Things to check? Running rich + Backfire

[pwjm]

EA81 hatch, it's been a little harder on gas lately, and is backfiring between shifts and when decelerating. Usually just a quiet Put put put on decel, and occasionally a moderate POP between shifts... although it can sound like a gun shot If I Floor it from the bottom of the gear.

 

I looked over the vac lines a little bit and they all seem attached properly, didn't look to hard for cracks though.

 

The exhaust smells very rich as well.

 

this is the first carbed vehicle I've ever had, so I just need some advice on where to start looking for problems.

[corvette6698512]

The choke could be malfunctioning. Does it run good when its cold and get worst as it warms up?

[Loyale 2.7 Turbo]

Seems like the Carburetor got Dirty, I Kindly Suggest you to Clean it and it could be done in Two Ways, the Easy and the Hard way.

 

Easy Way is for Light Dirt:

 

- Get a "Carburetor & Choke Cleaner" Spray.

 

- Run the Engine 'till it Raises to Normal operatin' Temp, then Shut it Off.

 

- Then unhook and Remove the Air Filter Box.

 

- Use the "Carburetor & Choke Cleaner" Spray and Gently Spray first the Carb's Outside Movin' Parts and then the inside, while manually move the Butterflies and Choke; then Carefully insert the mini Straw in the Spray can's tip (be careful to avoid Spray yourself) and try to Reach with the Sprayed Cleaner the internal Parts.

 

- let it Rest for a while, (one Hour minimum) then try to Start the Engine with Gas Pedal between 1/4 to 1/2 of its way Down; dont pump it to Avoid Drowning. The Car will be Hard to Start but after three or so Tries it Shall Start, first very Rough... Let the gas pedal Li'l Pressed and let it Stabilize itself while you still have the Gas Pedal Li'l Pressed.

 

- Finally with Engine Runnin' at normal Idle Speed and completely Stabilized, take the Spray can again and Remove the mini Straw, manually Hold the Accelerator Cable and accelerate the engine at around the 4,000 RPM's and Hold it There while you give to the Carb's Throat Short (two seconds Long) Sprays of Cleaner... The engine will reduce the RPM's but you Must Keep Holding the cable at the same position and let the engine Back to the 4,000 RPM's acceleration and Stabilize itself back again ...

 

- Repeat the Short Spray again while you still keep holding the accelerator cable ... do That for ten or so Times, then Keep Accelerated the Engine untill it Stabilizes itself again, finally when is Stabilized, release the Accelerator Cable and let it Rest at Idle RPM's for a While.

 

- Final Step: Test Drive the Car, the Problem Must be Gone.

 

- Advice: After done that Carb Cleanin' Procedure, I Kindly Suggest to Change Sparkplugs, air Filter and Gas Filter as Needed if those are Old, also is Very important to add a Gasoline additive "Carb & Fuel Injector Cleaner" to 3/4 Gas Tank and Drive the car without Refill the Tank untill Near Empty.

 

There is a Chance that the Distribuitor's Points are gone Bad too, so I Kindly Suggest you to Change 'em.

 

Warning!: Wash your Hands and avoid to Spray the Cleaner to the Skin or Eyes, is very irritating.

 

 

Hard Way is for Very Dirty Carbs or when the Easy Way Failed:

 

in That Case Take the Carb to a Qualified Carburetors Service Shop... or get Rid of that Hitachi Crapburetor and Swap there a Weber! for Better Performance, Easy Maintenance and increased Lower end Torque... also Better (Cleaner) Engine's Look.

 

I Hope this will Help you!

Kind Regards.

Edited December 24, 2009 by Loyale 2.7 Turbo
to add the Warning!