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Extreme Cold Starting

Otto Mattik

board member
Joined
Dec 24, 2015
Location
Upper Midwest more or less
During the recent "Arctic Vortex", I had a bugger of a time starting the 240.
It got to -28f overnight, & later by noon it warmed up to -14f, so set out to try it.
It would turn(slowly) with spotty igniting, cranked & cranked while it was trying to fire until it finally started up. It was not a pretty sight.



1992 240 a) 762 injectors b)new NGK BPRES 6 gap verified c)new Bosch cap/rotor d)new plug wires e)typically run 87-e10 or non-oxy premium f)5w30 syn or was it 10w30syn? oil g)new batt 660cca h) 951 ecu i) MAF is good

(old Bosch plugs were perfect light tan color)




I'm a bit stumped why it wouldn't fire ? (fuel not atomizing? theories welcome)
I suppose check for vacuum leaks ?
Does someone have a favorite brand of Injector O-ring ?
(I've heard Viton makes a good product)


Thanks in advance
 
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Move farther south or buy some of this.
https://www.walmart.com/ip/Super-Tech-Engine-Starting-Fluid-11-fl-oz/21618347?wmlspartner=wlpa&selectedSellerId=0&wl13=3831&adid=22222222228025394652&wl0=&wl1=g&wl2=m&wl3=80392907928&wl4=aud-482018033502:pla-111021284448&wl5=9008590&wl6=&wl7=&wl8=&wl9=pla&wl10=8175035&wl11=local&wl12=21618347&wl13=3831&veh=sem&gclid=CjwKCAiAqOriBRAfEiwAEb9oXfNqF59jMETdX11-v8hbtjO9JThaKJNVVedN_9oTDvl_Tz0MmN4NsxoCeO0QAvD_BwE

73e1c4aa-82d4-4f90-8b50-92163ac9a479_1.d514c4db23e4aed4194678440985ee88.jpeg


I'm sure they change the blend of gas for your area but that's pretty dam cold.
 
Baby it's cold outside!

It is turning slowly because the oil gets thicker making it physically harder to crank the engine and the battery chemistry puts out less current at that temp to the starter motor.
 
If the oil was 10w a change to 5w or even 0w would be great. A redblock should start at -30c/-23f if everything is ok. Mine usually have been turning slowly, but still started quickly on gasoline (95e10 RON / 90e10? AKI).
E: A block- or hose heater element would be great, too. Makes a huge difference.
 
Does your engine have a fifth, blue colored cold start injector? Does it work? (remove and apply 12V on its terminals)
E10 does not help with cold starts though.
Stronger ignition could help a bit I think, like a good wasted spark setup.
An even thinner oil would definitely help the crank to spin faster, which would lead to quicker startup.
 
I see probably 5 to 10 -15 deg f starts every winter. My '93 just cranks slow 4-5 times then rumbles to life. I have a S60 battery in there (i.e. it's big) and 5w-40 oil.

I haven't had it happen in the past few years, but I've had trouble starting in extreme cold due to what I think was ice in the fuel lines. It's happened 3 times IIRC in my 16 years driving 240s. I've had luck getting them going by disconnecting the fuel line at the fuel rail and cranking or running the fuel pump a bit. I don't really know know what the root cause is but that has always worked. Now, I usually put some dry gas in 1-2 times during the winter to get any water out of the tank.
 
Thanks for the many and varied responses;

VB42- Move south :lol: ...and good ole ether, not too shabby ;-)
RacerX- Yeah it was cold outside, doubled checked and it's 5w30syn :thinking:
Acke- I've had good luck w/ 5w20 & didn't have block heatr option on first night but used a magnetic heatr on th 2nd night :nod:
petiww- No cold start injector LH 2.4 version that I have or seen, & thanks I've heard same about ethanol ;-)
tjanson- Interesting process altho I've heard that an advantage to ethanol is not needing a fuel dryer :thinking:


I'm still leaning towards one or more leaky injector seals, and plan to investigate hopefully Friday or Saturnday
 
The cold saps the battery voltage,I run 15-40 and the biggest battery that will fit in the car, I also straight gas no alcohol mix for me, is viton a brand of o-ring ? Or is it a type? Like buna-n, teflon,ect
 
As you know. Ethanol is usually the chemical in fuel dryer that mixes with the water so you can have it pass through the fuel system. There can still be a problem called phase separation which can happen where the alcohol and water mix but are separated from the gas and cause lack of fuel to the engine. That might be what happened so flushing the system like you did would have fixed that.

Viton seals are better but are also a bit tougher sometimes to install. I don't know a specific brand to suggest. There is an injector place here in nj that has great prices on the repair parts. Their cleaning service seems reasonable but I haven't used them. https://injector-rehab.com/shop/home.php
 
If it is cranking slowly, you could:
Try a magnetic oil pan heater
Try a battery heater (build your own)
Or both

Both of those things will dramatically improve how the vehicle starts. Remember that most wear occurs on cold starts. So having warm oil is very important.
 
Keep in mind that for many EFI systems the programmed fuel-air mix for "cold-cold" cranking and starting is near 2:1. A large amount of injected fuel is lost to condensation on cold intake runners, ports, and valves, and evaporation is poor so it needs to be able to shoot a lot of gasoline in to get a mixture that will ignite into the cylinders.

Have you tested your ECT sensor? Needs to be working just right to make the open loop fueling correct for starting and running well in those temperatures. They can sometimes have drifted readings that can get masked after warmup when the O2 sensor trims out the error so you only really see the problem when you need it to start and run well from cold.

Lower AKI fuel is best for low temperatures since it is slightly more volatile. The same properties of high test fuel that help you avoid detonation in a hot engine hurts when you want the fuel to ignite at -20F.

Strong battery and starter with good clean terminals and connections on both ends help with cranking speed. If it rolled over slowly even with a new battery and lightweight oil might be time to clean the connections and make sure the battery is getting a full charge when running.

Vacuum leaks wouldn't be a likely issue for a slow cold start, the IAC runs wide open on cold crank and that combined with the slow and irregular RPM means there is very little manifold vacuum. Rubber O-rings do shrink and harden in frigid conditions so if it idled rough after starting you might pinpoint those injector seals then, but they won't delay it firing.

I run 0W40 oil and the difference in cranking speed and time for it to build oil pressure is noticeable when the temperature gets to -20 or below. 5W30 would be almost as good but 10W30 will slow you down.

Temperatures that cold are a challenge for any engine, let alone a caveman style engine design with 30 year old engine management technology, so if it fired eventually you have cause to celebrate even if you had to twist the key a little longer. ;-)
 
If it is turning over slowly... that is all battery/wiring/starter related. Put in 0w30 it will help, but it really should be able to start up just fine even with 20w50 down to some pretty low temps if everything else is ok. If your battery is new I'd make sure all your wiring connections are clean and tight... cold can make them flaky too. You may just need a new starter it could be weak. My car started fine with its original starter a few years ago (starter was... 25 y/o?) but I swapped it for a fresher looking one when troubleshooting a different issue and whoah... it cranked way faster than it did before. New starter brushes/bearings/whatever were healthier... more torques...
 
It never really turned over slower than expected for the temps, but I'll check the starter connections & clean if I'm feeling froggy.(probbly a good idea to have starter tested at some point)

The cold weather really kicked my a** again today, & to top it all off, I also have an unsolved heat issue which I suspect is debris slowing the core flow. It is fine at temps above 0 degrees (f) but much below & heat is questionable. Ok I'll look into some of your suggestions this weekend, thanks for the input !!
 
on a car as old as yours (1992?) you might want to check the ground strap between the block and the battery. These straps are exposed to the elements and slowely corrode. And a corroded electrical connection causes increases resistance in the circuit making the starter turn slower.
If that strap looks greenish and dust falls out when you touch it it's time to get a new ground strap. Cleaning the battery clamps and terminals is a good thing to.
 
Good advice, there's very little corrosion under the hood, the car turned over slowly because it was -28f overnight, it didn't turn over slower than normal for those temps(sorry if I didn't make that clear). Battery is new, connections are clean, ground is clean.

I replaced the ECT about 1 1/2 year ago, but good idea to test thanks
 
I remember starting my old Saab 900 when it was around -15F or thereabouts. It started, but it certainly didn't sound happy... and in hindsight, I felt bad for asking it to start. Ah, life in Minnesota.

If you're routinely starting a car in those temperatures, you really need to look into adding a block heater, or parking in a garage.
 
I realize that at -14F, one is likely loathe to take this measurement...
When the engine is worn and that cold, you're likely to produce less vacuum at idle until it's warm.
Does it maybe run better, when first started, if you open the throttle enough for at least ~2250rpm? Sometimes this can be enough to get more/ample vacuum, that I imagine is a result of better ring seal (or more attempts per second) due to the extra speed of flinging pistons around.
For a good while, I was convinced that the unsavory aspects of the way my Volvo ran in the cold were ignition related, but it turned out to be fuel-related, as a result of low vacuum.

If you have a warm place to work, or even if you wait until summer to tinker...install a nice stepper motor vacuum gauge in the passenger compartment, lots of options and mounting locations available, and then see if you observe a correlation between symptoms present and vacuum levels. It never hurts to have more data.
 
Assuming the engine has basically healthy / even compression cold(ish) (tan colored plugs are good)...

0W slippery oil really helps.
Low octane volatile fuel without too much water in it/Aviation anti-gel additives for piston engine aircraft flying in cold fog.
Battery blanket/heater.
Block heat is easier on everything, but the 0W oil and getting a largish battery warm enough to actually pass some current (assuming the connections are clean) is a real problem piece of the puzzle.
You can use a 240-DIesel battery tray and sized battery if you're really paranoid, but it shouldn't be absolutely needed/don't panic.

There was an update for 556 and earlier 561 ECUs to a better cold starting program on the chip as they had problems cranking a little too long and/or borderline flooding out, as those were problematic in the earlier LH2.4 N/A cars. Install a later # ECU, it's well documented on brickboard some of the problems with those.

