Hesitation at middle RPM under moderate load
in [Technical]
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From: Ray O on 24 Jul 2010 00:47 "Scott Dorsey" <kludge(a)panix.com> wrote in message news:i2c42f$2ga$1(a)panix2.panix.com... > Ray O <rokigawa(a)NOSPAMtristarassociates.com> wrote: >> >>I second the carbon buildup on the valves. Hook up a vacuum gauge, and >>when >>the problem is occurring, see if vacuum drops. If the Techron doesn't >>work, >>find a shop with Motor-Vac or that has a way to do the walnut shell blast. > > The original poster mentioned using high-test gasoline in it just because > it was cheap right now. > > If you run enough high-test in an engine designed with fairly low > compression, > you're apt to wind up with carbon deposits as a result. > --scott > -- Good point. Use what the owner's manual says to use. -- Ray O (correct punctuation to reply)
From: Clive on 24 Jul 2010 07:10 In message <i2drad$pc7$1(a)news.eternal-september.org>, Ray O <rokigawa(a)NOSPAMtristarassociates.com> writes >"Scott Dorsey" <kludge(a)panix.com> wrote in message >news:i2c42f$2ga$1(a)panix2.panix.com... >> Ray O <rokigawa(a)NOSPAMtristarassociates.com> wrote: >>>I second the carbon buildup on the valves. Hook up a vacuum gauge, and >>>when >>>the problem is occurring, see if vacuum drops. If the Techron doesn't >>>work, >>>find a shop with Motor-Vac or that has a way to do the walnut shell blast. >> The original poster mentioned using high-test gasoline in it just because >> it was cheap right now. >> If you run enough high-test in an engine designed with fairly low >> compression, >> you're apt to wind up with carbon deposits as a result. >> --scott >Good point. Use what the owner's manual says to use. Over here, we only get one Petrol and that's about 95 RON. De-coking, or you might call it decarbonising is now very rare with today's modern fuels, 50 years ago a de-coke might have been performed ever 20k or so but with the detergents now in fuel a good blast down the motorway normally cleans out any muck that might have accumulated during light start stop, idling type of driving. -- Clive
From: Ray O on 24 Jul 2010 09:56 "Clive" <clive(a)yewbank.demon.co.uk> wrote in message news:XkaPZWE1osSMFwaA(a)yewbank.demon.co.uk... > In message <i2drad$pc7$1(a)news.eternal-september.org>, Ray O > <rokigawa(a)NOSPAMtristarassociates.com> writes >>"Scott Dorsey" <kludge(a)panix.com> wrote in message >>news:i2c42f$2ga$1(a)panix2.panix.com... >>> Ray O <rokigawa(a)NOSPAMtristarassociates.com> wrote: >>>>I second the carbon buildup on the valves. Hook up a vacuum gauge, and >>>>when >>>>the problem is occurring, see if vacuum drops. If the Techron doesn't >>>>work, >>>>find a shop with Motor-Vac or that has a way to do the walnut shell >>>>blast. >>> The original poster mentioned using high-test gasoline in it just >>> because >>> it was cheap right now. >>> If you run enough high-test in an engine designed with fairly low >>> compression, >>> you're apt to wind up with carbon deposits as a result. >>> --scott >>Good point. Use what the owner's manual says to use. > Over here, we only get one Petrol and that's about 95 RON. De-coking, or > you might call it decarbonising is now very rare with today's modern > fuels, 50 years ago a de-coke might have been performed ever 20k or so but > with the detergents now in fuel a good blast down the motorway normally > cleans out any muck that might have accumulated during light start stop, > idling type of driving. > -- > Clive > I have not run across valves with deposits in a long time - I suppose that the fuel additives actually work! -- Ray O (correct punctuation to reply)
From: Hachiroku ハチロク on 24 Jul 2010 11:38 On Sat, 24 Jul 2010 12:10:45 +0100, Clive wrote: > In message <i2drad$pc7$1(a)news.eternal-september.org>, Ray O > <rokigawa(a)NOSPAMtristarassociates.com> writes >>"Scott Dorsey" <kludge(a)panix.com> wrote in message >>news:i2c42f$2ga$1(a)panix2.panix.com... >>> Ray O <rokigawa(a)NOSPAMtristarassociates.com> wrote: >>>>I second the carbon buildup on the valves. Hook up a vacuum gauge, and >>>>when >>>>the problem is occurring, see if vacuum drops. If the Techron doesn't >>>>work, >>>>find a shop with Motor-Vac or that has a way to do the walnut shell blast. >>> The original poster mentioned using high-test gasoline in it just because >>> it was cheap right now. >>> If you run enough high-test in an engine designed with fairly low >>> compression, >>> you're apt to wind up with carbon deposits as a result. >>> --scott >>Good point. Use what the owner's manual says to use. > Over here, we only get one Petrol and that's about 95 RON. De-coking, > or you might call it decarbonising is now very rare with today's modern > fuels, 50 years ago a de-coke might have been performed ever 20k or so > but with the detergents now in fuel a good blast down the motorway > normally cleans out any muck that might have accumulated during light > start stop, idling type of driving. I used to have one of these back in the 70's http://hem.passagen.se/bubben0205/bilder/1800es.jpg A "good blast down the motorway" was required about every 7-10 days. Going up through the gears, by the time you hit 4th at ~65MPH all of a sudden the car would start to stumble, and then WHAM! Off to the races.
From: Scott Dorsey on 24 Jul 2010 12:07
=?iso-2022-jp?q?Hachiroku_=1B$B%O%A%m%=2F=1B=28B?= <Trueno(a)e86.GTS> wrote: > >This car ran the best on mid-grade. The next fill up I am going to fill it >with mid grade. I did so much running the last couple days it's at about a >quarter tank now... If the engine is designed to run on regular, but it runs better on the mid-grade now, that's another sign of heavy carbon buildup. The actual combustion area has become smaller because of the carbon packed on the piston. >And another bottle of Techron. I don't know how much good that stuff really does, but it won't hurt. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |