Misfires on ethanol in winter

bbeem

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This question is for everyone on ethanol tune. It's now 20f-30f days in Iowa, colder at night so I've went down from 35% ethanol to 25%. I'm planning on about 10% next week and through the winter. The fuel is probably 20*f and my IAT is like 45f.

Anyway Ive been getting tons of misfires if WOT between 5k to redline this weekend. I was in Mexico for the week and came back to the freeze, drove the car easy for 45 mins then when I started wot twards redline TONS of misfires. Ethanol in the freeze I hope? Shouldn't be that bad though. I'll put new plugs in at noon tomorrow?

Last time I got misfires at redline was also last winter, when my head gasket leaked between cylinders. It's stupid thin with a coolant channel between each cylinder on the gasket. Sucks.
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This question is for everyone on ethanol tune. It's now 20f-30f days in Iowa, colder at night so I've went down from 35% ethanol to 25%. I'm planning on about 10% next week and through the winter. The fuel is probably 20*f and my IAT is like 45f.

Anyway Ive been getting tons of misfires if WOT between 5k to redline this weekend. I was in Mexico for the week and came back to the freeze, drove the car easy for 45 mins then when I started wot twards redline TONS of misfires. Ethanol in the freeze I hope? Shouldn't be that bad though. I'll put new plugs in at noon tomorrow?

Last time I got misfires at redline was also last winter, when my head gasket leaked between cylinders. It's stupid thin with a coolant channel between each cylinder on the gasket. Sucks.
I do not have any personal cold weather experience (not that cold, at least) so I can't recommend much here other than contacting your tuner to see if they have any recommendations. :thumbsup:
 
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bbeem

bbeem

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Its a bit warmer today so I wanted to try again. 40f on the dash. Drove around an hour without shutting off, let idle at the end for 10 mins and got over 100f IAT, then took of for the strip. By then the IATs were back to 70*. Ran 3rd 4th 5th to redline a few times no misfires. So it's very likely the ethanol blend isn't igniting very well below freezing.
 
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bbeem

bbeem

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Pulled the plugs today. Was wet in cyl 3 and 4. Bad head gasket again...
 

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Pulled the plugs today. Was wet in cyl 3 and 4. Bad head gasket again...

Again? How many head gaskets have you gone through?

Kinda scary because I have a 2019 SI. Hoping this isn't a common thing with these cars, that would suck...
 


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What tune are you running? Shouldn't be popping head gaskets every year...

Do the misfires go away on 93 oct?
 
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I am custom tuned running on e36.
Temps went down low 30s in chicago. Car had a slight delay in start. No issues while driving. I havent tried fully WOTing
 
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bbeem

bbeem

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So the head gasket leaks between cylinders again. It seems fine untill WOT at higher rpm then misfires. Also makes a coolant gurgle and exhaust burble at startup. Started 6 weeks ago and just needed to add coolant for the first time, about .8 quart. Replaced head gasket at 20k with oe gasket and oe head bolts. Now at 30k and this time I picked up cosmetic gasket and I'm trying to get head studs but but MAP is sold out of the kit. https://www.maperformance.com/produ...6-20-honda-civic-1-5t-17-20-civic-si-hdax-hsk

The kit is $350, the arp studs should be like 200 so those spacers are like $150. Since they're out of stock I'd just turn my own spacers if I knew the dimensions. @MAPerformance
 

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So the head gasket leaks between cylinders again. It seems fine untill WOT at higher rpm then misfires. Also makes a coolant gurgle and exhaust burble at startup. Started 6 weeks ago and just needed to add coolant for the first time, about .8 quart. Replaced head gasket at 20k with oe gasket and oe head bolts. Now at 30k and this time I picked up cosmetic gasket and I'm trying to get head studs but but MAP is sold out of the kit. https://www.maperformance.com/produ...6-20-honda-civic-1-5t-17-20-civic-si-hdax-hsk

The kit is $350, the arp studs should be like 200 so those spacers are like $150. Since they're out of stock I'd just turn my own spacers if I knew the dimensions. @MAPerformance
I havnt had this issue yet but ive been doing research as I just went flex fuel. It sounds like with flex fuel, the stock head bolts cant support the increased pressure so this is where the gasket leak comes from after some time. Seems like the only solution is arp head studs due to the increased clamp force. Only 2 options now are arp kit using double washers method or buy from map with a custom washer already made (lots of downtime like you said to receive)
 
