how do i determine which Carb is on my 1979 spider

[steve8462]

the PO said he had the carb replaced but had no paperwork or info on the carb. i looked at the base and it is stamped on the base facing forward "red line" i have a picture of it but it has the aftermarket air cleaner on it. i will get a better picture over the next day or so. i'm trying to adjust the carb to lower the idle a bit and smooth it out. there is a vacuum port on the right side of the intake on the top side. you will see in the picture has a cone shape aftermarket breather on it. i was advised that i should cap this off since all my emissions are gone. i did so and it dropped the idle down to a stall (Note): the brake booster has a vacuum hose to it from the forward side of the intake manifold.(as seen in the bottom pic) any thoughts as to how i should move forward? thank you

[narfire]

I checked the model type on a 72 I have by using a small mirror and good glasses. There is a model number stamped on the lower carb body that faces the engine. Clean and have a look.

[steve8462]

here are some better shots of the carb. i looked with a mirror on the side of the base and the only legible markings were "f2"

[Weelan]

Pretty confident that's 32/36 DFEV. Looks a lot like mine, and the pictures Joe posted here: http://www.fiatspider.com/f08/viewtopic ... 5C#p138628

[steve8462]

Awesome! thanks for the links and pictures. i'm going to attempt to check the timing, and adjust the fuel mix to smooth our a minor rough idle and lower the idle just a bit. any suggestions of the best order to do this?

[Weelan]

hmm, not possitive, I'm not as good as some of the people here. timing and fuel mixture and idle timing would be a good start.

here's a manual for it. the last page has a few important pieces labeled for you. (it'll be the dfev)
http://www.webercarbsdirect.com/v/vspfi ... 0Guide.pdf

[BEEK]

the filter on the vacuum port behind the carburator, near the firewall, needs to be removed and the port capped. isomewhere i remember a question reguarding this, but to make sure , i mentioned it again

[tartan18]

the filter on the vacuum port behind the carburator, near the firewall, needs to be removed and the port capped. isomewhere i remember a question reguarding this, but to make sure , i mentioned it again

I believe that filter between the carb and firewall is the crankcase vent. It is not a vacuum line. In my car (1975 with the DFEV carb) I have routed the crankcase line into the air filter.



This the fitting where the crankcase line connects in the air filter housing is the small white hose attachment in the upper right corner of the air filter bottom plate.

[

You could just keep the filter positioned as it is but I prefer the crankcase emissions to be re-circulated back though the intake manifold. I have removed all the other emission control systems (EGR, air pump, etc.).

[Weelan]

I thought so at first too, but look at the angle and location of it. I think it's coming out of the intake manifold. You can see the cover plate on your first photo tartan, I think it's coming from there. If that's the case, I think he can just cover it if possible. I don't know but I think it should be fine if he doesn't have anything to cover it with at the moment right? Don't see why not.

[steve8462]

the port on the back side top of the intake manifold (closest to the firewall) has a strong amount of vacuum in it. when i plug it, the engine stalls. should i plug it and turn the idle up to compensate?

[BEEK]

yes, absolutly. plug it and reset the carburator, that may be the problem you are searching. the amount of air coming in thru that vacuum leak is messing up the signal to the carburator. someone has compensated for it at idle, by misadjusting the carburator. but the main and secondary circuits will be way to lean... plug it and readjust

[fiat218]

the filter on the vacuum port behind the carburator, near the firewall, needs to be removed and the port capped. isomewhere i remember a question reguarding this, but to make sure , i mentioned it again

I believe that filter between the carb and firewall is the crankcase vent. It is not a vacuum line. In my car (1975 with the DFEV carb) I have routed the crankcase line into the air filter.



This the fitting where the crankcase line connects in the air filter housing is the small white hose attachment in the upper right corner of the air filter bottom plate.

[

You could just keep the filter positioned as it is but I prefer the crankcase emissions to be re-circulated back though the intake manifold. I have removed all the other emission control systems (EGR, air pump, etc.).

just looking i need a air filter like that, where did u get it, thanks

[BEEK]

it is very wise to keep the crankcase emissions run thru the carburator. it has a nasty smell, one my wife refuses to ride in the car with me when that is unhooked. unless you have excessive blowby there is absolutly nothing wrong with recirculating the crankcase vent

[steve8462]

hey BEEK ! i did what you said and "wow" what a difference! way more power, it doesn't skip anymore, and has a smoother idle at lower RPM's. one question, I've never been good at the idle mixture. where do you start when trying to adjust it correctly? do you crank it all the way in and back it out to a certain point? is there a good procedure that you use? i don't want to end up too lean and burn the valves, and i don't want to be too rich and waste gas. any advice? thank you for your previous wisdom!