1979 Spider 2000 Dual Weber 40 IDF Help needed.

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1979 Spider 2000 Dual Weber 40 IDF Help needed.

Postby lordsiris » Mon Jun 11, 2007 6:37 pm

Hello all!

I just purchased my 1979 Fiat Spider 2000 about a month ago and it's spent the entire time at the mechanic having a good look and replacement of timing belt, and checking the valves and replacing the head gasket plus a few other things. Heres the problem, the mechanic (local Fiat guy here in Indiana) swears that the dual Weber 40 IDF's are just too big for the engine. Says the car is being entirely overfueled and it's causing problems when running the engine at a steady speed (washing out the cylinders). He also says that with the foot on the accelerator and aggressively driving the dual cams do their thing. He is really concerned about turning the car back over to me because of the fueling problem and rough running at normal driving.

Here is what I know (at least what he told me)

Dual Weber 40 IDFs

3 psi from the electronic fuel pump
115 main jet on one carb
112 main jet on second carb
32mm venturi on both
F11 emulsion tube
50 idle jets

The car has standard cams, a header, no catalytic convertor, and a sport muffler, also has a large KN air filter over both carbs.

The mechanic wants to replace the carbs with an original for the year of the car which i believe is a 28/32 and has been described as "anemic" in many places on the web. I guess my question is does anyone have much experience with the dual carb weber setup and could help me out here?

Basically I am at the point where I will just get the car back and try messing with the jets myself or finding another place in the area to get a "second opinion" before moving on to replace the carbs.

Anyone have any idea's or someone that I could contact?

Thanks,

Chris

BTW: I had a 1996 Fiat Coupe 2.0 Turbo while I was living in Italy and it was by far the most fun I have ever had while driving a car, too bad I couldn't bring it back... I am hoping I get to drive the Spider sometime this summer!!
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Postby cohiba » Mon Jun 11, 2007 8:58 pm

I'm sure you can run the duel 40's but from what I have read there are modifications that would help them run at their peak performance. There are a couple guys and gals here that would be able to assist you more in that department, they run them, however stay away from the 28 32 and if you want just a single carb upgrade go with the 34 ADF which is a Fiat weber carb. I understand the 32 36 DGEV is a generic weber that will do just fine but the way to go with a single carb is the 34 ADF. I wish I had your problem and I would keep the duel 40s. Bruces Parts has the best price in town for the 34 ADF.
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Go get the car now!

Postby engineerted » Mon Jun 11, 2007 9:08 pm

Your mechanic is wrong! Does he know that the idfs came standard on the early 1600 motors. There are alot of people running them on 2L not to mention 1.8l, and 1.6l engines. Also you jetting is off, the mains should be the same between the carbs 125 mains to start, 220 air, 50 idle, idle mix screw 1 turn out to start. set timing at 10deg static. There is alot of info on this subject, do a search for idf jettng.
Ted
78' 124 spider complete ground up resto
74' 124 FP race car
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Postby Denise » Tue Jun 12, 2007 8:13 am

These guys are right. I don't believe there's reason you can't run these on a 2L. I'm running dual IDFs on a stock 1608 and on a higher performance 1608. Maybe you should try 125 mains and 210 to 195 air. I also run 00 bleedbacks and timing at 10 degrees. Is your mechanic familiar with tuning these? It takes a lot of patience and a synchrometer to get them tuned right. I also learned the hard way not to use a restrictive air filtering system on them. They need a lot of air.
I may have some extra jets in my stash if you need them.
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Postby allenlofland » Tue Jun 12, 2007 8:47 am

Well First thing, 8) GET THAT CAR AWAY FROM THAT MECHANIC,,,,Really, with this kind of advice I wonder what else he has done to you.
Next, those specs on the carbs are interesting to say the least, 3 psi from the electronic fuel pump
115 main jet on one carb
112 main jet on second carb
32mm venturi on both
F11 emulsion tube
50 idle jets
How do you know the fuel pressure, is there a regulator in the line ???if not, get one at the local part house, easy install and set for 3 lbs,
mains should be the same, good grief, how doese he think he can balance them.
I run 125 to 140 depending on the car. Start at 125 for my opinon.
One thing I can tell you for sure. Weber dual 40's on a Fiat 2 liter are very proper and also very easy to live with Once you learn how to use them 8)
Get the Haynes weber book, get the balancing tool, the good one from Pearce Manafold or other vendors, and learn them your self. If you depend on your mechanicyou will get just what you pay for, BAD ADVICE.
haha.
Seriously they are NOT rocket science, learn them 8)
Allen & Lynette Lofland
Wichita Kansas
Back on Land with Our Fiat :)
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Postby mbouse » Tue Jun 12, 2007 11:16 am