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bbeem

bbeem

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I havnt had this issue yet but ive been doing research as I just went flex fuel. It sounds like with flex fuel, the stock head bolts cant support the increased pressure so this is where the gasket leak comes from after some time. Seems like the only solution is arp head studs due to the increased clamp force. Only 2 options now are arp kit using double washers method or buy from map with a custom washer already made (lots of downtime like you said to receive)
It's sad it blows so easily. I've been considering custom tune but what's the point if it all ready blows with this much pressure. It's not like this tsp2 tune is bad, locked on to .49k and -2 to 0 ltft, smooth and good just worried about more cylinder pressure.

The cometic gasket is better and the arp studs are no doubt better but one thing I'm considering is sealing off those damn cooling channels in the block between cylinders. I have 1500*f high temp JB weld I'm considering sealing them off with. I'm not concerned with the heat but will this effect coolant flow elsewhere in the motor with these passages blocked? I can't imagine it will impead flow elsewhere because such a small amount could flow through the tiny slots anyway.

can anyone tell me if sealing off those coolant channels that should never have been there will effect coolant flow or sensors anywhere else?
 


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Reducing the ethanol content in your mix in colder temps is a mistake. The colder air gets, the more dense it becomes, and the more oxygen it contains. The car adds more fuel to the mix to hit the target AFR. This makes more power but also increases the risk of detonation/knock. Lowering the ethanol content of your mix is effectively lowering your octane and thus lowering the knock resistance of the fuel. If anything keep your ethanol mix the same for winter, or run a little *more*, not less.
 
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bbeem

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Reducing the ethanol content in your mix in colder temps is a mistake. The colder air gets, the more dense it becomes, and the more oxygen it contains. The car adds more fuel to the mix to hit the target AFR. This makes more power but also increases the risk of detonation/knock. Lowering the ethanol content of your mix is effectively lowering your octane and thus lowering the knock resistance of the fuel. If anything keep your ethanol mix the same for winter, or run a little *more*, not less.
Running lower octane decreases knock resistance but this isn't the problem in the winter. 30* air is like 10% more dense than 80* air. This would equate to about 1.5psi boost difference which is pretty negligible.

The problem with ethanol in cold is not enough vapor pressure for igniting when cold starting. This is why 15% gas is added in summer; for winter blends starting in September, refineries increase RVP from like 7psi to 15psi for gas and your e85 will be about e50 at the pump. Not to mention the water absorbtion is even more a problem in the winter. Some recommend 0 or 10% ethanol in the winter. 35% is a problem starting in sub zero and turns over a long time before ignition. Not to mention the water it's absorbing.
 

KingOfBrussels

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If you're getting all that knock at WOT then I would say you probably *do* need the extra octane, and/or need your tune to be adjusted. Cold starts are also best addressed by tuning to run rich for cold cranking and during warmup.

As you said, the ethanol content is already lower in the winter mix E85. Everything I've seen about running E85 mixes during winter in cold climates (I used to live in Wisconsin) says you need to adjust your tune pretty thoroughly.
 
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bbeem

bbeem

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If you're getting all that knock at WOT then I would say you probably *do* need the extra octane, and/or need your tune to be adjusted. Cold starts are also best addressed by tuning to run rich for cold cranking and during warmup.

As you said, the ethanol content is already lower in the winter mix E85. Everything I've seen about running E85 mixes during winter in cold climates (I used to live in Wisconsin) says you need to adjust your tune pretty thoroughly.
My knock is locked on .49 my ltft is -2 to 0 and I don't have trouble starting. Lol. I have a head gasket leak which isn't effecting my afr or knock and starts fine, though makes a blurble sound startjng.
 

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I saw where you mentioned the head gasket problem. My point is that if you have higher cylinder pressures from some combination of running too lean and/or from not enough octane, that could have contributed to blowing the head gasket. Between winter mix fuel and the cold ambient temperatures it really is best to run a winter specific tune if you're running on corn.
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