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The cold start system is disconnected. Everything else is OEM. I'm doing pre mix, and 1 pint of methyl alcohol per tank. Car insists on throttle wide open when starting cold on a freezing day for it to start wth billows of dark smoke. Battery is healthy.
No idea, but I was curious what Methyl Alcohol was good for so I googled it. This is the first thing that came up...
"When you use a methyl alcohol based product it soaks up water and prevents freezing. The problem is although the water and alcohol mix, that mixture won't combine with the gas so it stays in the tank causing long-term damage. ... To actually protect fuel system parts the water and alcohol have to get out of the tank."
Are you using it a a fuel stabilizer? I use Sta-Bil brand in my machines, never had any problems.
I drive the car year round. Winter startings are easier since I'm in alabama now instead of new jersey. When I lived in L A, cold starting was not a problem.
I think it works because it dissolves the ice from trace amounts of water in the gas tank. Pouring it straight down the carburetor works.
When things were below 0 F , the last resort is removing the leading plugs, hit them with wd-40, turn the engine over to clear the chambers, install them, and then try starting. Really really really fun to do in -20 F. Maybe the OMP pumps to much oil in the chambers and fouls the spark plugs?
Heet gas additive is methyl alcohol. There is an ethyl alcohol version. I haven't had good results with those ether sprays.
Imagine flowing oxy-acetylene into the carb and trying to start the engine.....bet it would blow up.
Ya know, you could get a new Kia for like $99 a month and save the RX for pleasure driving. How cold does it get in Alabama?? Last winter I left mine outside a few times to make sure I could start it in 20F weather, and it started up no problem. Pouring alcohol down your carb cant be good for your seals.
Last edited by Maxwedge; Nov 15, 2019 at 05:38 AM.
I used to live in Charlotte and drove all year long, my car seemed to love the cold weather. The coldest I can remember is about 8 degrees and it fired right up. It was great to only hear the engine for about 10 minutes before the fan started to catch.
I don't premix or use any additives, maybe too much oil in premix?
Never have had the choke connected
cold start assist was connected in NJ (what does cold assist do?)
$99/month??? sounds GREAT............but then I would have to drive a KIA
Some gasoline is 85% ethanol. It use to blow people's minds when I would take an empty bottle of HEET into the cleanroom to get semiconductor grade methyl alcohol to pour down the carb.
Cars that may normally be running a little rich tend to 'perk up' when cold weather comes around. It has to do with air temperature, as lower air temps equate to higher air density; which is to say that for every gallon of air, there's more oxygen to be burned with the fuel. If you're running rich in the summertime, you're probably right in the magic sweet spot when the air temp drops 30-40 degrees, as you now have the perfect mixture of air / fuel to burn efficiently and produce more power.
I'm speaking from the AZ Sonoran desert (up to 122F), as even with EFI mapping for high ambient intake air temps, the lack of power is noticeable when compared to wintertime around here. Our dead-of-winter temps are about 35-40F, and just about perfect for driving an RX7.
Since bypassing my heater core, the only thing required on those 'cold' days is a heavier jacket until the engine heats the firewall, the presilencer heats the passenger footwell, and the transmission heats the tunnel - then it's downright nice inside,
Never have had the choke connected Well there's your first problem
cold start assist was connected in NJ (what does cold assist do?) Cold start squirts antifreeze into the intake to raiser compression for easier starts below freezing. Supposedly it worked well from the factory, but 35 years of never, ever being needed has most car's system just there to junk up the firewall. Here's a pic of the bottle, with it's tiny motor bottom center, held about where it mounts on the firewall...
$99/month??? sounds GREAT............but then I would have to drive a KIA Then you would have a very functional little car that starts up 1st try in the dead of winter, AND a cool vintage sports car that you're not destroying just to prove you're still hip.
Some gasoline is 85% ethanol. It use to blow people's minds when I would take an empty bottle of HEET into the cleanroom to get semiconductor grade methyl alcohol to pour down the carb. That's E85, and tuners are making great power on it, but your old rotary isn't designed or tuned for it. If you are going to run alcohol you need a special premix like Redline Alcohol Oil. Regular premix oils don't stay suspended in oil and tend to gum up the motor.
If you hook up you're choke and get your carb tuned about right the car will start up no problem. You mentioned the plugs getting fouled and wondering if the OMP was pushing too much oil. The OMP is driven mechanically by the engine, so I don't think it can over-drive the pump, but you can check how much oil it's flowing. There's a measuring procedure in the Foxed archives and the Haynes manual. I've always thought fouled plugs were just too much fuel, so maybe it's the extra pumping you are doing because your choke doesn't work.
Last edited by Maxwedge; Nov 15, 2019 at 06:00 PM.
Oh, that. It is still in there, but I've never filled it. If shooting antifreeze into the car boosts compression , then pouring HEET down the car will do the same? Or I could pour some antifreeze down the carb?
OMP fouling the plugs, but it can't because the OMP is driven off the engine rotation...........logical conclusion. The plugs don't smell gassy when I remove them.
LongDuck>>>> that makes me feel better. Seems like the engine picked up a few horses in the cold. Been thinking about the few horses it picks up just before blowing an apex seal.
Last edited by midnight mechanic; Nov 15, 2019 at 07:33 PM.
No idea, but I was curious what Methyl Alcohol was good for so I googled it. This is the first thing that came up...
"When you use a methyl alcohol based product it soaks up water and prevents freezing. The problem is although the water and alcohol mix, that mixture won't combine with the gas so it stays in the tank causing long-term damage. ... To actually protect fuel system parts the water and alcohol have to get out of the tank."
Are you using it a a fuel stabilizer? I use Sta-Bil brand in my machines, never had any problems.
I also was curious about the meth in the tank. So I also googled the freezing point of gasoline... -40 degrees. Which I almost think that number was pulled out of a hat being that's the one temp that coincides on two of the most used temperature scales. Regardless, I don't think I've ever seen frozen gasoline. I've seen diesel gel up though.
Methanol and Ethanol are marketted as HEET are gasoline additives to aid cold weather starting. The methanol works better for me. The methyl alcohol is denser than water, so it goes to the bottom of the tank, and combines with water/ice. Then the gets pulled through the gas lines are burns up in the engine. Anyway , that's what the advertisements say.
I think that adding methanol or HEET to the gas makes it more likely to combust with the spark plugs' spark.
So the original question was, is wide opening throttle starting in cold weather normal? What is going on?
The freezing point of gasoline may be -40F, but the freezing point of water will always be 32F (or 0C). The methyl-alcohol being used in the fuel tanks under such conditions combines with whatever water may be in the tank because alcohol (ethyl or methyl) is readily soluble in water - as any Scotch whisky drinker can attest. The alcohol bonds with the water to prevent the creation of ice crystals in your gas tank, which won't flow through the pick-up screen, the filter, or the pump and fuel injectors (EFI cars). Think of it like adding anti-freeze to the water in your gas tank.
Additionally, whatever water content may be in the tank even when bonded with alcohol molecules will allow easier re-freezing when it's drawn through the Venturi of your carbeurator throats. The nature of a Venturi design is a decreased pressure due to increased velocity, and that reduction in pressure is enough to cause carbeurator icing - literally ice forming in the carbeurator throats which prevent the flow of air. Here, the HEET helps to keep the water in solution so the carb doesn't get a glut of it on cold start. With water being more dense than gasoline (...as water weights 9.6 lbs/gallon and gasoline only 6.7 lbs/gallon), that water would pool at the bottom of the tank and be drawn into the system first. This is why airplanes have fuel drains at the bottom of the tank, which are drained out before every flight to check for and remove any water content before take-off.
Point being, if you were certain there was no water in your gas tank, you wouldn't need to add anything to ensure proper super cold weather start performance. In fact, at extremely cold air temps (less than -40F), there's not enough heat in the air to contain any water as condensation and it immediately falls out as ice crystals, i.e. snow.
So the original question was, is wide opening throttle starting in cold weather normal? What is going on? The open throttle condition causes high enough manifold vacuum to pull the gasoline (ice and all) out of the jet nozzle discharge tube.
Well, understanding some of the chemistry and physics behind it says you may have answered your own question. On your car, you may need to hold the accelerator pedal all the way down to get it to start when it's really cold out. On my car (13b EFI), I press the pedal to the floor once and then let it up - and it starts every time; but cold for me is only down to ~35F, whereas cold for you could be sub-arctic.
Point being - every car and driver is different as to getting their car started. On a 1963 C2 Corvette roadster, I have to pump it twice and then hold the throttle halfway open when I crank it - and that's on a beautiful fall day of 80F and clear skies.
If you have to hold the throttle completely open for it to start, I guess that works for you, so it's normal,
