Starfox07

I think you misunderstood my post.

craaaazzy

iTrader: (9)

Have u resolved ur electrical issue yet? If not, have u taken ur alternator to get it tested at least?

j_tso

iTrader: (2)

I think you're hearing the fuel being sucked/pumped down the jets rather than air. Are you hearing the pump jets squirt against the back of the manifold?
It's a really fine stream of fuel, so it's not surprising you're not hearing it until a quarter turn. If you take it off the manifold and turn the lever, the stream should shoot a few feet.

Starfox07

UPDATE:

I am happy to report, that after leaving the car to sit for a number of months, I actually did something about the problem!

I replaced the battery which made things much easier, as I'm not having to both charge the battery constantly and try to tune a italian carb.

Here's what I did. I decided to say **** the racing beat recommended specs on the accelerator pump adjustment, and just unscrewed the thing all the way. Result: Instant gratification. The engine no longer stumbles on quick throttle applications, it just revs. It isn't perfect yet, but I was able to drive it! The jetting feels pretty solid. The car pulls cleanly from idle to 2,500rpm and from 4,000rpm to as high as I dare. Mid range is wacked out, but I'll get to that. The car feels more powerful than before, but not as much as I was expecting. Seems to run out of puff at 6,000rpm, so I think it's going rich on the top end. More fuel and ignition tuning to come. Aux ports are completely gone.

I have to say, at this early stage, I'm extremely pleased.

Even with the tune not really on the money yet, the drivability is not much worse than the factory EFI setup, and it actually idles much better. But that isn't why I did the swap, I did the swap for three reasons, and all three of those revealed their magic today.

1. Power. While I still feel there is more to come, it's definitely got more poke than the EGI. I actually spun the tires going into 2nd gear on 205 section dunlop direzzas. I could never do this before, even on crap 195 section all season tires.

2. Response. It's just electric. I love it. Instant communication between the engine and my right foot. No electronic committee or delay of any kind. Just power on demand.

3. Sound. It sounds exactly like I was hoping it would. ******* fantastic. No injection setup short of an ITB sounds this good. I'm not sure if it's just luck or careful subconscious planning, but the intake and exhaust are almost exactly the same volume, so I get a perfect mix of both in the cabin. It sounds so enraged. When I was doing the test drive today, I couldn't stop downshifting, just to hear those velocity stacks bark.

Not to mention the carb setup looks way better than the EGI did, and probably shed close to 50lbs (more if you include emissions) worth of clutter. All in all, I am quite pleased with the Dellorto 48 conversion, and I am eager to tune it even better.

I must warn anyone considering this, you must be patient. And have a daily driver. I shall try to get some videos soon.

Starfox07

Just thought of something today. As per most instructions I've found, the idle mixture screws should be 'three turns in'

Now, does this mean I screw them all the way tight (clockwise) and then unscrew them three turns, or the opposite?

j9fd3s

iTrader: (3)

three turns out. be gentle when you tighten the screws, the needle is easily bent/damaged. on the IDA you can do it by hand.

3 turns out is meant as a generic starting point, so then you should adjust in half turn increments until the engine is happiest. if you have to turn it more than a turn, its telling you it wants a different idle jet.

Starfox07

To be honest, I can't really tell much of a difference when I'm turning them. I suppose I should listen more carefully.

Also, does the idle mixture screws have input on the engine after 4,000rpm? I'm trying to figure out why the power drops off after 6,000rpm. I would think it should pull harder up there than before. I'm going to do a basic tune up, new fuel filter and new plugs, and see if that helps. I haven't touched the plugs in probably 4-5 years, so I'm sure replacing them would do some good.

j9fd3s

iTrader: (3)

the idle mixture screws only effect the idle mixture, and its actually possible that if the throttle plates are too far open, they aren't even working at idle.

new plugs, and at least checking the carp rotor and wires are a good first step.

Starfox07

I've ordered some new plugs, hopefully they'll be here by saturday.

I did a little more tuning today, and while the car doesn't behave well when cold, it operates nearly as well as the EFI did when it's warm. I'm pretty impressed. I'm still having some gremlins with low-medium load throttle applications in the 2500-4000rpm range. Tends to buck a little bit. Any advice?

WOT works great from idle to redline. Just pulls smooth and [relatively] strong. It feels far healthier in the mid range than the factory setup, but it just seems to fall down on top end. I'm hoping its ignition related. If it isn't, what are some things I could do/look at? I think the fuel is pretty much right on the money, if I let off after pulling to 7,000rpm I get some popping and a little burbling, but no giant backfires or ***** of flames.

