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I supported Toymods
Location:
Sydney
Registered:
September 2003
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 Water vs Carbon Buildup drama
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Tue, 24 February 2004 09:16
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Hi, this is the story:
4ac AE82, running fine & dandy, but 'runs-on'/'diesels' on hot days.
Brand new spark plugs, all happy.
To kill the run-on, i sprayed, then got impatient & slowly poured, no more than ~300mls of filtered water down the guts of said 4ac the other day to 'steam clean'.
Revs were held up above 2000rpm, but obviously dropped with all the stuttering going on. No steam, or noticeable black shite ejected.
The only obvious result was a constant miss giving an idle kicking between 600-1500rpm. woohoo!  Keeps missing throughout rev range.
Car has done maybe 200km since, no change. Tried the hair of the dog just now, another 300mls or so of water, no change. Plugs & leads are connected ok.
The funny thing is that 1st thing this morning i think it was idling ok on cold idle. but then i was about 12% awake, so that's not certain.
Any diagnosis or suggestions other than buy a GZE/sprinter/celica/supra would be very welcome!!
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I supported Toymods
Location:
Sydney
Registered:
September 2003
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Re: Water vs Carbon Buildup drama
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Tue, 24 February 2004 23:58
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bump!
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I supported Toymods
Location:
Perth, Western Australia
Registered:
December 2002
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Re: Water vs Carbon Buildup drama
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Wed, 25 February 2004 00:27
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Yep, I have done this a couple of times, it either works brillantly leaving a big black carbon patch on the driveway, or nothing at all. A recent conversation with a knowledable fellow, resulted in his warning that doing this to older engines could dislodge "chunks" of carbon leading to all matter of problems. I'd suggest the missing and pulsing is due to an altered setting in the carby, look yourself and then if you still can't find the problem, take it to a carby specialist, as I know these cars have inherent carb problems, which take a variety of costs to fix. Should you wish, you could also try purging the carby, by reving it up to 4-5000rpm then quickly placing a rag over the inlet, until the revs die, then releasling while still running, though I doubt this will solve your problem.
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I supported Toymods
Location:
Sydney
Registered:
September 2003
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Re: Water vs Carbon Buildup drama
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Wed, 25 February 2004 01:07
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cheers, ill have a look around
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Location:
Menai area of Sydney
Registered:
June 2003
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Re: Water vs Carbon Buildup drama
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Wed, 25 February 2004 03:26
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Have similar trouble sometimes on with a 4AFC. Have noticed that when using Synergy 8000 I don't get the problem and my idle is more stable at other times. I know it's supposed to be higher octane than the 4A needs but I have fixed the run-on problem several times by filling up with Synergi 8000, especially in the recent heatwaves we've been having. Try some good quality fuel so you have a higher flash point and hopefully less dieseling.
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I supported Toymods
Location:
Sydney
Registered:
September 2003
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 Blocked idle jet?
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Sun, 29 February 2004 04:59
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Well, 1/2 a tank of optimax and stacks of carby cleaner later things are improving. I have 'skooled up' on carbies, so this is my theory - how's it sound?
With throttle applied, whatever temp, everything is cool.
Warm: choke open, so with no throttle only idle jet is supplying fuel, this is partially blocked, so car runs rough as guts.
Cold: No throttle, choke closed, fuel is being sucked from big main and small idle jets, so partial blockage of idle jet not noticeable therefore fast idle no worries.
So I reckon my steam clean did nothing but spat some crap into the idle jet of the carb.
So the question is: apart from more optimax/spray/additives, can i get to the idle jet without taking the carb off the engine?
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Club Member
Location:
sydney
Registered:
May 2002
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I supported Toymods
Location:
sydney.au
Registered:
August 2002
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Re: Blocked idle jet?
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Sun, 29 February 2004 06:44
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| IRA11Y wrote on Sun, 29 February 2004 17:35 |
an easier way.. buy and adapter plate and a 36/36IDF weber from and alfa wrecker and go have some fun.
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ZING!
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