QuestionBrandon, I agree,lazy. I have to find an old school tech who does not need a code to diagnos. If an injector is stuck open, would a fuel injection cleaning fix it? Also, would a malfunctioning thermostat have an effect on mpg, rough idle? Might be a dumb? thought I'd ask.
Thx, John
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Brandon, I fogot to tell you it's 1990 Celica. Maybe why no check engine light? It truly is running really rich. Would you take it in for a fuel inject clean? What other test would you ask the tech so i don't waste his time and my $ hunting around? They really can't run diag because codes to old? Compression check reveal anything? I'm running out of garage working weather(Wisconsin).
Thx again, John
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Hi Brandon, Can a cat converter disintegrate over time(16 yrs) without many miles on it and have an effect on mpg? I just bought a celica with only 75k on it. I'm only getting 15mpg cty and the exhaust is extremly rich. At acceleration it bunny hops then pans out. It idles rough at 750 rpm in gear. No check engine light. I put in new plugs,cap, o2 sensor, cleaned throttle body, air filter, fuel injector cleaner, checked throttle position sensor to specs. Took it to Toy dealer for diag. said nothing wrong. B.S. Wasted $80. Could it be the vapor cannister($$$)?
Thx, John
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Take the cat off & see. Or have someone weld in a pressure tester. If a cat clogs the performance will completely tank. It would be like you trying to exhale through a straw, times a hundred.
Na, the EVAP canisters go bad every so often, but they won't affect it like that. You won't notice a differance when they go. it'll just trigger a check engine light.
Sounds more like an injector is stuck open to me, but it's alittle odd you've not thrown a check engine light for running too rich if it's as rich as you say, or a check engine light for a misfiring plug, letting that cylinders fuel dump striaghtinto the exhaust.
btw only use NGK, or Denso plugs & you can't "clean" a fuel injector, unless you take it off & send it somewhere. Technically you can, but no dealer, or mechanic is going to actually take one off & clean it, then test it's flow by hand. It takes way too long & is unproductive. Something like a mechanic would do to his own car on a weekend to try to save some money, or a racer would to do to even out the injector flows.
Nice cleaning the throttlebody & the TPS sensor. Clean the idle & EGR valves if equipped, and you've got maintenance 101 nailed to a wall.
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That'll explain that.
Probably a fuel injector stuck open.
They can run diagnostic, they're just lazy. It only takes a multi-meter. :) The old system isn't terrible, or impossible to work with. It's simply abit simplistic & you do most things manually via one of the two/three DIAGNOSTIC ports on the car.
AnswerTe thermostat wouldn't much. They do a tiny bit becuase the car won't go into open loop until warm, but don't worry about that right now. ;)
Sometimes cleaning works, sometimes it doesn't & they need a rebuild. It depends on the injectors! Pretty much everyone online doing aftermarket/hi-po installes use RC Engineering to clean their stuff up.
http://www.rceng.com/
http://www.celicatech.com/imagearchive/bgbonline/bgb.php#5th
Has afew of the factory service manuals for Celica's.
