QuadraJet questions

[Ornery37]

I have spent several hours searching and I have found every vacuum port except these two. I bought this as a reman. do not know the year. I have 5 ports in front, 3 on the rear, and then the large one off the canister/diaphragm. #1 top center rear and #2 the one off the canister/diaphragm.
any help appreciated

[Gumby]

any help?

[Ornery37]

Hey Gumby, yes some, #7 I am assuming that goes to the charcol canister that I have been reading about so I can cap it off?

[Gumby]

#4 is the charcal canister/canister purge, #7 is vacuum resivor, funky round black orb on some rides, it can be capped off. [think its there to hold some vacuum for the HVAC controls, the orb that is]

[Ornery37]

thankyou so very much! now I just have to figure out the secondary diaphragm? with the large port on the rear. Cause it already has the small port on the side that goes to the back of the carb.

[Gumby]

well pics are all of BOP qjets, so its only abour 98% the same.

[Ornery37]

passenger side of the carb
#1 points to the electric choke
#2 points to the (secondary choke diaphragm?) and the connection from the side of it to the bottom of the carb.

but this (#3) is the only (secondary choke diaphragm?) "thing-a-ma-gig" that has a large hose fitting off the back.

[Ornery37]

did some more searching and the assembly circled in the post above, some are calling "choke pull off" others are calling it a "choke vacuum diaphragm". but no explanation why the one on mine has the small port that goes to the bottom of the carb and the large one off the rear of the (that I have plugged right now in the smaller circle #3)

[Ornery37]

o.k., I think I found it, but I need to get a mirror tomorrow to look. In that large tube/port off the back of the Vacuum break diaphragm might be the adjustment screw/allen.
Found this pic.

[truckster]

You are correct. The diaphragm is a vacuum break (or choke pull-off) and the adjustment is in the center of the back.

[Ornery37]

New problem, this plate? Block off? By the front passenger bolt is spraying gas when I rev the engine. What is it and what can I do to keep it from spraying? The shining quarter thing?
Posted via Mobile Device

[Gumby]

I don't know but isn't that the spot the plug would go for one of them electronic qjet carbs???

[never had one]

[Gumby]

yep here is a pic



and im 90% sure they don't work right without that thingy working, can't just unplug it and go like a reg carb.

you got the wrong carb by mistake or the info you gave them said you needed that.



pic also show its has a TPS

[Gumby]

Here is where I got mine, pics above is it, for my Buick, came set up ready to roll, just bolted on and went. even with a core charge, you could resell their work for a profit.

http://www.nationalcarburetors.com/

[morcey2]

Originally Posted by Ornery37

New problem, this plate? Block off? By the front passenger bolt is spraying gas when I rev the engine. What is it and what can I do to keep it from spraying? The shining quarter thing?
Posted via Mobile Device

That's the spot for the dual-capacity accelerator pump solenoid. (M4MED is the q-jet model) My guess is that with the solenoid and other parts pulled out, the accelerator pump shot is hitting the block-off plate and spraying everywhere. It can't be blocked off like the mixture control solenoid, which happens to be in the same spot and have the same footprint. If you compare the bowl-vent tower at the front of the choke tower on your carb with Gumby's pictures of the computer controlled carbs, you'll see a difference. Plus, there isn't a spot for the throttle position sensor on your carb.

My guess is that there is a passage in the bottom of the bowl that can be plugged to get the pump shot to stay where it's supposed to. If you can get the inner-workings for the solenoid and re-install it, just leave it unplugged and it will function just like a normal accelerator pump circuit.

Also, the top vacuum port at the back of the carb (#1 in the first picture in the thread) is not a vacuum connection at all, but a filtered air connection for the EGR bleed solenoid. There should be no vacuum on that port.

My 85 K10 came from the factory with a M4MED, originally carb # 17085230, but had a generic remanufactured carb that has a leaky fuel bowl. I can send you the guts of this one if you want to try to put them in. PM me your address if you want them and I'll throw it in the mail tomorrow. It's not doing me any good sitting in my garage gathering dust. It's not a lot of dust as I just barely pulled it apart.

ETA: If you bought this as a new remanufactured carb from a retailer, take it back. It won't work with that block-off plate. If it was used or off someone claiming it was remanufactured, there might not be much you can do at this point.

Matt

[Ornery37]

thanks all, this is all very helpful, I got it from Summit a couple of years ago for another project that did not happen. I do not know if I have the bill, to return it.
mine does not have the TPS or even a spot for it, could the body be swapped with a different one also?

Yes, that would be great, Morcey2 I will send you my address.

[morcey2]

I'll get it sent out tomorrow. If for some reason you don't hear from me in the next day or two, send me another PM. As much as I love the extra fishing time after work from daylight savings time, it makes me forget stuff because of sleep deprivation for the first week or so.

Matt

[Ornery37]

Hey Matt, no problem. I am in no hurry, I am all in for enjoying life when chances are given. Thanks again.

[Ornery37]

Gumby, that national carburetors site is cool. Thanks, will see if I can repair the one I have first, my truck fund is almost empty. Need to start selling stuff again, so the wife cannot trace what I have spend on the truck.