INDIANA? DID YOU SAY INDIANA? just where in indiana are you?

we have several FLU members in Indiana, and Michigan, not to mention (o.k. I guess i will mention) Ohio. Depending on where you are.....there might be a brother or sister Fiat Freak that wouldn't mind stopping by and drooling on your fender....I mean, helping out.

I've heard far too many mechanic stories to believe anything negative. Most everything CAN be done. When they say NO, they usually are saying that they don't KNOW. I don't know your mechanic, but it sounds like he is selling you a bill of goods. Ask him what he's gonna do with those dual 40's after he rips them off your intake..... I think he is giving more than bad advice.

Ummm, by the way...did i mention that there are at least TWO active FLU chapters in your general area? Get ahold of one of those groups and you will get a lot further than where you are, for a lot less money (unless you have cash to spare). Most of us like to get our hands dirty for free.
Mike Bouse
WEST MICHIGAN FLU Treasurer
FLU Board of Directors
1978 Fiat Spider mostly stock
1980 Fiat Spider modified
mbouse2000@gmail.com
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Thanks

Postby lordsiris » Tue Jun 12, 2007 9:26 pm

Ok, I will be getting the car back from the mechanic on thursday. Guess I need to get a few things on order and do some further reading. I have read stuff all over the net but I guess I just wanted to make sure I wasn't losing my mind.

mbouse... I am in Fort Wayne, only about an hour south of you. Originally I am from Angola and used to go to Coldwater for some shopping and the theater.

I will probably be joining the group here soon!! Thanks everyone it's awesome to have such a great community...

Chris
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Postby Dwight V. » Wed Jun 13, 2007 5:58 am

I'd recommend you whip on over to http://forum.mirafiori.com/mirafiorum/ and post in the tech area. Title your post "IDF University Questions" or something. There are a couple of resident experts over there, one of whom has IDFs on his Spider 2000 by the name of Carl Friedman who has done most of the hard work figuring out how to make these run properly on your application. Carl is a good guy and member of DC Fiats but doesn't visit this message board often, if ever.
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Postby mbouse » Wed Jun 13, 2007 11:05 am

And, when you get back on the road, give me a shout. i am very active with the WEST MICHIGAN FLU chapter, and usually have something going on with them.

Or, we can meet in Auburn for Ice Cream!!
Mike Bouse
WEST MICHIGAN FLU Treasurer
FLU Board of Directors
1978 Fiat Spider mostly stock
1980 Fiat Spider modified
mbouse2000@gmail.com
Home of the Michigan SHORTER SHIFTER
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Car is now in the garage...

Postby lordsiris » Thu Jun 14, 2007 7:57 pm

Ok, finally got the car back. It was a rough ride home trying to keep it from getting flooded, it finally did about 100ft from my driveway but I was able to get it started again. I really didn't feel like pushing it that far!!

What specifically is the "Pearce Manafold" that you speak of, the synchrometer? Can you provide a link?

I took a look around the mirafiori forum and it's kinda annoying to use, but I will press forward, didn't find much information there yet but I haven't stopped looking.

Anyway can you guys take a look at this pic and tell me what the bronze/copper tube is on the left and if it should be there on the right? This is the carb closest to the firewall if that matters at all. Also do the main jets in the middle just screw out or what?

Image

Thanks,

Chris

As soon as I can safely (meaning not worried about car catching on fire) I would be glad to meet up in Auburn. Is there a really good ice cream place there I have been missing out on?
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Postby Denise » Thu Jun 14, 2007 8:30 pm

Those brass tubes are mixture enrichment tubes. They are used as a high speed mixture enrichment system. The fuel from the float chamber goes is pulled into the tubes so the it can be sprayed into the horns of the carb. I don't know much about how carbs work, but I would think it a good idea to replace that tube since the spray pattern isn't the same. The jets do screw out and consists of an air corrector jet, emulsion tube and main jet.

