UNIQUE fuel problem

Discussion in 'Trucks and Trailers' started by steveair, Mar 12, 2000.

  1. steveair

    steveair LawnSite Bronze Member
    Messages: 1,073

    Hello all,<p>I have a unique fuel situation and was just looking for some comments on the whole matter. <p>Where I work, an airport, we have 100 LL (100 octane low-lead) fuel that prop planes burn. Everday, they sump the tanks so we get extra, and myself and the maintenance crew have been burning it in our cars. <p>My question is whether or not this is any good. From what I've heard, the main problem is it burns hot and produces a white like ash that coats the plugs and cylinders. Also, it clogs up your catalytic converter a a bit faster. <p>Some guys have been burning it for years now and say they never had any real problems besides having to change plugs and getting a new cat. They mainly have big V8s. The savings, as you can figure, are great for us. With the cost of fuel as it is, even if you have to change plugs and cat, the overall cost is far less than buying regular. <p>Currently, i burn nothing but 100ll in my 90 dodge 350 with a 360, and have had no problems. It doesn't run great, but it runs good enough for me, or should i say good enough for free. Also, I tried it in my 99 somoma, a little 2.2 l four, and ran into some problems. Now the service engine light is on and won't go off. I was wondering if it is just the computer picking up a emission problem and whether it really means anything. That stupid light comes on when the gas cap insn't tight, so i really question if it is a concern or not. Its still under warranty, so I figured if it is a problem I'll take it to the dealer and they will fix it, because I'm sure they have no way of telling wwhat I was burning....<p>Any comments appreciated<p>Steveair<p><p>
  2. Abe

    Abe LawnSite Member
    Messages: 98

    Well here is what I know<p>forget about the catalytic converters as 1 tank will burn it out with the leaded fuel even though it is a low lead fuel. burning 100 octane can burn your valves and cause other problems, especially in smaller engines.<p>If you are getting the fuel for free,, I would recommend spending a few bucks so that you are burning 1/4 tank of the low octane fuel the mix will give you a low to mid 90's octane and will probably help with the number of plugs you are burning and make your vehicle run a bit better<p>as for running it in the 99 sonoma,,,,,, replace the fuel with the 89 octane and take it to the dealer, should still be under warranty and let them figure out what the problem is and fix it..... and I wouldnt run that high octane fuel in such a new vehicle<p>-abe<br>
  3. CA Enterprises

    CA Enterprises LawnSite Member
    Messages: 82

    Interesting!!!! My father is a semi-retired pilot and is managing the local airport at home. The only people I have ever heard of or seen running 100ll is racing their vehicles. I would assume the reason you v-8 doesn't have much problem is that it runs a little hotter anyway. I like the idea of mixing the lower octane fuels with the 100ll to produce a lower octane level.<p>The lead probably got to the oxygen sensor on the Sonoma and this is a possible cause for the engine light. Let the dealer figure it out if it's under warranty. Don't tell them you put 100ll in it!!<p>Maybe just swith the engines with an old Cessena that ready for TBO---lol!<p>Adam:)
  4. John DiMartino

    John DiMartino LawnSite Silver Member
    Messages: 2,555

    I agree,Oxygen sensor is gone.The 99 is OBD-2.That means it finds and knows how to tell what you did to a point.It has 2 oxygen sensors,one before the cat-and one after.So you cant gut the cat-it will store a hard code and run so bad you'll need to get it fixed.It will need a new cat,2 new sensors,it is covered under emissions warranty.I wouldnt try it again,they will know your up to something if it happens again.Get all the fuel out before you bring it in,and the residue in the motor still might fry the new sensors.If you must use this fuel use it in 1995 or older cars/trucks.They are OBD1 and will run with a gutted cat and a fouled oxygen sensor,although not as good if the sensor was OK.It will get bad gas mileage with fouled sensor.I always thought(I may be wrong)that higher octane fuel burns cooler and is harder to ignite,more stable at high pressures in a combustion chamber.That is why it will burn in high compression engines without pre-ignition,and low octane starts to burn before the spark plug lights it,any hot spot will get it started,giving you the knock and low power,I have some snowmobile pistons in my garage that are victims of this along with my wallet.I think you will not hurt the engines at all,in fact they should run cooler and you can advance the timing for more power if its the only fuel you use.Good luck at dealership.<p>----------<br>John D<br>
  5. steveair

    steveair LawnSite Bronze Member
    Messages: 1,073

    Well, I thank all of you greatly for the information. I had a feeling it was the sensor in the sonoma, so off too the dealer I go....I usually mixed the gas half and half with regular in the small engine, but being cheap and tempted by free gas, especially with the prices today, I guess I burned a little too much in it. The sonoma still runs good now though, but I'm interested in hearing what the dealer says........Hope it is good. The truck has 28000 on it in less than one year, so it may not seem like that out of the ordanary problem to them. As the for the dodge, I really could care less what happens. I bought the truck last year for 3000 and save over 60 a week in fuel. In another couple months, Ill have saved the cost of the truck in fuel alone! <p><br>
  6. CA Enterprises

    CA Enterprises LawnSite Member
    Messages: 82

    Hey, <p>Let us know what happens at the dealership. Will be interesting to see if they figure it out. I doubt unless they tear the engine apart!!!<p>LOL Adam :)
  7. yortengel

    yortengel LawnSite Member
    Messages: 216

    Well I recommend that you take the S-truck to the dealer and let them fix it under warranty, they won't be able to tell what type of fuel was in it as long as you have run a couple of tanks of regular N0-Lead. I ran a hole tank of 100LL though my 84 K20, It ran the same. I didn't notice any real difference, I did notice that the exhaust smelled like the C175 that I fly. If i were you I'd reajust the timing on the dodge. should really run good. the O2 sensor may be done. Its a shame you cant reprogram the SBEC to adjust Air/Fuel by map only. you might try unpluging the O2. the SBEC may install a fixed value for the O2. I'll see if I can find some info at work on it, I'll get back to you. I can't remember that far back.

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