Contradictory manuals - need help!!!

[spidernut]

I am looking for assistance with the vacuum lines on the following vehicle:

77 Fiat Spider
32 ADFA carb, California emissions (must remain intact due to smog checks), Catalyst car

I am replacing vacuum lines due to age and emissions problems and ran into a HUGE issue. I have consulted with the Fiat shop manual, Haynes Manual, Chilton's manual, Brad Artiques ADFA manual, the Weber ADFA manual, this forum and Mirafiori.com. They all seem to be incomplete in this area and contradict one another.

Let's start with the shop manual picture:


Port 1: The Fiat manual states this is the crankcase blow by connection. Another graphic in the Fiat manual shows it goes to the small air port on the bottom of the air filter canister above the crankcase ventilation hose. However, the other manuals show it goes to the top of the charcoal canister. So which is it? Does it go to the air cleaner or the charcoal canister?

Port 4: This is the float bowl vapor outlet. Logically, it would connect to the charcoal canister but NONE of the manuals depict or describe where it connects at the other end. Top, side? Somewhere else entirely?

Port 8: The Fiat manual says this connects to the vapor canister. Top, side? The other manuals don't depict this port at all. Gheez.

Port 10: The Fiat manual lists it as the EGR vacuum source. The pictures depict it connecting directly to the thermal control valve then to the EGR valve. However, there's a front electrovalve located on the driver's side fender that has been described by others on the forums as the EGR electrovalve. The electrovalve, of course, is not mentioned in ANY of the manuals. The only one mentioned is the fast idle electrovalve which is connected per the Fiat manual. How are the vacuum lines to be run for the EGR electrovalve if that is what it really is?

If you know how these are supposed to be run properly (again, I cannot disconnect the emissions system), please let me know. The manuals are so incomplete and contradictory it is mind blowing. I'd default to the Fiat manual but it is incomplete as well.

HELP!

[So Cal Mark]

1. definitely connects to the air filter crankcase breather
4. side of the cannister
8. top of the cannister
10. the line runs to the egr thermovalve but has a tee in it with one leg connecting to the electrovalve

[spidernut]

Mark,

Thanks so much. This is what I surmised and excluding the electrovalve is how I have it plumbed right now. I have one additional question for you regarding the electrovalve.

Regarding port 10 on the carb, here's how I have it set up currently:

Port 10 to the electrovalve
Electrovalve to thermovalve
Thermovalve to EGR valve

Am I understanding correctly that it should run as follows?:
Port 10 to a T connector
One end of the T connector to the thermovalve
The second end of the T connector to the electrovalve
The remaining hose on the electrovalve goes ???

What exactly does this electrovalve do for the EGR system? It seems redundant since there's already a thermovalve in the system. Is it cutting off or opening the vacuum at certain RPMs, during acceleration or deceleration, or at idle? I understand the operation of the other components, but this one has me stumped.

[spidernut]

I found this thread - is this what you're referencing?

From this image, Port 10 would be the source vacuum to the thermovalve. The thermovalve when warm would open up and create a source vacuum to the electrovalve and to the EGR valve simultaneously due to the T in the line. So where does the other vacuum port on the electrovalve connect and what does it control?

[So Cal Mark]

it's ported to atmosphere as a bleed-off

[spidernut]

Thanks Mark. I greatly appreciate your expertise with our cars and the assistance you provide. I'm not sure how we'd keep these cars on the road without you and the others who regularly offer free advice to us.

John

[bradartigue]

These things are documented about 10 different ways because it is quite confusing. They never split up the Federal and California plumbing except in supplements and service letters and the translations are sometimes awful. I honestly think they figured the dealerships would disconnect all of this stuff anyway (many did).

[spidernut]

Brad - I wish I could disconnect it all too, but the morons who run California still require me to smog test a 38 year old car.

[bradartigue]

Brad - I wish I could disconnect it all too, but the morons who run California still require me to smog test a 38 year old car.

Well nothing stops you from putting a plug inside the hose. These cars run so clean...the equipment was a bunch of crap.