Carb top butterfly value wired open... Why?

[markpink]

Hi. My 1977 was restored by a its former owner, he was a decent mechanic and alot of the car was re-wired and other parts restored to factory condition. He did a fantastic job. Then he did some strange things every now and then. He created his own fuse Box. All his new wiring went here instead of the original. (Well it all works from here) The things still wired to the original fuse box have connection issues sometimes.

He removed the original air cleaner and removed the smog belt. He built his own air cleaner. It is really kinda ugly. I tried replacing it with a sport air conditioner from Vicks and found the holes did not line up. I am sending it back and trying to figure out what size air filter I need with the homebuilt one. I will take the dirty filter to the local auto parts store and see if they can figure out what I need to replace it. It looks like several of the aftermarket air cleaners do not work with the 1977 Fiat 124. It must be something different about this year.

The car has been ok, (except when I do stupid things described in other forums). A constant problem has been backfiring when I take my foot off the gas in any gear...

When I looked at the carb, this past weekend, I found that the top butterfly valve of the carb was wired open with a piece of small wire. I took off the wire. The value closed and now the car doesn't backfire. Why would someone do this?

The mechanic former owner/ died two years ago in a motorcycle crash. I bought the car from his father who did not know how to open the Hood, so the former owners are not able to answer questions.

Thanks

NH Mark

[mbouse]

why does anyone do anything other than 100% restore back to factory specifications? Ever? me thinks this guy didn't know as much as he professed when it came to carburetors.

if the carb runs well with the wire removed, fagedaboudit. the "whys" aren't nearly as important as the "how to fix"

[So Cal Mark]

I'll disagree with Mike about the carb; running with the choke closed will kill performance and gas mileage. A common problem is the choke pull-off diaphragm. Those fail and leave the choke plate closed while the engine is warming up causing a very rich mixture, stalling, plug fouling and poor performance.

[markpink]

Mark,

THe choke still opens and closes fine, the way it was supposed to. I just was wondering why someone would have wired it to remain open all the time. As soon as I removed the wire, I started the car and observed the choke opening and closing, and supposedly acting normal.


NH Mark

[So Cal Mark]

in my experience, people usually disable or bypass something because they don't understand how it works

[mbouse]

i agree with mark on that.

"why" is not always the best question... except if you are in pursuit of human nature. "how" is a great question, cuz that can put things back to correctness---as in "how do i fix the previous owner screw up?". that was my point in my original response. in this particular case.... who cares "why he did what he did" ?

[Zamise]

Not sure which is the top butterfly? But someone had wired the secondary on mine to not shut all the way, the goofiest thing I ever seen, they actually broke out one of the 4 main bolts that hold the carb on to put the wire through it to hold it in place. The carb needed rebuilt, and the main prob were the diaphrams had been rotted out, one leaked gas, the other leaked air. They also had a ball bearing stuffed way up one of the hoses that came off the carb that went to the engine somewhere too, I was lucky to catch that, after that I checked all the hoses. Yeah, I can't say why they did it, but you know indivual parts are pretty cheap to replace, why do something goofy like that to the carb, however these old carbs are pretty complex things, how they ever got them to work in the first place I can not say, they are like a 3D puzzle.

Zam

[markpink]

I know exactly why the previous owner wired the carb top butterfly valve.

The car did not start today. I took the air cleaner off and found the top valves stuck closed. I manually pressed down and they opened and stayed open. The car then started fine. I believe that is why he took the really lazy way out and just wired the valves to stay open all the time. This is the first time that they got stuck in the 6 weeks that I have owned it.. I guess I add Carb Rebuild to list of winter tasks....


Mark from NH