Pierce Manifold is where to get jets and rebuild kits for your carbs. Their link is: http://www.piercemanifolds.com/

This is what a synchrometer looks like and helps to get the same amount air through all four ports, which is essential to getting them tuned properly.
Image
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Postby allenlofland » Thu Jun 14, 2007 11:31 pm

Glad to hear you got the car out before he ruined it :)
By the looksof things you will probably simply find that the carbs are in need of cleaning-sorting out jet sizes and general fooling around with 8)
BUT FIRST you need to know a little bit about them, like what are those things and these things and what do they do :)
Get the Haynes Book,,,,,it will greatly answere and show you these things,
Also a note of warning....These carbs are old..good but old, some parts are not to available, like those shafts that go thru the carbs, DONT DONT DNONT
Soak these carbs in carbuator cleaner or anything else . Done EVER soak them or dunk them in solvent of ANY KIND. and here;s why.
those shafts are sitten on greased bearings and in order to lube the bearings you will think, I have to pull the shafts out, and to do that I have to take the butterfly's of, and then gently DESTROY the shafts. They normally DONT come out, dont even try it. Clean them with the spray type carburator cleaner, set them in a pan and spray away, drain them good and blow dry. The bearins on each end that you can not expose can be force fed some good grease thru the washers carefully, dont pry.anthng apart :) those buterflys are opened and shut equally by the shafts and if the shafts get twisted any, and this doese happen a lot, you will have to twist them back . Turn the carbs over, hold them over a lighted bulb, see if the four buttterflys all opern evenly , the light will show thru them as you slowly move the sahfts, There are adjustments between the two carbs but the two per carb butterflys are only salvageable by actually carefully twisting the shafts back in place, DONT attempt this correction until later if it is needed, as you might find that once you dig further into them there are other consideration involved. I am mentioneing this now becasue I have heard to many times that some one has ruidned a set by soaking them in carb cleaner and trying to remove the shafts.
Now that you have them cleaned and greased, sit down with the Haynes Webber book and READ.
Enjoy, you will be amazed at how much fun these dual webbers can be and the new friends you will make talking about how you saved yours . 8)
O and that tube that is broken of, I went to the hobby store and bought some brass tubing, bent a replacement to match the other one for about 3 bucks, works fine :)
When you get to Mirafiori site, ask for Carl the carb man and tell him I sent ya :) hes the one that saved me years ago.
Allen & Lynette Lofland
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Postby mbouse » Fri Jun 15, 2007 10:15 am

Auburn is a great half way point for us both. When you are ready, give me a shout. Besides the standard ice cream parlors there is an EXCELLENTlittle pub with a great grill .. and .. their very own micro brewery.

My eldest daughter and her hubby live in Auburn, so i get to see the local sites frequently. they like to take me out for an Abbey's Pale Ale every now and again.

Good luck with those carb issues. Sorry I can't help there.
Mike Bouse
WEST MICHIGAN FLU Treasurer
FLU Board of Directors
1978 Fiat Spider mostly stock
1980 Fiat Spider modified
mbouse2000@gmail.com
Home of the Michigan SHORTER SHIFTER
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lol

Postby lordsiris » Fri Jun 15, 2007 8:14 pm

Just decided to buy a fuel pressure gauge to make sure it's at 3 psi (figured that the mechanic can't tune carbs that maybe they can't read a fuel gauge either) and amazingly it's NOT at 3psi like they said but actually 6psi. Guess that would probably mess everything up!! Back to the store tomorrow for the 1-4psi Holley fuel regulator.. Simply amazing!

Chris

mbouse... I am familiar with the micro brewery, haven't been to the one in Auburn but many years ago I visited the one in Fort Wayne a couple times.
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Postby allenlofland » Fri Jun 15, 2007 8:18 pm

Your getting the idea :D
Now you have to realize thst if the fuel pressure was the problem you still have to correct what really has happened and that is you have flushed out the needle seats.
You will need to reset the floats and install new rebuild kits .
But first get that presure down. 3 max....
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