1.8 Backfiring?

[Ray Morgan]

Here's the story:

My 75 1.8 sat for about 5 months. It was also out of gas. I finally get some gas in it, get it running, hit it with some starting fluid. It fires right up, idles strong.

I pop it into gear, and take it for a drive. It is back-firing -- but only on deceleration, NOT on acceleration.

For example, I'll be cruising down the street, take my foot off the gas, downshift, and it'll back-fire. Then, if I step on the brake, again, back-fire. It doesn't do it at idle, start-up, or any other time.

Have any of you guys heard of this? Any suggestions?

Thanks!

[Dave at Pelican Parts]

Could be an exhaust leak, or could be an overly-rich mixture, or an overly-lean mixture, or a problem with the ignition system, or....

Can you tell if it's backfiring out the intake or the exhaust? The intake is especially bad for 1.8 engines, as a good one can warp the flap in the air flow meter... $$$$$!

--DD

[Ray Morgan]

It's back-firing through the tail-pipe. And the tail-pipe is caked with soot, and smells like fuel.

This is a new problem -- not one I had before. [Sigh] Just what I needed for the holidays.

[Dave at Pelican Parts]

Ignition or fuel, then. The sparks not happening (or happening at the wrong time, more likely), or too much fuel.

--DD

[M. Hendrix]

First plugs, they are fouled by now anyways.


M