[zookster666]

My g16a in my Sierra is backfiring on deceleration it runs a Sierra head and carby what causes this carby or timing

Cheers

[eldo]

an air leak

[zookster666]

The thing is it doesn't have the characteristics of a vacuum leak it idles fine etc will look into it though

[eldo]

is it running lean so its popping on decel ?
im no mechanic

[zookster666]

Smells like it's running rich Im no mechanic either my 1.3 did it aswell but not as bad

[eldo]

time to pm stekky, hey stekky get over here

[zookster666]

He'll be here sonner or later

[eldo]

spamekky

[BenT]

zookster666 wrote:

My g16a in my Sierra is backfiring on deceleration it runs a Sierra head and carby what causes this carby or timing

Cheers

Exhaust leaks can cause backfires on decelleration. Stick your foot over the end of the exh and listen for a hiss from a leak.

Ben

[zookster666]

There are no exhaust leaks it might just need a good tune I'm picking up a 1.6 carb on the weekend see how that goes

[steak_knife]

eldo wrote:

spamekky

Yes sweet pea??

How bad is it?

What size exhaust do you have & how did you set the timing( if you did)

I found out the hard way that a car with a sport's exhaust will back fire on decell, most time's there is bugger all you can do about it, you said the 1.3 did it to.
eldo is partly right in saying look for vacc leak's, I'd also make sure the carby isn't over fueling, sucking or dribbling at idle.


I'm going to have to start charging you fuel money.

[oozuk]

burnt exhaust valves cause popping and backfiring, also exhaust leaks sucking in air in deceleration

[zookster666]

Ok I'll have a look at it the 1.3 was no where near as bad it doesn't worry me just thought it may be an easy fix it gas a 2 inch exhaust and extractors

[royce]

exhaust leak
retarded timing
rich
all of the above

some engines jsut put though, for no real reason

[zookster666]

I'll give it a tube do the timing put new carby on etc and see how that goes thanks for the help fellas learn something new everyday on here

[hutch]

royce wrote:

retarded timing

my moneys on that, but could be carby?
How is it on acceleraton?

[zookster666]

It's pretty sluggish on acceleration I'll have to get a timing light fm do that

[JrZook]

A rich condition usually doesn't promote backfiring unless the timing is wayyy off. Since you have the 1.3 carb on the 1.6, find the idle mixture screw and set this to run the best at about 1k rpm. This is where the transition ports are just opening and where most of the problems occur.

Dan