pjburges

So a female friend of mine managed to put in an entire tank of E85 into her Miata and drive it from Waco to Austin running quite badly....

It would throw the check engine light and lean misfire (though I wasn't there to see it.) She would drop it into 4th and ride the clutch a little to keep it going down the highway!! Wow. Now that she made it home, next weekend I committed to helping her get the methanol out / dilute with gasoline.

My question to all you other gearheads is - what type of damage should I be looking for? Obviously must have ran hotter lean ,so should I give it a compression check and see if its got burnt (leaking) valves? I'm going to replace the fuel filter because its a 1991 and I'm imagining its never been replaced, and the E85 might have loosened up a lot of gunk in the tank.

Will it ruin all the fuel lines too? Anyone got some 944 experience with running alcohol based fuels?

Thanks for any help you can give me!

AScholtes

You will want to do a compression and leak down test. Also check the plugs. Ethanol isnt going to hurt the lines from just one E85 exposure. Gasoline has ethanol mixed in, so modern cars are designed with this in mind.

I would say that if she didnt cook the head from the way hot exhaust temps she is lucky. That thing was probably running 17-18 or better:1

944Ross

The list of things it COULD screw up is pretty extensive....fuel pump, tank, level sender, hoses, FPR, etc. One exposure probably won't do much, but the sooner you get it completely out of there, the better. I wouldn't wait til next weekend to drain it. Oil change may be in order too.

krystar

yea i'd check head first. compression and leakdown if u can. obviously clutch is prob almost dead.

onspeed

women...

good to see another Austin'er.

944V8inDFW

Only problem i have seen with E85 is a melted converter as the engine thinks it is running lean and keeps pouring in fuel, thus super heating the cat and often times melting it.

pjburges

944Ross - I see you own a 51 Ford F1 - You wouldn't be interested in an original 52 Ford F2 would you? I've got a running one that just needs a resto and rust kill thats served duty as a farm truck for years.

On this Miata - I'll give it a compression test. A leakdown is kind of a pain in the butt although I have the gauges. I think I'll know right away from the Comp test without the extra data the leakdown gives you. If those valves are burnt / warped they'll be varying quite a bit cylinder to cylinder. I'll check and probably have to replace the plugs. Pray there aren't any holed pistons. And I'll change out the fuel filter / purge the fuel system. If the cat burnt out the EPA can kiss my butt. Just as long as it still flows!

And to think - I wanted to date this girl because she was pretty darned good at driving a stick shift (no puns intended)! Now...I don't know what to think. She's certainly a driver...NOT a mechanic! LOL

Thanks for the help ya'll!

944V8inDFW

Biggest problem with cats that melt is they rarely melt and leave a hole, they normally melt closed.

And depending on the hotness of the girl will equal how much work you do!

Dougs951

Pics will determine the appropriate course of action.

xschop

I like the quote I saw on the 928 board recently....Something like the Porsche is like a hot chic, you gotta dump alot of money on her before she performs....something like that.
F a cat and FCARB....
The majority of Americans that drive 10-15 minutes to work won't get a complete burn-off of uncombusted HC's from the cat anyways, what a joke.

toddk911

Check out the 944T specific forums. There are numerous members running E85 and all swear by it for modded/higher boost. Just have to richen the mixture about 20%, but it is considered about 105 octane or so. Also, none that use it for long periods have experienced any of the "wives tales" that many think. No problems with fuel lines, or components, etc.

I am not sure of the computer system of a Miata, but if it is pretty new, it might have picked up on the leaness and riched it up and/or pulled some timing or both.

Based on your description of how it ran I say it pulled a lot of timing out. So it should be ok.

944V8inDFW

must have pictures

running_cold924

atleast she didn't break down along side of the road....at work we had an old dodge RV towed in because the old guy put in diesel instead of gas....OOPS! his 20 gallons worth of diesel cost him almost &700 to get rid of. (half being the charge to safely get rid of the diesel fuel)

JohnKoaWood

Only problem I have with burning cats, is making sure they run away from you, and not under a car!

n_hall

we had a sprinter towed because someone put gas instead of diesel. they guy that did it didn't pay anything for his mistake though. but it made for a good story when it happened