Mechanic "fixed" my carb - now no start!

[FiatJim]

I had taken my 1970 Spider (with a '72 motor) into my local mechanic because the engine wanted to keep running when I turned it off. He's worked on the car before and does know what a carburetor is {unlike the new young 'uns!} He wasn't able to get the car to run any better. So, I picked up the car and while driving it home the engine just ran worse and worse,... argh . I limped the car home, having to keep the engine above 3-4K, and seriously slipping the clutch. Not good. When I got it home, I noted that one of the idle jets HAD FALLEN OUT. Fortunately, it landed on the manifold and stayed there. This jet was on the drivers side. The other jet was finger loose. Now the car won't fire at all. There is spark, and fuel - so I am left with the carb & jets. Obviously, I have only a rudimentary undeerstanding of carbs ~ enough to be dangerous

1. What is the installation setting for the jets? The manuals I have give technical info, but not practical "turn it this many turns when you reinstall,...".
2. Would I be better off to send the entire beastie off to and get it rebuilt? If you know of someone, please speak up.

Thanks for the help.

[kmead]

First I would start here and grab the information for your carb:

http://www.artigue.com/?page_id=62

The thing to remember about a carb is they all screw together, its the knowing where things go and in what order that makes the difference. An exploded drawing will assist in that.

Basic setup of a carb isn't very difficult, it just requires carefully following the process. Personally I would get a rebuild kit (which primarily consists of gaskets and a new needle valve), then clean and reassemble the carb following the directions. I would also try to get all of the stated jets and so on in case a bad case of switching parts and losing others has gone on.

[FiatJim]

Thanks Karl,

I was hoping for a "quick fix" so I could keep driving,.. but,... .

I'll take your advice and take the carb off and find the right rebuild kit. I had read that you never rebuild your first carb once - - it is twice because once you reassemble it for the first time you find there is a part that didn't get put into place!!

[redek]

In November of last year my mechanic adjusted my carburetor leaving it undrivable, leaky accelerator pump and no replacement currently available. I quickly replaced it with the new empi that was sitting in the garage. Drive ability was instantly improved, especially cold weather starting due to the electric choke.
Derek

[majicwrench]

Idle jets....the ones near the top of the crab, that go in horizontally, one on each side.....just screw in till they seat. Are these what you are refering too??

Personally, I would not just rebuild the carb. Unless you know what you are looking for when you do. The carb is not likely keeping it from running.
Spark and fuel....then it should run. Are plugs soaked?? Get it running, THEN decide if carb needs rebuild.

Won't shut off.......this is usually a function of idle being too high for whatever reason.
Keith

[FiatJim]

"Idle jets....the ones near the top of the crab, that go in horizontally, one on each side.....just screw in till they seat. Are these what you are refering too??"

Yep, those are the ones. Do I set them all the way? just snug?

I haven't checked the plug - yet. That will be on the list for tomorrow night.
The engine will start with the alcohol spray, then stops when the short spray has been used. So it has spark, and when I check the plugs I'll know about fuel. The fuel filter shows gas in it.

Is there a way to see the stamp on the base of the carb when it is in place? With my darn progressive bifocals, tilting my head to get the right part of lense makes seeing the grungy numbers impossible

[majicwrench]

THose jet carriers just seat em good and snug. No adjustments.
The fuel filter shows gas.....that means amost nothing. Even if car ran out of gas, some may still sit in the filter. Does carb have gas in it?? Pump accellerator and see if any is getting pumped in. If it starts on alcohol, likely no gas in carb.
Good luck,
' Keith

[FiatJim]

Thanks Keith.

I turned the screws all the way in, and it fired up just fine. After gasoline finally got pumped up to the carb. [Do mechanical fuel pumps get weak?]! I have to remember that when I park on an incline to face the engine downhill
The idle is set low, to the point where it reminds me of a Harley: chug - chug - chug.
After a 10 minute drive, as I turned the car off, the engine tried to keep running.
But at least I am back to square one,..

[Sunracer]

the fact your car keeps running is a sign it has an internal leak in the carb, you shut it off and enough gas is still dripping out that the car keeps running. It is called "dieseling" since the car is now running on excess gas and the heat and compression in the engine. Your carb has something loose internally or is just completely shot. Buying a rebuilt unit will likely be the easiest way to go or build it your self if you want to learn. As I understand it the engine actually runs backwards in this condition. The easy way to deal with it is to simply drop the clutch in gear as you shut off. This will kill the engine immediately as you turn off the key and enguage the clutch at the same time.

One other item that contributes to this is carbon build up in the engine. The best product to deal with this is either Seafoam or GM top engine cleaner PB : )

[majicwrench]

Dieseling is NOT neccessarily caused by gas dripping and does NOT indicate that your carb needs rebuild or is shot.
Engine is still rotating in normal direction, would be dang tough to stop the crank/flywheel and get em spinning backwards.
As long as engine is rotating, it is creating vacuum and sucking fuel from the carb whether key is on or not. If cylinders hot enough, and given enough air and fuel, it will continue to "run" even without ignition. Eventually they went to a fuel shut-off soleniod to deal with the situation.
Proper idle speed and mix is the first step to controlling dieseling.

GM Top Engine Cleaner is good stuff. Sea Foam is not in the same league at all.

[kmead]

I would go back through the carb, clean it, ensure all passages are clean, reset the float height and reassemble. What I am suggesting is merely a cleaning with new gaskets, not a rebuild which should replace the shafts, bearings, clear the closed passages and reseal.

Getting to a good baseline is the key to being able to adjust the idle mixture and idle speed properly.

The run on or dieseling could be related to a a high float level or a too rich condition where excess fuel is pooling in the intake allowing the engine to continue to run.

[Sunracer]

Dieseling is NOT neccessarily caused by gas dripping and does NOT indicate that your carb needs rebuild or is shot.
Engine is still rotating in normal direction, would be dang tough to stop the crank/flywheel and get em spinning backwards.
As long as engine is rotating, it is creating vacuum and sucking fuel from the carb whether key is on or not. If cylinders hot enough, and given enough air and fuel, it will continue to "run" even without ignition. Eventually they went to a fuel shut-off soleniod to deal with the situation.
Proper idle speed and mix is the first step to controlling dieseling.

GM Top Engine Cleaner is good stuff. Sea Foam is not in the same league at all.

yes, the carb could be set with the butterflyies open to much, over rich mix etc. In fact I have seen an engine run backwards as the dieseling will occur at a point in the compression stroke so early that the pre ignition kicks the engine into a reverse rotation and it will then sputter to a stop. Idle stop solenoids are found on later smog era FIATs.

A good way to check for symptoms is to use the clutch method to stall out the motor as you turn it off, then with the ignition off, pull the lid off the air cleaner and look for the puddling described above, or from dripping from the carb, due to a leak or overly high float level or perculating fuel. PB : )

[FiatJim]

Thanks guys, sorry for the delayed response - I was unexpectedly hospitalized for a bee bite that got infected - argh.

I will begin to check the things you have suggested as soon as it stops raining here