Backfire

[ralphcap]

This backfire incident happened the day before I left town and y'all may find it hard to believe but I didn't even pop the hood to take a look. The winter is usually my driving season but its even been cold down here below sea level. So, I'm not as motiivated as I would normally be to get her running. Popped the hood this morning and found that the air flow snorkel (hose or whatever it's called) was detached at the end opposite the airflow meter/air box. Left it like I found it even though the car is garaged. If the weather is good tomorrow I'll reattach it and let y'all know what happens. Suprised and appreciative of the interest. Brad, if it's anything more complicated than slipping the hose back on you'll have to return to the area to fix it!

[bradartigue]

This backfire incident happened the day before I left town and y'all may find it hard to believe but I didn't even pop the hood to take a look. The winter is usually my driving season but its even been cold down here below sea level. So, I'm not as motiivated as I would normally be to get her running. Popped the hood this morning and found that the air flow snorkel (hose or whatever it's called) was detached at the end opposite the airflow meter/air box. Left it like I found it even though the car is garaged. If the weather is good tomorrow I'll reattach it and let y'all know what happens. Suprised and appreciative of the interest. Brad, if it's anything more complicated than slipping the hose back on you'll have to return to the area to fix it!

I'll do it myself this time!

[ralphcap]

Improved weather so I pushed my spider out of the garage and discovered that both ends of the air hose were detached as a result of the backfire. Did not notice any other problems so I reattached both ends. She started up right away and I took about a half hour spin and she ran well.

[bradartigue]

Improved weather so I pushed my spider out of the garage and discovered that both ends of the air hose were detached as a result of the backfire. Did not notice any other problems so I reattached both ends. She started up right away and I took about a half hour spin and she ran well.

Well then Ralph, did you tighten the thing on both sides this time? Because.......it doesn't fall off on both sides unless it is loose.

Glad it is running. I would have hated to be right about a valve or wrong about your sparkplugs, magicwrench would have either had to add a 6th digit to his hand OR i'd have to eat crow about the valve being sticky.

[76was124]

Dare I ask if the root cause of the back-fire should be a concern?

[bradartigue]

Dare I ask if the root cause of the back-fire should be a concern?

I can guess at the root cause - the hose was loose on both sides. It moves to and fro (the engine isn't connected to the air box except by the hose). It got cold, shrunk, it fell off. When hot it expanded (in all directions) and tightened.

Usually when it blows off the air forces it the hose off the AFM side after it blows the door backwards or the safety door on the vane open. The big boom is not from the air blowing the hose off, it is the engine gulping a big blast of unmetered air, causes a backfire...er, frontfire?

[76was124]

Sorry, my question probably wasn't very clear. I was wondering what likely caused the initial back-fire, and should the cause of the back-fire be of concern? Or did you answer that by saying a loose boot (basically causing a high lean condition) is a possible cause of a backfire, which blew the boot all the rest of the way off?

[ralphcap]

I had a hose clamp on the Air Flow Meter side of the Air Intake Hose but did not have a hose clamp on the opposite side (intake manifold side?). Sounds like I should have a clamp on both sides and that they should be as tight as I can get them.

[RRoller123]

Yes hose clamp both ends, firm but not overly tight.

[bradartigue]

Sorry, my question probably wasn't very clear. I was wondering what likely caused the initial back-fire, and should the cause of the back-fire be of concern? Or did you answer that by saying a loose boot (basically causing a high lean condition) is a possible cause of a backfire, which blew the boot all the rest of the way off?

No idea - sounds like the thing just fell off. Then in a few milliseconds it takes in a big gulp of unmetered air and the engine is already dying, so it blasts is all back out the wrong way, or through a half open valve.

[ralphcap]

Well, thanks everyone. Installed clamps on both ends of the Air Intake Hose. Glad it was something simple. Now all I need is much improved weather! Over and Out!