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ZUKIWORLD Discussion Forum => Technical Discussion - Performance / Modify => Topic started by: faskenr on December 24, 2011, 07:54:57 AM

Title: Tuning a 1990 1.3Lt Carburated Engine
Post by: faskenr on December 24, 2011, 07:54:57 AM
Hello,

I have a 1990 Suzuki Samurai 1.3 Lt, and I have trouble with cold starts because it idles too fast and over-speeds the engine.  It has a mikuni carburator. Does anyone have suggestions on how to reduce the idle speed?  Thanks everyone.
Title: Re: Tuning a 1990 1.3Lt Carburated Engine
Post by: fordem on December 24, 2011, 03:28:44 PM
Gasolene engines are designed to idle at a "higher than normal" speed when cold to reduce the possibility of them stalling - how fast does yours idle?  I'd say around 1800 rpm when started and then dropping slowly as the engine warms is normal.

Depending on what carburettor you have, there may be a "fast" or "cold" idle adjustment - or if you have the Hitachi electronic feedback carb, I believe a vacuum leak can also cause it to idle fast.
Title: Re: Tuning a 1990 1.3Lt Carburated Engine
Post by: Skyhiranger on December 24, 2011, 06:03:26 PM
Hello,

I have a 1990 Suzuki Samurai 1.3 Lt, and I have trouble with cold starts because it idles too fast and over-speeds the engine.  Does anyone have suggestions on how to reduce the idle speed?  Thanks everyone.

Are you sure yours is carbed?  A 1990 samurai had an EFI 1.3 from the factory.  The EFI samurais are known for excessively high cold idle.  The "fix" is to remove the plate on the front of the throttle body that has 3 screws in it and turn the disc on the inside that has a bunch of nubs around its perimeter and it will lower the cold idle.  I believe you turn it clockwise, to lower the idle, if I remember correctly.