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ZUKIWORLD Discussion Forum => Technical Discussion - Beginner / Repair => Topic started by: PhilTGross on December 12, 2011, 05:25:12 PM

Title: 1.3L Samurai runs EXTREMELY rich
Post by: PhilTGross on December 12, 2011, 05:25:12 PM
Hey guys, I am a newb mechanic and I have a problem. My 91 EFI samurai is running very rich. You can smell the gas as it idles and it will actually leave a patch of gas on the ground under the exhaust pipe in the morning. I've also noticed that my gas mileage has gotten worse by about a quarter! Things I have replaced recently are: PCV Valve, Throttle body gasket, Valve cover gasket, plugs, wires, distributer cap and also what I think was an air temp sensor on the intake manifold.

Any help would be GREATLY appreciated.
Title: Re: 1.3L Samurai runs EXTREMELY rich
Post by: Skyhiranger on December 12, 2011, 06:15:34 PM
Fuel pressure regulator might be bad.  ECM could be going bad and causing it to run rich.  O2 sensor might be bad.
Title: Re: 1.3L Samurai runs EXTREMELY rich
Post by: Rhinoman on December 13, 2011, 02:44:24 PM
Things I have replaced recently are: PCV Valve, Throttle body gasket, Valve cover gasket, plugs, wires, distributer cap and also what

Did you gap the plugs before you put them in? Why did you change the sensor and are you sure that the replacement was the correct one?
Title: Re: 1.3L Samurai runs EXTREMELY rich
Post by: PhilTGross on December 13, 2011, 05:09:09 PM
Thanks guys for the replies.

I didn't gap the plugs, reason being that I didnt have the tool and I also thought that the factory gap on the new plugs was close enough (.035"). I figured a couple thou wouldn't make much difference especially because the ones that came out were WAAAAYYY worse (like .050-.060). Was this a stupid idea?

 The sensor I replaced was the Air Charge Temperature Sensor. I replaced it because I thought it might help with some power issues I was having and also the old one had a crack in the sensor.

I was investigating my o2 sensor but I didnt know how to really diagnose it. In the Haynes manual it says to rev your engine to 2000 rpms and the output voltage of the sensor should be .45 V (I think that what said). My problem is that I dont have a tach. and I was just guessing at the rpms. Is there a general rule of thumb with o2's, for example will the voltage increase or decrease with higher rpm?
Title: Re: 1.3L Samurai runs EXTREMELY rich
Post by: ebattleon on December 14, 2011, 12:45:32 PM
Get a copy of the Suzuki's FSM it has everything you need...and the Haynes is a load of crap:(
Title: Re: 1.3L Samurai runs EXTREMELY rich
Post by: 1969dane on December 19, 2011, 03:10:06 PM
 What about your idle air sensor?
Title: Re: 1.3L Samurai runs EXTREMELY rich
Post by: PhilTGross on December 20, 2011, 04:56:41 PM
Im not quite sure what you mean. Where is it located and how would it affect the fuel air mixture?