous metal pre-heat hose from the exhaust manifold, replaced certain broken gears in the dash cluster so that the odometer may once again function as originally intended, installed the IPD automatic overdrive bypass, cleaned and fully restored the backup light pie switch at the shifter, and replaced the transmission linkage bushings. Lot of other corrections and fixes to mention - but you're not here to read a novel and neither of us are getting paid.

My 240 just turned 200k miles on our recent drive to buy organic raw milk and yogurt from an amazing farm south of ABQ - I estimate that it may have approximately 30k miles more on it.

Note: The Fuel Pressure Regulator is about 5 years old.

My hat is off for weeks to whomever can advise me on this front.
I am most thankful indeed for your time and understanding of these amazing vehicles.
"We never sell a Volvo 240. We only collect more of them."

[lummert]

If your car has a Bosch ignition power stage (or ignition module as some will call it) did you check it out or replace it? Wait, is the engine overheating?

[volvolugnut]

Ignition coils can overheat and slowly kill the engine. They are more likely to fail when it is hot and they are old. The internal insulation breaks down. You could check the resistance, but it may read fine until it gets hot. A Volvo original is best, but a suitable 12 volt generic should work.
volvolugnut

[jepedoelph]

If your car has a Bosch ignition power stage (or ignition module as some will call it) did you check it out or replace it? Wait, is the engine overheating?

First I thank you for responding. Yes, I believe my 240 has the Bosch power stage (driver's side forward engine compartment behind the headlight assembly) - but I have not looked into it. To be honest - this was a suspect part in a list of 3 parts that so far also includes the IAC and the O2 sensor. But the vehicle is NOT experiencing misfiring to my knowledge - at least not on a scale that I have experienced with my 2001 BMW e39 540iT (I have two e39 540iT). And no - the 240 2.4 engine is NOT overheating. I removed the averaging board out of the dash cluster - pretty much the only mod I have attempted on the 240 thus far. So I am seeing exactly what the engine temp is doing on the dash - although I admit I do not know the exact temp.

[jepedoelph]

Ignition coils can overheat and slowly kill the engine. They are more likely to fail when it is hot and they are old. The internal insulation breaks down. You could check the resistance, but it may read fine until it gets hot. A Volvo original is best, but a suitable 12 volt generic should work.
volvolugnut

Thanks so much for your response. I really appreciate all of you more than words can relate. I had indeed read somewhere that the coil (I think there is only one coil servicing all 4 spark plugs via the distributor - driver's side above the wheel well) could be a problem - however I, in amateur fashion, was thinking that the coil was fine if the engine started and ran. And how, therefore, would my keeping the blower motor blasting hot air over the heater core and into the cabin affect the temp of the coil since the coil is not directly wicking heat from the engine block? Or is the perceived positive effect of blasting of the blower motor just my complete imagination and my doing so does nothing in reality to stave off the engine dying as described? My thought has been that the problem has something to do with the engine heating past a specific degree and then something within or connected to the engine was getting heat soaked. Let me ask you this - Would a dying ignition (but still functioning) coil cause the sluggish acceleration in general and especially when climbing a hill? The car, as it sits now, does not care to move past 65 mph on flat grade and if I can keep it at 45 to 50 mph on something like a 15% uphill slope I'm feeling like I'm winning the lottery. We all know the 240 DL isn't called a brick for nothing - but we all also know better than to believe that these cars were designed to get us run over on the freeway!

[volvolugnut]

The coil can overheat from it's own internal electrical resistance. The cabin heater should have no effect other than, by the time you get cabin heat the engine has run long enough that the coil may be hot.
On 240 engines, only one coil served all 4 spark plugs. Borrow a good coil or get a used one from a salvage yard to try.
What you describe could very well be the coil failing.
volvolugnut

[jepedoelph]

The coil can overheat from it's own internal electrical resistance. The cabin heater should have no effect other than, by the time you get cabin heat the engine has run long enough that the coil may be hot.
On 240 engines, only one coil served all 4 spark plugs. Borrow a good coil or get a used one from a salvage yard to try.
What you describe could very well be the coil failing.
volvolugnut

Per your kind advise - I have ordered a brand new Volvo ignition coil and Bosch power stage (ICM) from.......one of my favorite euro parts websites (because they give me free shipping on low cost orders and everything always arrives way ahead of schedule - and they are always kind and informative on the phone when I call them - unlike other online sites I could buy from).......so I will be back by the end of the week (I think) with some kind of result. It may be early next week though. Also ordered a new tube of Thermal Grizzly Kryonaut thermal paste for the ICM (I needed it anyway for all three of my PCs at home - so I will be therefore killing - or reviving should I say - 4 birds with 1 stone). I know we roll with "don't start replacing parts until you know for sure....." but I seriously do not have the luxury of time. My heart tells me that you are right about the coil heating up and then failing - but I really think the stall is occurring at or above a certain engine compartment temp. Maybe by my running the blower I have reduced the engine block temp by a tiny bit and this has been enough to lower the engine compartment temp by just enough - depending on the weather temp outside. I might be reaching here - but that's where this whole endeavor has delivered me. Just to add some extra info - the lower engine shield was torn off a long time ago. Replacing it with another but even more craptastic plastic shield (all I can find on a certain Volvo parts website) for it to just fall off again isn't my style. I'd rather fabricate my own outside in the dead of an arctic winter. The air dam found beneath the front bumper is also gone. I've also just recently (long after this hot stall problem began in Dec 2018) lost the auxiliary fan unit forward of the radiator. That heavy thing was hanging by one mount! The A/C has not worked for god knows how long - like 2 decades due to a leak somewhere - so the aux fan is not too crucial - unless I am wrong. I am always open to being wrong, except for when it comes to mask wearing. I implore everyone to PLEASE research hypoxia and what constitutes the human virome like your Volvo 240's life depends on it. I find it quite odd that so many people tend to their pets and vehicles with such amazing care - but then refuse to apply the same care when considering their own health. I need my Volvo peeps to be informed and as healthy as all get out (a Texas phrase meaning "as all hell"). Thank you so very much volvolugnut......I shall return!.....

[jepedoelph]

The coil can overheat from it's own internal electrical resistance. The cabin heater should have no effect other than, by the time you get cabin heat the engine has run long enough that the coil may be hot.
On 240 engines, only one coil served all 4 spark plugs. Borrow a good coil or get a used one from a salvage yard to try.
What you describe could very well be the coil failing.
volvolugnut

Sorry I took longer in buying the coil and power stage than I had previously thought - and I wanted to give my 240 some time to give me feedback on what I did to resolve this HOT STALL.

I'd like to report back to anyone reading this who may have the same problem(s) that I have had regarding a HOT STALL on a 240.
If your 240 dies in heat - and then you can start it back up again in like 5 or 10 minutes of keeping the hood open for ventilation, then you probably need to replace your ignition coil yo.

I installed a brand spankin' new Bosch ignition coil about 3 weeks ago - I paid about $90 for the real deal and was not willing to chance more problems by obtaining a lesser product. No, the new Bosch coil was not made in Germany, but it's pretty legit from the outside as far as I can tell.

Immediately the car now has more power and enthusiasm for the road. No, it still does not enjoy steeper hills here in New Mexico - it does bump down to 4th gear at about 45 mph when pressing the gas on an uphill climb - but perhaps that's just the 240 design showing its horsepower and road limits. There has not been a single hot stall yet since the coil replacement. I do still feel like there is a minor rough idle at times, but I've yet to restore any aspect of the head - and all of the injectors are still OG just for starters. So there's still lots of room for improvement and I am always far from finished.

I did also buy a new OE Volvo power stage - but I have not yet decided on which thermal paste to go with - so I will be replacing the power stage near the driver's headlamp very soon - and I will likely return here to give an update on what that does to the 240's performance.

Massive thanks to those who took the time to write to me and help me out. Volvolugnut gets a huge salute.
Remember to toss out your tv set(s), question EVERYTHING, and burn those face diapers, I mean masks safely in the nearest fireplace to save you.
Cheers!

[volvolugnut]

The coil can overheat from it's own internal electrical resistance. The cabin heater should have no effect other than, by the time you get cabin heat the engine has run long enough that the coil may be hot.
On 240 engines, only one coil served all 4 spark plugs. Borrow a good coil or get a used one from a salvage yard to try.
What you describe could very well be the coil failing.
volvolugnut

Sorry I took longer in buying the coil and power stage than I had previously thought - and I wanted to give my 240 some time to give me feedback on what I did to resolve this HOT STALL.

I'd like to report back to anyone reading this who may have the same problem(s) that I have had regarding a HOT STALL on a 240.
If your 240 dies in heat - and then you can start it back up again in like 5 or 10 minutes of keeping the hood open for ventilation, then you probably need to replace your ignition coil yo.

