HELP! before i go crazy Options

[D0ctorg00se]

Ok, so i have a '74 2.0 that was carb converted (unkown single dual progressive) when i bought it 5 years ago. Since then i have done the 009 dist, facet fuel pump, etc. (but of course no new cam, yet). Exhaust is monza quad tip, in good shape no holes. The fuel lines have all been replaced. The car has really been a dream considering i live in Blacksburg, VA and drive it daily. I upgraded to dual delorto's which ran fairly well considering they were used but one actually cracked and began to leak fuel into the crankcase. So i just recently put a pair of brand new dual EMPI, HMPX 44's on and i just can't get em right! Now they are synched and linkage should be fine I have recently adjusted the valves and they should be fine (i keep saying "should" be b/c im no expert and if it could be the problem then it could be). The car starts right up, idles fine (not perfect but good enough) and at full throttle it is fine. It is at part throttle that the trouble arises. Basically unless i push it hard past half throttle it runs like crap. Maybe at like an eighth or less it is ok, like easing off really slow. But as soon as i get on the throttle part way it lags, pops, sputters, hisses, jumps, and just has a fit unless i get on it more or feather it goofily. So i've basically tried the mixture anyway it can be (while still being able to start) rich lean whatever and while sometimes it seems better than others its still not where i feel like it should be with a brand new set of carbs. So someone please help me out no mechanics have ever worked on a 914 down here so i hate taking the car in to have some hilljack screw with it. I havent checked/adjusted the timing or dwell yet but im not sure if i need to. Someone please hook me up with some knowledge. I know you gurus have the uber knowledge i need. Let me know what you think.

[ClayPerrine]

First thing... an 009 has the wrong advance curve for a 914 motor. Find an 050 distributor. Give the 009 a Dave Darling "float test".

Second... 44mm carbs are too big for a 2.0 with a stock cam. If the carbs have changable venturis, change them out for smaller ones. Some of the carb experts on here will probably be better sources of info about tuning them. I prefer fuel injection........


Good luck and welcome to the board!

[D0ctorg00se]

Hey, i appreciate it. What do you mean by Dave Darling "float test". And what's the difference in the 2 distributors i just did what a guy told me i should do when i did the carbs so if the 009 is bad i'll change it out for the 050. I was just told to switch to the 009.

[ClayPerrine]

The Dave Darling "float test"........

Throw the distributor in the lake. If it floats, use it on your car. (IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif)


Seriously, the 009 was designed for a static speed engine used in irrigations system pumps and generators. It was never designed to be used in a car. The advance curve runs out way too quick. To get it to work in a car you have to put in a bunch of static timing, and you still won't get enough advance on the top end. But for some reason, a lot of VW bug guys think it's the "must have" performance distributor.

The 050 is basically the distributor used in the 356. It has a far more appropriate advance curve for an automobile engine.

Oh.. and I forgot to mention.. "009 Distributor" is considered dirty words here......

[SLITS]

Damp Dave's "Float Test" is throw it in the nearest body of water and see if it floats.

The 009 mechanical advance curve is not ideal for the engine you have. A better choice is the 050 mechanical or even a 1.8 L-Jet dizzy.

Don't have specifications on the actual advance curves, but I believe the 009 is to short resulting in a static timing that contributes to a hard start.

Secondly, the sputtering unless you floor it could be inoperative/clogged accelerator pumps.

Krap....Clay beat me to it!

[ClayPerrine]

SLITS... you are old and slow..... I already said that!!!! (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[LvSteveH]

To elaborate on what Clay was saying, the 009 has a very short advance curve, and does not match the needs of the type 4 very well. Before giving your 009 the "float test" (which means to toss it into a large body of water to see if it floats), check your advance curve. The 009 can be recurved to fit the type 4 very well, and there is no need to swap it out if that was done. I put in an 050 on one of my engines only to find out that the 009 had a full 25 degrees of advance as opposed to the 16 or so degrees that most 009's have. No harm in checking first.


On Edit: obviously I was beat to the punch, what is everyone doing on here in the middle of the day?

[SLITS]

QUOTE (ClayPerrine @ Oct 31 2005, 01:42 PM)

SLITS... you are old and slow..... I already said that!!!! (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

Yeh, but I have this magnetic attraction that just collects Hooter's Girls............

[SGB]

All previous statements are correct, but that 009 isn't causing the stumbling. Prolly to venturis too big is correct. Also, you may wanna try checking to see (using uni-syn or other carb flow measuring tool) if the carbs are still equal at various RPMs. My linkage (actually the lever arms from the cross-bar) can be moved, and it effects the angles/ geometry so that the carbs open at different rates- so it would be in synch at idle- or i could balance at 3000 RPM and it would be in synch under acceleration. It has been a trial-and-error event for me, but both my webers are now pretty close at 1000 RPM and 3500 RPM, but a little off at 3000 RPM still, so I'm gonna move 'em around a little more soon.

