Thread: Qjet vacs #2 - Denny or Techinspector?

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I know I have been asking alot of questions. My engine swap/refresh has lasted for 2 years and I still am not where I want to be. I want you guys to know I very much appreciate the help and I am not a moron, I am LEARNING.

My previous attempt at a Qjet failed (bad carb, see other post), so I bought a Jet performance Stage 2 carb. Looks very nicely done and I figured it was about as close as I can get to a sure thing. I want to MAKE SURE I have them right before running the Jeep, so I am looking for input. I ONLY need PCV, Dist (ported) and auto tranny. The Rochester book I have is not clear on this issue.

I numbered the vac ports in the pictures:
1) ??unused
2) PCV
3) Ported vac for my dist (as recommend by Jet)
4) ??unused or auto tranny
5)Big - full manifold, unused
5)small - ??unused
6) ??unused or auto tranny

Thanks in advance

First four numbers in your serial number is 1708 I pressume? I can tell you you where each goes but I'll let Denny or Tech answer. I have a dozen of these things sitting on the shelf (Irritates the wife). Good workable unit for your set up.

Pnut....do you feel confident in this carb?........as long as doesn't give you the past grief you suffered with the older one, Keep testing ang tuning....it's just gonna get better.

By the way, I agree, good pics!

Thanks guys. By the way, I did not intend that Techinspector or Denny were the only ones who could answer.

I am using full manifold vac for brake booster (a fitting directly on manifold). Is there any reason why I should switch to the carb port (planned to plug the carb one, brakes work great on direct manifold)?

Why would I use the high speed crancake draw port? I can't think why I would use that.

Finally, I noticed another port just below the fuel inlet you can see in the first picture (passenger side low). What is that for?

you dont have to use the high speed crankcase vent port, but the reason it is there would be to keep keep oil from coming out your breather and getting all over your valve cover/exhaust

Thanks guys for the info, I understand now. If I have any breather spitting, I will switch the PVC to that port 6.

I started up the engine with this new carb and WOW what a nice difference. It ran great for 10 mins. I set the cold and hot idle and let it run in. I got no stumbling when pushing pedal quickly to the floor. Couldn't drive it right now due to snow here. Few more questions:

- On the port above the fuel inlet where dist was hooked to gives full vac at idle. If I want ported vac for dist, I need to choose another port, correct? Ported is no or little vac at idle and increasing with more load/rpm if I've got it right.

- I think my vac advance on the dist is not working. I disconnected the dist, plugged the port, and the timing was 8-10 degrees. I plugged it back in and the timing was the same. Remember that this port was pulling max vac at idle. I have lightest springs on my dist if that matters. hmmmm

- With the vaccum gauge hooked up, I turned each of the idle mixture screws in until stumble and then back out enough for smooth idle (about 2.5 turns). But the vac gauge hardly changed when I did this. I understood that I should dial in idle mixture using vacuum gauge? Maybe I should not use the port above the fuel inlet?

- I'm still running quite rich based on the super rich exhaust when I goose it. The gas has stabilizer in it, but is still 6 months old, plus the engine has been running on and off for carb tune all winter. I'm guessing I should run it as is, drive it around for 10-20 minutes, fill with fresh gas, and then see if it running rich after that. If I still get rich then, I'm thinking I have to reduce the jet size.

and thats why i have fords with holleys.... too many blasted vacuum lines on that thing!!