I installed a brand spankin' new Bosch ignition coil about 3 weeks ago - I paid about $90 for the real deal and was not willing to chance more problems by obtaining a lesser product. No, the new Bosch coil was not made in Germany, but it's pretty legit from the outside as far as I can tell.

Immediately the car now has more power and enthusiasm for the road. No, it still does not enjoy steeper hills here in New Mexico - it does bump down to 4th gear at about 45 mph when pressing the gas on an uphill climb - but perhaps that's just the 240 design showing its horsepower and road limits. There has not been a single hot stall yet since the coil replacement. I do still feel like there is a minor rough idle at times, but I've yet to restore any aspect of the head - and all of the injectors are still OG just for starters. So there's still lots of room for improvement and I am always far from finished.

I did also buy a new OE Volvo power stage - but I have not yet decided on which thermal paste to go with - so I will be replacing the power stage near the driver's headlamp very soon - and I will likely return here to give an update on what that does to the 240's performance.

Massive thanks to those who took the time to write to me and help me out. Volvolugnut gets a huge salute.
Remember to toss out your tv set(s), question EVERYTHING, and burn those face diapers, I mean masks safely in the nearest fireplace to save you.
Cheers!

The 240 4 cylinder does not have great horsepower or torque. It is to be expected that the transmission (assume you have overdrive automatic) will downshift climbing a steep hill. Glad the coil helped.
volvolugnut

[jepedoelph]

Hello to all,

Nearly 3 years have passed since I began this thread.
'91 240 continues to stall as if none of the work performed (or parts replaced) as mentioned above ever happened.

For all, especially those silent readers reading this (as I was silent for a long time myself), I will add that I:

#01 - Replaced the ignition control module behind the left front headlight using high grade thermal paste in the fall of 2021 and...

#02 - Fully tore down and rebuilt by hand the original alternator - finished it in high temp gloss black and had it bench tested by an ancient in October 2022 on his machine from a 1950's sci-fi film.

Belt squealing alerted me to there being a problem, I checked everything and found that the alternator tensioner bracket 8mm bolt had fully sheared off at the mating surface of the engine (the rest of the bolt long gone) and the bracket was dangerously flirting with the crank pulley - the pulley having eaten into the bracket by a bit. Good times.

On that note, in case you ever have THAT problem and, like me, cannot extract the og bolt using every extractor set known to Zeus....I finally got even with it by carefully drilling the bolt out (careful with depth of bit because a coolant jacket is located directly behind as I understand) and installing a Time-Sert sleeve to bring the 8mm thread back. The Time-Sert products are made in the USA and by god they are worth every fake, fiat copper-plated zinc penny you can find in a parking lot.

Since late 2018 we have lived in Santa Flush, New Mexico, far east Idaho near Jackson, WY, and now finally northwest Arkansas (the best of all three so far - although, like the other two, there is still no Volvo dealership or worthy mechanic to speak of). The 240 died in all of these places religiously - the Volvo discriminating not at all against place or elevation. There are, however, certain people he does not care for much.

And again it stalled out late yesterday leaving my family and me fully stranded in the middle of "no cell service north central nowhere Ozark Mountains, Arkansas." Thankfully, and not surprisingly, it was not the wonderful rural people of Arkansas who stopped to help, but indeed two traveling fellow Texans (birth state) from south of Austin who on their summer vacation stayed with us a couple hours trying to help diagnosis the problem I've been sadly staring at since late 2018 - this while also lending their working phones for us to call State Farm for the nearest tow truck more than 90 minutes away. Never judge one's politics by one's automobile, I say!

My point in relating the above: During the 2 hour ride back home, the tow truck driver listened to my description of the issue and he suggested that I revisit the ignition control module since everyone he knows carries 3 or 4 extra of these in their trucks at all times. Who knew? The people of rural Arkansas, that's who. I only have 3 or 4 fuel pump relays in my car at all times. Says he's replaced a brand new one right after he installed it.

He also suggested that I not use thermal paste and that I space the module away from the body metal where it sits in order to allow heat to dissipate via air. But really? See, I'm certain that a faulty ignition control module can produce this stalling business but would it cause the headlights to be very dim while the engine is running? This is what I noticed the very last time the car started on the side of the road last night - the engine finally started back up but I saw that the lights were very dim and I immediately shut everything off.

"That a whole nuther lil clue.
Surprisn' as all get out.
Better 'n yeah."

At the very least - I think "the collective we" here can definitely see this problem is electrical in nature and has nothing to do with fuel delivery. As always, anyone with advice is greatly appreciated.