My2nd 69 442

I'm looking for recommendations as to the best, most informative with best illustrations for my original Rochester Quadrajet (7029253) carb.
What do you carb experts recommend.
Also , the numbers below the P/N is 1723 with no letters.
Can anyone de code this for me, I haven't found any info for that #
Thanks,
Jerry

Fun71

There are two very good books, one by Doug Roe and the other by Cliff Ruggles. I would get both of them.

Doug Roe: https://www.amazon.com/Rochester-Car.../dp/0895863014

Cliff Ruggles: https://www.amazon.com/Rebuild-Modif.../dp/1932494189

My2nd 69 442

Thanks Kenneth.
I need a little work on my Original Quadrajet(7029253). The car has a tendency to die at stop lights when hot otherwise it runs great.
Any help will be greatly appreciated while I wait for the manuals you suggest. Idle 750-800.
Thanks
Jerry

joe_padavano

Chapter 6M of your factory Chassis Service Manual is the best source for information on your original carb.

Fun71

When it dies, is it sudden or is there any warning?
Does this happen as you're slowing to a stop or after you have stopped?

My2nd 69 442

In general it happens after stop while awaiting light change. Black smoke on start clears up quickly exhaust tips very black. I have not pulled plugs yet. Gas mileage appears terrible

Jerry

oldcutlass

Look down into carb when its idling and see if the fuel is dribbling. If not then I'd go through all the tune settings after pulling, cleaning or replacing the plugs.

My2nd 69 442

Thanks guys. You folks are great. I've been kinda waiting for the new to wear off before I take anything apart. I'll probably get around to it maybe next week.
I really do appreciate your opinions and advice especially since I'm a new guy around and haven't contributed anything.
Jerry

Fun71

I wonder if it's flooding out. Do you know if the fuel pump has been replaced recently? I had a string of new pumps that put out too much pressure and caused flooding.

My2nd 69 442

Kenneth, Right now I can not answer your question regarding the fuel pump. Today I did pull the plugs and all looked pretty good. orange/gray ash color. Gap was a little excessive at .045 I reset to .030. I did not see fuel dripping into the carb at idle.
I was gonna check timing but my son has my setback timing lite. He says he will return it Wed. Non setback was off scale BTDC. Vac on no vac advance. Also found vac advance NOT connected to carb. It is connected to manifold at rear of carb. Car runs great off idle and going thru gears and at cruise
Jerry

My2nd 69 442

After looking around at the Fuel Pump, it looks as if it may have been changed in the not to distance past. Any idea where I might find the part number or date code on the pump?
I'm trying to find and correct all or at least some of the minor issues as I discover more about this car. I really appreciate all the advice and comments coming from this site

cjsdad

Stumble and die at idle sounds like it could be a bad PCV valve. While not a definitive test, if you take it out and give it a shake it should rattle. If not, it is probably bad and may be causing a massive vacuum leak. One of the least expensive things to check first!

BTW, being new or not contributing yet does not mean we won't help you any way we can. It just means you haven't had time to help someone else yet.

Fun71

What type of distributor is on the engine - points or HEI? The timing tab goes to 14º so the initial for an HEI will be way off the tab.

quaddriver

I was curious who bought all the olds manuals I had at carlisle 2 years ago...now I know....

wanna sell me back the 78 one? ;-)

My2nd 69 442

It has a HEI that PO had installed and said it was re-curved. He gave me the original springs. What should hei be timed at? Initial and 3000-3500 rpm

Fun71

Well, since it has been recurved the initial may not be anywhere near factory. Initial is just total minus mechanical, so check the total advance at ~3500, record that, then see what it reads at idle. That will be your initial setting.

My2nd 69 442

Checked timing this morning as follows: Vac disconnected and plugged 23* at 850 rpm
37* at 3500 rpm
Vac connected 25 @ 890 rpm and 47* at 3500 rpm
No other adjustments made to carb during either check
Seems to me that with vac hooked that 47* is considerably high
What do you guys think. Should I leave vac disconnected and see how it runs or leave vac connected and readjust timing to ?
Thanks for your suggestions

Fun71

From what I have read over the years, most GM HEIs have ~20º initial and ~14º mechanical for 34º total. Sounds as if yours is bumped up 3º over that, which shouldn't be an issue as long as the engine cranks easily and there's no pinging.

As for the vacuum advance, the 1977 403 distributor in my car originally had a vacuum canister that gave 24º advance. Yours sounds as if it's giving 10º which is what most folks shoot for when modifying the factory canister. I would leave it as is.

My2nd 69 442

Thanks Kenneth, I value your opinion.
I just now completed a compression check, results as follows: #1=145, #3=148 #5=148, #7=148 #2=148, #4=145, #6=150, #8=148
Results look good to me. What do you think. What do you guys feel my plug gap should be set at.
Decal on car says .030 and AC web site says .044. Plugs are R 45 S I run my Camaro at .045 ( same plugs) High compression eng with lots of power goodies.
I have found another item that may be of concern. The Dashpot shown in the CSM on page 476 in diagram 14 does not come close the the carb linkage and the CSM says to adjust to within .060 of linkage. The rounded end appears to be broken off. Could this be part of my problem?
Others are very welcome to offer their opinion also

My2nd 69 442

cjsdad. There is no pvc valve installed. The PO has installed chrome eddy valve covers with a breather type filter in each cover. I plan on reinstalling the stock valve covers. I will install pic valve then

Fun71

I think you can run either of those gaps with no issues.
I gap my plugs at .045" with the HEI.

My2nd 69 442

I ended up gapping the plugs to .044 as per the AC/Delco site. I'll run this gap awhile the take a look at the plugs again.
Do you have any opinion on the "dashpot" issue I have discribed. I have not been able to locate a new part for it as of yet. I'm trying to keep everthing as original as possible.
Thanks Kenneth for your help. If you ever make it down to Tucson, please let me know and I'll buy a beer(or several)