Later updated LH2.4 ECUs have a MUCH better cold starting program I can attest to if all is tuned up tip top/triple checked and verified to work right and otherwise stock on a later LH2.4 car.
The MAF and coolant temp sensor also need to work properly.
Couldn't tell you on any dirty or kool-aid injectors hacked in there.

Block heat, nice as it is, is sorta a band-aid for the wrong weight oil. 0W modern slippery synthetic oil is really an amazing god-send.

That said, it'll save a lot of engine wear/fuel consumption due to poor fuel atomization, but cold starting should probably be tested ~weekly to verify that it fires and doesn't/won't strand you somewhere that block heat isn't available/potentially remote/life threatening.
Best place for a no-start/cold start test run failure. obviously being in your own driveway...one would think...

Still, with the correct weight oil, block heat etc you can save 20-30% fuel as well as the VAST majority of engine wear & tear when it gets really cold and just test really cold starting ~weekly "just in case" and have heat as soon as you enter the car, test that it starts, shut it down, and block heat it to prevent wasting fuel? :lol:

With 2000W(+) 12V inverters so relatively inexpensive now, you ought to be able to heat the block and battery itself with only the starting battery if you wait a minute to first warm the battery even if if you can't plug into grid power (ideal) to accomplish those goals. The poor starting battery and engine will last considerably longer and provide better fuel economy with that done.

There's a (relative) TON of energy in a strong starting battery (even tho it's not "deep cycle") if you can access it by warming it even very slightly and enough to heat a half gallon of coolant/engine block for 10 minutes to pretty warm temps...easily a kilowatt hour or two in there plus enough to hit the starter to crank it over without hurting the battery's lifespan. The block heater is only ~750W-1kw for a really powerful one in most cases screwed into the block...comparable to your coffee maker running for 5-10 mins.

Working airbox t-stat is also good for economy/longevity if the car is N/A.

It's a fine dance at those temps to get it to fire from stone cold, have already scraped your window/ripped the tarp/magnet off the top of it if you planned ahead/avoid scraping it all together if it's parked outside. Then, nnce it fires, you want the airbox t-stat to work feeding it warm regulated ~80?F air mixed off the exhaust which gets hot in about 10-30 seconds and spend as little time as possible running rich/idling/washing the cylinders down and drive it gently at very light load burning as absolutely lean as possible.

TL;DR OT below:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Charging a Tesla or new Nissan leaf with the elaborate liquid coolant battery temp maintaining system in extreme cold is a real challenge for this reason...if the car's outside you're basically just treading water with a 110V 20A circuit.)
The new leaf has an elaborate VRF heat pump to at least *try* to use less energy to deal with heating/cooling the cabin and battery pack, but that cold it's hard for even a heat pump to work/perform its defrost cycle / find much heat without an absurdly large heat exchanger coil and insulated hat to cover the coil for the defrost cycle and a 220/more powerful charging source is needed and/or semi-climate controlled parking space. (Resistance) Pan heater on a heat pump nearly nullifies the efficiency in very cold/very low lying fog conditions, but will get you by in those very adverse conditions. Building an insulated cover for the heat pump to cover it tightly to the ~56?F ground and keep it out of the cold air next to a black painted surface during daylight hours under an eve for the "run against itself" defrost cycle whilst save trying tosave some kilowatts...difficult to automate it like reactor control rods being dropped.

K-jet is better optimized for the cold than LH-EFI, when it works right...the cold start valve sprays a fine mist at 60-80psi very briefly and the fuel injectors are variable nozzles spraying right at the backs of the intake valves instead of waiting forever for the LH-EFI injectors shooting a constant spray pattern/pressure having all the fuel condense on the cold intake port walls until all that coolant/intake reaches operating temp with a bunch of (liekly) very cold to (at best) ~80?F (airbox wax-pellet-t-statically controlled) air flowing over said port walls until they reach ~180?F.

Obviously, you don't want the airbox t-stat to fail on the LH-EFI cars in the summer, at risk of possibly frying the MAF/AMM...so that has to be tested/looked after periodically/seasonally. Doubtful failure of that part has any measurable adverse effects on the longevity of the K-jet cars at all...maybe slightly reduced power under full load in the summer with it malfunctioning/drawing hot air off the exhaust much like leaving the carb heat on in a small airplane?

For very cold weather, I'd put a piece of board over half of the radiator on the intake/airbox side of the engine and de-intercool my 245Turbo for cold running and hook the airbox t-stat back up with the front splash pan on it to keep all of the engine bay sufficiently warm. Note the old 122s (with "hard"/no clutch mechanical fan to be fair) and SAABs had a window shade for half/all of the radiator for cold weather. The fan clutch would never engage the cooling fan whatever until it got above ~20-30F at least even with 1/2 of the radiator surface area missing. Not that anyone these days wants to be bothered to deal with having to actually *do* anything seasonally, just want to get in and go!

Had the intercooler/throttle body ice up on me once in the fog in Canada in a borderline life-threatening moment (just like an old school small piston engine airplane flying in cold fog with carburettor heat off) with no one around for 100km. Air intake temp is only about 70*F non-intercooled on those really cold days anyway!

Best of luck, that's all I know/don't know/have experienced.
 
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