I still can't get over the sound. It's addicting. Braaaaaaaaaaap!

j9fd3s

iTrader: (3)

it sounds like the main fuel jet is are about right, as it works @wot, but since it stumbles in the midrange its an idle jet/etube/air corrector issue.

the idle hole idles the car, then the idle jet needs to run the engine until the main circuit starts working, so maybe the idle jet is off, the etube isn't "fast" enough, or it wants a smaller air corrector.

its a carb, write down the jets you have and start playing with it

Starfox07

I've started thinking my timing might be to blame.

This is in the RB installation instructions:
I interpret that as simply take the hoses off the vacuum advance diaphragms and leave it alone. Am I mistaken? From the factory, is the leading 5° ATC and the trailing 20° ATC? Or am I supposed to adjust it to those specs? I never set the timing on the car, and I'm not really even sure how. Help!

Siraniko

iTrader: (13)

Just like the starter, carb is a two-step process. Idle jet is from idle to approx 2500 RPM, then main jet will kick in. I always keep at least a 50 increment between main and air jets to keep it rich on top end (ie, 150 air, 200 main).
stumble at mid range around 6000 RPM, in my experience, is a spark plug wire issue. for some reasons, magnecor doesnt play well with MSD. Solved my issues 10 years ago when I switched back to NGK blue wires.

timing wise, 25/15above 4K RPM is still conservative but works well

Siraniko

iTrader: (13)

Starfox07

I apologize, but can you explain this bit a little more. I'm truly clueless when it comes to ignition/timing.

Starfox07

Anyone?

Siraniko

iTrader: (13)

set your timing at 25 leading and 15 trailing at 4K RPM. in order to to this, adjust the idle screw until youre at 4K RPM or have a friend step on the gas pedal. I didnt read the whole thread but you need to mark the timing pulley. If you have not, search under Paul Yaw on how to add timing marks to a stock pulley

Starfox07

So if the ignition timing is stock right now, what is my current timing above 4k rpm?

Siraniko

iTrader: (13)

10 and 0 at idle will you close to 25 and 15. hook up your timing light and see what happens. but again, you need to mark your pulley to make sure as most peeps get into trouble with guesstimate. dont be afraid to try different configuration (timing and jetting and such) to find what works best for you.

Rotary-MG

iTrader: (1)

http://www.racingbeat.com/manuals/timingchart.pdf

just a little chart
I was astonished at how much the timing can vary depending on setup.

Starfox07

So according to that, my timing should be fine.

Next up: Cap, Rotor, and Plugs.

Starfox07

Cleaned the cap, rotor, and plugs and it didn't seem to make any difference.

Current thoughts:
Bad ignitor (would it run at all?)
Bad coil (would it run at all?)
Main jet is too rich.
Main jet is too lean.
Timing is off (how?)

I took a video with several 2nd and 3rd gear pulls. You can see it's just not wanting to pull past 5,000rpm with any sort of gusto.

[youtube link]

EDIT:
Just had a thought, and confirmed it. My throttle setup is less than ideal, and with the current geometry, it's only allowing the throttle to be opened about 3/4 of the way. Time to fix this ****.

Starfox07

Anyways, here is the vid.

Starfox07

What do you guys think about this throttle linkage kit?



I really like how it works, but I'm concerned about the cable pull direction. From the factory, the throttle cable pulls from the driver side, and this one would be reversed, pulling from the passenger side. This doesn't concern me except for the fact that the cable supplied is 1450mm or 57 inches long. Is that enough to emerge from the firewall on the driver side, go all the way to the passenger side, loop around, and then be connected to the carb linkage?

Here is the full details:
Dellorto and weber carburettors online

Just made a mockup with some twine and it's easily long enough, so I ordered it. Should make my setup look even cooler.

Starfox07

The linkage came much faster than I expected. I mounted it, but ran out of daylight while hassling with innane factory throttle cable. Hopefully I can finish the setup tomorrow.

The linkage is beautifully made and feels absolutely wonderful on hand twists. I can't wait to see how it feels with the throttle pedal!

It wasn't cheap ($150 shipped) but it's rare that I come across an aftermarket part that feels such high quality. A+++

j_tso

iTrader: (2)

As long as there are no sharp bends, the cable should be fine. I've got the Webcon linkage that has the cable coming out of the side, and with my new set up the cable does an S shaped bend, but it works smoothly.

It's almost the same price, but the throttle feel is excellent, and there's no need to jimmy rig some return spring.