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Ned's 7K Drop Hatch Starlet


Ned

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OK, so the giant air hole stops the slide from creating a vacuum and lifting the needle. Dave said he saw the slides lift when I revs it yesterday but maybe they don't go up big enough.

I checked the diaphragm for holes and its legis, so that's probably it. Will try blocking them off now :-)

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is that video just a guy talking with a low resolution picture up thats hard to make sense of? because thats all i get...?

so it appears to run better at idle, but rich as all buggery. (AFR of ~10)

mid range is good, go doorting at 1/2 throttle or so and get 13-13.5 ish?

top end is still poos. Went foot flat doorting and was still lean. Would start off ok, but work its way up to 18-20 pretty quick.

though maybe it needs more fuel pressure, so upped the pressure out the reg, and thats now at 3-4 at a guess, up from 2 i had it at before.

The wideband doesnt give me back any steady readings, is this normal? first time using one and nobody else has looked at it, so unsure if it's normal.

It'll fluctuate quite a bit (around 1 i guess?) and goes mad off the chart lean for a bit when backing of the throttle.

The fluctuating readings are probably from the slides vibrating, they dont move nicely, they vibrate quite a bit. Still go up and down, but vibrate up and down a little at whatever level they are at. They appear to go all the way up though when static revving (the only time i can see them)

re: emulsion tube, from my understanding (which is based on a couple articles i read)

So the emulsion tube has a few holes in it, and the needle slides in the top, and the main jet goes in the bottom. When the butterfly opens, it creates a vacuum up the top of diaphragm and pulls the slide up, which pulls the needle up, which lets more gas out as the needle is tapered. With low throttle, it uses little fuel, and most the holes in the emulsion tube are under the fuel line, and the holes at the top are open and will let some air through, and let it run leaner, the more holes are there. When dooring at 1/2 throttle, the fuel level is lower because it uses more fuel, and opens more holes for that ranges rich/lean setting. Full throttle doorts will lower the fuel level enough to unblock the lower holes, and let them dictate the rich/lean ratio for that range? is that right? or did i get that wrong?

Now with my regulator, if i set it too high, the level will sit higher because it pumps in more fuel/quicker etc and with a lower pressure, it will let it run the fuel level down faster, and not refil it as quick? So the fuel pressure will have a huge infuence on the operation of the emulsion jet? Though if anything, it would make it run richer at full doort with more pressure because more holes are covered right?

So long story short, it's still lean up top, and i dont know how to fix it.... The slides vibrate, which is probably due to lack of air box?

I'll take a couple more suggestions before giving up. I wanna get to nats! car or no car, i dont care anymore

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Guest shaneo

Move the needle jets down one clip that will give it a little more gas but a little rich is safer. When are you leaving I'm going in about an hour ? I have quite a lot of jet drills as well if you need them tomorrow what are you at the moment?

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The needles are all the way up, aka as rich as they can get already.

I'm not leaving for a while, still havent packed and all my clothes are dirty from working on the car all weekend. IF i leave tonight, it will be late, like 9-11pm but i doubt i'll bother. I'll probably go tomorrow morning, and try find a throttle cable for my original carb tonight. If that fails, i'll take the LS.

I have jet drills, but i dont think thatst he problem, unless the other jets need to be drilled out also, but the interweb says that just the main jet is responsible for full throttle doorts....?

Putting a filter on should in theory make it richer. May try making an air box out of cardboard or something and seeing if that makes a difference. Dont have a huge amount of room for filters... might go to repco now and see if they have anything though.

pic just because....

IMG_20130411_171751.jpg

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yeh maybe ur regulator is being too regualty. not enough fuel flows. lines up with your increasing afr with prolonged wot. I drank lots of beer

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Guest sentra
Dave said he saw the slides lift when I revs it yesterday but maybe they don't go up big enough.

for your reference, they definatly pin out

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  • 4 weeks later...

It's not, but i got called up and asked if i wanted mine to be in it. Was quite keen but for some reason they never called back. Pretty sure he wasnt too keen as mine was lowered or something and didnt have carpet etc

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