Finally smooth idle!

I have been slowly replacing parts and fine tuning my 1988 Lucas V12 for the last 2 years and have achieved what i would say a very smooth idle most of the time.

But it was not 100%, sometimes a bit off when cold, or the odd hiccup now and then.

I may have found what seems to finally bring the idle to 99.9%
smooth?! Marvel Mystery Oil in the fuel. I added about 5oz per 10 gallons on last fill up. Not sure what its doing, perhaps it is helping treat our modern ethanol gas which our cars weren’t exactly designed for? Or it’s just helping smooth out the injectors? Or ?

I have no affiliation with MMO, but at $0.25 per ounce cost (if i buy gallon for $32), i think I’ll continue!

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I guess you’ll have drive around with MMO and a measuring cup in the trunk of your car from now on URGH!!

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I’ll do it until i use up the 128oz I bought. Then go back to none, and see what happens. Maybe I just need some of it’s cleaning properties to run the course.

I fill up every two weeks about 12 gallons.

128oz / 5oz= 25 fill ups

Thats a whole year!!! Wow

Do you not run Shell Gold or premium? I never run gas in the V-12 with ethanol. Ethanol is hydroscopic and will separate the water and rust your tank and clog your fuel filters , pumps etc… Not to mention it doesn’t have great shelf life and you’ll burn more at fill up time since it doesn’t have the same combustion as real gas.
I’ll run some Lucas injector cleaner ( no affiliation ) through once in a while as it’s lubricated as well.

Yeah, I run non ethanol gas in all of my vehicles as well. I can only get 90 octane from my local station, though. I also get my diesel there as well, it’s not not diluted with the 15ppm sulfur. When I’m traveling I usually try and hunt those types of fuel stations down, even if it means going out of my way, doesn’t always work out, but I try my best.

I do run 92 octane premium, usually Chevron. But it contains ethanol here in the US. Not sure where i can go for non-ethanol. The MMO supposedly helps with water.

Looks like a boat place near by sells it…but $4.80/gallon for super?!

I thought as long as your gas doesn’t sit too long (weeks of non use) ethanol is ok. And adding StaBil if it does sit.

From my travels it seems that the farther west you go the less likely it is to find pure gas. Those stations seem to be more prevalent in the Midwest as I think about it.

For a small amount of petrol here is one way of getting non ethanol gas. Not really feasible for large volumes.

No affiliation but have you used this it’s an enzyme treatment, sort of big in the motorcycle and boat world. I run it through my other vehicles to deal with the water ethanol separation issues. Usually makes easier starting , smoother idling , will even turn out the ‘“check engine light”, especially in this part of the world with temperature changes during winter where condensation can be a big issue

Interesting. But I think just siphoning or squeeze pumping the water out would work just well as creating the upside down bottle rig.

Agreed, some people just like to make it difficult.

I just don’t want to offend anyone, but as these cars get older , I just don’t believe ethanol gas will do anything but harm your car. Seals , water in your tank, rust issues, stale dated between one and three months, lousy gas mileage etc, etc , etc ??? If anyone believes they are driving a classic Jaguar and want to save themselves a ton of issues down the road, then I would just suggest buying real premium gas. My two cents, and no I’m in no means a petro chemical scientist who works for the big oil companies who want to sell a lesser product for the masses in the name of the environment.

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Eh. I’ve been driving my car for at least five years. Daily driver. I fill up once a week. Ethanol is all I can get.

I just popped a camera in my gas tank. Couldn’t be cleaner. No leaks. Maybe the tanks before Ford came on the scene fare worse, perhaps it’s only the cars that get driven occasionally….I haven’t had any issues with seals or rust, or anything else fuel related for that matter. I use Top Tier fuels, like Shell, and I stick to the Premium pumps, but unfortunately, they’re all ethanol.

Like I say don’t want to offend anyone but the Shell top premium fuel they sell I’m my neck of the woods is (I believe) the only fuel sold that does not have an ethanol content. I also understand that ethanol will actually make you spend more money on gas as it won’t get you the same miles per gallon. Don’t shoot the messenger. 30 year old cars or older ,I don’t believe ,were ever designed for burning ethanol fuel. We just had a neighbourhood bulletin where some poor chap bought ethanol fuel and noted even as he pumped it he had a sour gas smell . The shelf life is anything from one to three months. It is hydroscopic and separates water, plus varnishing of components. Other wise why did the big three auto makers put those nice flex fuel stickers on the back of the vehicle if all gas was created equal.
As my daughter would tell me just seyin?

Not arguing with anything you are saying, just sayin that the 96 model with the AJ16 engine seems fine if you’re using it regularly.

Garage queens may experience more of the problems you’ve mentioned.

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Flex fuel refers to E85, which is 85% ethanol- vehicles capable of using it have stainless steel fuel system components and higher flow injectors/electronics to deal with the necessary increase in fuel flow when E85 is used.
In the US, the governing agencies allow up to 15% ethanol in gasoline, which the fuel systems in most vehicles can handle, the additional flow rate being less than 10%
I think the problems start when vehicles have other existing issues or are not driven frequently. I have no issues, mine is a daily driver. Just my .02

I agree , I was originally referring to the post from Gregma who was saying that that he was using MMO in his gas to get a smooth idle for his V-12.
I must admit I have used gas with up to 10% ethanol when needed out in smaller communities as it seems to be more the norm these days. I just try to avoid it whenever I can.

Yes you are correct, by the way I do use regular fuel in all my other three vehicles, but they’re likely better equipped than a V-12 designed 60 years ago with all that perishable British rubber components.

I have a 2010 chevy express van 6.0 i just got has 328000 miles on it it was a fleet truck well maintained, it says flex fuel on the back so i filled it with flex never again runs like crap ,you have to run it for about 10 minutes in the morning before you go anywhere and the mileage is down, ill stick with reg.gas. in my jag i only run sunoco 94 octane.

Where do you get it that cheap, Gregmatic? :confused: My ex tech bud used to swear by that stuff (like another friend of mine does for that “Sea Foam” product), but knowing his rep with me I was afraid to let him put it in any of my Jags. :grimacing: :laughing: