I thought that a struggle that high isnt suprising with out having the header installed. I can try upping the PSI though. Spark plug wires I don't remember off hand. I got them last fall from O'Reilly. BWD brand I think

 

try upping the fuel pressure to like 3 and see what happens.

 

I have had much success with a larger idle fuel jet. Try an 80. It helps the progression circuit, when you progress off idle and up to main circuit.
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Also, with that long manifold and 39mm chokes the engine does not like when you stab the gas pedal a low rpms.

 

I dont necessarily have to stab the gas to get the same result I should mention. If I ease into the pedal the same thing will happen. Its like a certain amount of throttle causes the issue. So it must be something mixture related it seems.

What doesnt make sense is if i give it enough gas to kill it, and let off, it will return to idle, but theres no smoke from unburned fuel out of the exhaust. Its almost as though its rich at idle, and then super lean when the progression hits. It seems very odd though. 180 jets made it bog from 4k and less, 250 makes it bog from 3k and less. So I need some massive jets it seems. Just doesnt seem right.

 

The progression circuit is running lean. Buy Larger idle jets. Try an 80. You tune your main circuit with the main fuel and main air jets, at wide open throttle. TUne the progression circuit with the idle fuel jet and the idle jet holder. The progression circuit controls light throttle steady cruise as well as throtle tip-in.

Your 250 main fuel jet is a band aid.

 

this is exactly what we've been trying to say. there are two circuits in the carb, the idle circuit and the main.

the idle circuit works from the POSITION of the throttle plate and intake vacuum. the throttle plate next to the idle/progression hole is what creates the low pressure to pull fuel out. the problem with this is that once the throttle plate moves more open, the there is less vacuum on the hole, so it meters less fuel.

the main circuit basically works off the velocity if the air going thru the carb (its actually the pressure differential between the float bowl and the boosterish), and as such IT DOES NOT WORK when the throttle is closed, as there isn't enough signal.

so what you are experiencing is that the throttle is moving away from the idle/progression holes, so they stop working, AND the main circuit hasn't yet started to meter fuel. which = the car stops running. AND you can be really rich on both sides of the lean spot (you can actually get it to be a rich spot ) and still have it so lean it won't run.

THE FIX?

so what we do with the webers is pull the main jet stack out and go drive it. this disables the main circuit completely. this will show you in like 20 feet exactly what the idle circuit is doing. make notes. once you get out of the idle circuit the car will stop running.

the second test is for the mains, put em back, and bring it up to an RPM a little before where the idle circuit stops, floor it, if the jetting is right it'll just go. if its wrong it'll go for a second and then stop running.

so once you have an idea what the engine wants, then you can approach a fix. a smaller main air corrector will make the mains come on earlier, a bigger idle fuel jet will deliver more fuel on the idle circuit, so it will stay on later.

i suggest you actually try all the jets you have, trying one thing at a time, and as you learn what the engine wants and what each part does it becomes really easy. i kept a little journal with mine.

 

So more than likely I just need smaller main air corrector it seems. Makes sense. I am however going to take this carb back off the car and tear it down completely and have it cleaned. Just one more variable to knock out. I also will have the cash pulled together for a header at the beginning of April hopefully.

 

i'd try the air corrector first, wacky would do the idle jet, but you just need to do something. you shouldn't be afraid to make it run worse before you make it run better. nobody magically has the right tune, we all started with a crapy running car, and played with it until it was good, or the neighbors came over and said it was loud enough to wake the dead

in the tuning process for mine, ive rebuilt the carb a few times. be picky, and clean is important, but everything must WORK too.

 

lol

 

It would be nice if I could find the jets and carb parts somewhere close by too lol. Shipping from the UK takes a while

 

index drill is my best friend...and he can be yours too

 

yeah, better than waiting!

you can solder up the holes too if you need to go smaller

 

I wouldnt trust myself that much lol. I also called racingbeat yesterday for kicks and they informed me they haven't done anything with dellortos in 19 years and he couldnt even look up the jetting guide lol.

Oh well, I ordered the rebuild kit yesterday and I'll be having a local VW shop rebuild it for $100 they tell me. Also by the time this is all done, I'll probably have my header as well. Hopefully I won't need to post in this thread anymore but we'll see lol.

Thanks a ton for the help guys.

 

awe *** on and grow some *****

 

(without the sexual innuendos courtesy of wacky) Awwww come on, it's seriously easy to rebuild that thing just DO NOT lose the tiny ***** for the pump jet....they are very VERY easy to lose.

 

I'll get some once I upgrade to an RX3 someday lol

I rebuilt one before, but the shop I took it to I trust with my life. Theyre awsome. I figure they could use the business in this economy and it saves me time. This way I know it'll get good and clean too

 

Good luck with that. I hope they know is not a VW based Dellorto and that
some of the mods need to stay as is.

 

They know my car and rotaries pretty well. The owner of the shop had an rx3 back in the day that he ran aftermarket carbs on. Just so I'm clear, the only thing they need to keep is the needle/seat, e tubes, and remake the extra gasket for the AP correct?

 

Make sure they don't replace the accelerator pump arm....RB put a slight bend in it to give it a longer shot (not the arm that is actually on the AP....the one that it connects with which leads up to the main throttle shaft)

 

I'm sure they won't. Theyre basically just going to give it a very thorough cleaning and put in the new gaskets. I'll just make sure they know about the mods

 

cleaning and rebuilding are 2 different things as rebuilt requires replacement of the shaft bearings.

 

any updates here???