75 carb choke issues - componet ID help

[crossy]

I need a little ID help here. it's been way too long since i have been under the hood of anything that is mid seventies STOCK. The emissions crap from these years is confusing. I used paint program to number the componets and I know the EGR port is broken off so that's non functional, but this carb is new and correct year, but i can't get the choke to stay on after initial fire up. Nothing is worse to stay running than a NON choked QJ carb. I see the choke pull off work, but need to pinpoint the problem and need to know what the componets are before i proceed.
please help me ID the pieces by the number.
Don't bother if your just going to say i need to trash the QJ- it's staying.
Thanx, crossy

[James McClure]

Crossy. 1,2 & 5, no clue as to purpose. 3 is secondary choke pull off, 4 is choke primary pull off. Your problem with eng shutting down after cold start is easy to fix IF, the engine runs well after it's warm. First, open throttle a little bit and close the choke all the way and then let go of the throttle and then the choke butterfly. This sets the fast idle cam and will allow the choke plate to travel full range. It should, at this point stay shut and have some extra pressure holding it shut from the choke coil. Now, don't touch the choke or the throttle. Push the primary choke pull off (4) all the way in. It should pull the choke open about 1/4". The screw on the pull off is the adjustment. Unscrew direction will open the choke further, screwing it in will close it. If choke feels "soft" or doesn't close all the way, loosen the 3 screws on the choke stat cover until the hold down clips are loose. With your screwdriver handle tap the cover lightly to get it to come loose. Do not remove cover. Rotate cover clockwise a little at a time until choke plate is shut and then rotate it another 1/4 to 3/8". Screw the cover screws back in making sure the retaining clips are properly positioned. Next set high idle. There is a screw underneath the choke stat housing that rides on a cam connected to the choke linkage. You can see the cam from above. It MUST be in the full up position to set. Now warm the eng up. If it stays running WITHOUT HITTING THE GAS, great, set high idle at 1500 RPM. If it won't stay running, keep it going with your foot until it will idle on it's own and is warmed up. Shut the eng off and set the choke as I said above (this will raise the fast idle cam into position) Without touching gas, restart the eng and set fast idle. Kick her down and set curb idle to about 700 RPM in gear (auto trans) and about 800 RPM for a stick. I've rebuilt hundreds of QJ's and love them. My truck is nearing 500,000 miles and Iv'e done mine 4 times now and it still works well. They are a great carb. Let us know how you do, jim

[Jonboy]

Does it have a TH400? 1, 2, or 5 may be the electric kickdown for that. Is that a Pontiac engine?

[Restrorob]

James,

That has to be among the best write-ups I've seen, Kudos to you !

[crossy]

@jonboy, It's factory 454 in a 75 with TH400. thanx James. I know more than the average guy about QJ's and fixing the well leaks and getting rid of the secondary bog, and turning the choke plate, but I never had the explanantion explained that well. I'm a little foggy on some of it and being from NY you know the weather is no help here right now. I havea spare 73 or 74 QJ in the warm basement so i'll go through things on one of those before i venture underhood on the 75. I knew #4 was the choke pull off , but had no idea that #3 was also. NONE of the many other Qj's i've owned had #3. even my spare 75 carb. And yes it idles fine once hot. thanx again. crossy

[James McClure]

Thankyou gentelmen for the compliments, they are appreciated. I have always figured it's better to have more info than I need to attack a problem, so that's the way I explain fixes to others. I do tend to get a little long winded sometimes though. Also I have to give back. I was a mechanic for 33 years and was trained by other mechanics and by GM so it's thier knowledge that you get with a little of mine mixed in. If I know the answer I'll tell ya, if I don't, I am smart enought to keep my pie hole shut, LOLL. Have a great day guys & will someone plow my driveway? We have 2 feet of snow on the ground here. jim

[crossy]

It will even run for a minute or two before it shuts down , on it’s own, which is really what confused me. Since I have never seen a second pull-off, and I thought I had the primary one set right, then I have to assume it is the secondary one that is pulling the choke plate open after a few minutes. Of course the engine is not warm enough to operate w/o it yet at that point and it will NOT reset again. I will go over everything you said , but it won’t be this weekend. Supposed to be in the Teens all weekend. Thanx , crossy

[James McClure]

Crossy: My good fellow, read what you just wrote above and think about it for a minute, do you see what I see? You just answered your own question but don't know it, YET. You say your truck will start and run "for a minute or two" before it quits Hum, Hum, Hum. OK, ask yourself if the choke butterfly is open or partly open when it stalls out, if it is, tighten the chokestat a bit to close the choke more positivly and try it again making sure to set the choke as I explained above before you try to adjust the stat. If you don't the choke won't close as you make the adjustment. #3 or secondary choke pull is adjusted by opening or closing the bend in the linkage that drops down just in front of the pulls plunger. A crude adjustment to be sure, but it works. Opening the bend will allow the choke to close further, closing the bend does the opposite. In the teens?? Thats warm. Up here it was -5 last night and tonight it's supposed to go down to -15 or colder. Thats cold enough to freeze a dead witches tit in a brass bra or the balls of a pawn shop. LOL Keep in touch on this issue, jim