[D0ctorg00se]

Man wow you guys are such a big help. This is great i really appreciate it, what a forum. So i think im getting the 050 distributor, im gonna order it tomorrow. And as far as makin sure the carbs are equal at different RPMs, i havent really done that so im gonna give it a go. I was tinkering with the mixture and i think i've got it as good as it is going to get, and its not bad but hopefully this new distributor and a a little re-synchin will have me going nicely. As far as different venturis, how do i change them and do you guys think i can get smaller ones, i had no idea 44s were too big, i just went with the bigger ones cus i thought it'd give me more oompf, (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) . Im going to look into smaller ones but let me know what yall think.

[r_towle]

Im not gonna repeat the 009 dizzy thing.

The carbs will work.

It sounds like your main jets are wrong.

You need to call aircooled.net and tell them all the details of your engine...

Include in that the size of you jets, tubes, venturis etc...

get the weber book on tuning...basically its the same carb, though the parts are different.

Aircooled will help alot, they have many verified configurations that other people have been successful with and they will work with you till it runs perfect.

Rich

[MecGen]

Hey Welcome to the club (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif)

When I swapped to my 36 Dells, it was a learning experience to say the least. I agree with the advice above. But I have been running a 009 for 12 years.

Later
+Karma

(IMG:http://www.914world.com/bbs2/html/emoticons/beerchug.gif)

[Joe Ricard]

Actually gained power moving from 44 IDF's to 40's and then gained more by getting longer smaller ID intakes. And that is with my hopped up 2.0L a stock 2.0L would have difficulty getting enough air to flow through them big carbs to pull the car out of a wet paper bag. But I bet it will rev like no tomorrow over 5K RPM's

I switched from 050 to 009 dizzy and didn't notice much other than it ran better with 009 and compufire trigger. Mallory 6a ignition.

I got the 050 on a shelf taking up space. Pm me and I'll get it going your way.

[D0ctorg00se]

Ok, so update: i decided to check and see about my distributor and its not an 009! its an 056??? I guess i mean im going by the last three numbers like u always do, it is a bosch though. Anyway i have been tweakin them a little and i have got them so that they idle ok, still good under most/full throttle, but basically just lag really bad under less or part throttle. I talked to the guys (emailed) at aircooled.net but they just told be the HPMX's were garbage and to buy Weber's, riiiiiiiight. Like i have that kinda money, haha. Anyway does anyone have any other ideas, or still try and replace my distributor and i need smaller venuris' (which i dont really want to buy). Basically i want to make what i have work if possible and if not, i want to get buy with as little purchases as possible, not afraid of putting in work tho.

[DrifterJay]

I might have some Dellorto 40s that a properly jetted, and a Mallory Unillite set up already available in about a month or so...

[Sparky]

What are your jet sizes? CAll Empi dealer and explain what is going on. They should be able to recommend the correct set of jets.

Mike D.

[IronHillRestorations]

The guys at aircooled.net may be right. I don't have any experience with those carbs, but if the car ran well before you changed carbs......

If you have 44mm venturis, they are big for a stock 2.0 with a FI cam. The generally accepted venturi size for an engine with a 500cc displacement per cylinder (2.0 four or 3.0 six) would be 36's. This is however, relational to the cam profile, which if yours is a stock FI cam is very mild.

Do you know, or can you find out the venturi and jet package for your carbs?

If these are some kinda new carbs, then you could be screwed. It's not unusual to have products thrown out on the market that just don't work properly.

Sorry, but I agree with getting Webers, at least you won't be doing the Star-Trek thing......going where no man has gone before.

PS if those carbs were cheap, there's a good reason why....sorry

[SLITS]

Go to the library and read about venturi theory.....velocity thru the venturi is critical in a carburetor for atomization of fuel. If the "holes" are to big, the airflow at part throttle does not provide sufficient "signal" at the fuel ports to pull the fuel and atomize it properly. You get big dropplets and lots of air, causing stumbling and poor driveability in low and midrange.

While Webers have interchangeable / replaceable venturis, I know nothing about the carbs you are running. You could call and ask if the venturis are replaceable. If so, you could downsize them a bit to get the effect you want. Decreasing the venturi size will cause a bit of loss on the upper end of the RPM range, but you engine is not designed to spin up in the high ranges anyway.

Short intake manifolds can lend to this problem also. As the intake valve closes, there is a reversion wave that comes back up the intake tract, disturbing the flow thru the venturi. Longer intake manifolds can lessen this problem.

This is very general. While in the library, study carburetor theory for a fuller understanding. It's all there for you to learn.

[D0ctorg00se]

Thanks guys, i'm gonna do all that. I've been reading but i need to read some more. I think i can make these things work even if it takes changing out some things but we'll see. I just don't have the money to buy a new set. I'm going to call EMPI as well to see what they think, its not like they are a new company (although the carbs are). So thanks and wish me luck. Hopefully i won't go crazy.

[lapuwali]

FWIW, I believe the EMPI carbs being referred to are the infamous Chinese-made Weber IDF knockoffs. If that's so, then the 44 refers to the diameter of the throttle plates, not the venturi size. The venturies come out after you remove the top plate, the aux venturi (the smaller tube in the center of the throats), and loosen two bolts on the side of the carb (the side away from the mixture screws). The venturi size should be stamped on the venturi somewhere. 32 to 36mm vents would be roughly what you'd want, with 32s better and low-to-midrange, and 36s better for top-end (but you'll still have some poor running at the low-end).