hard start problem

[Tom S.]

I am still having a hard start problem. It is a problem after the car sits for just a day or overnight. It is a 350 with a brand new out of the box q-jet carb. The problem started after I installed the new carb.I have checked for Vacuum leaks, replaced the mounting gasket, checked the choke over several times,everything is o.k. Now if I pour a little gas down the throat of the carb it pops right off.After asking around several people have said the well plugs in the carb are leaking.Would this be likely on a brand new carb? And if so what is the best fix. I've had a couple guy's tell me to pull the carb and put some J-B weld over the well plugs. Is this an acceptible fix to the problem?Thanks in advance.

Tom Stanton #41491

[Scott Butville]

Re: hard start problem

Sounds correct to me. If you want to make sure, pull the carb after shutting off the engine and set it over a dish to see if the bowls drain.

[Roy B.]

Re: hard start problem

Scott is right and your friends is right.

[Joe M.]

Re: hard start problem

I recall an article way back when about porous castings in the Carter WCFB around 1969....Hot Rod Magazine???. I actually experienced this on a stock 69 vette, 350/300. Pulled the carb, filled the wells and sure enough it seemed to seep thru the walls. Replaced it with a direct replacement holley and all was well.

[Tom S.]

Re: hard start problem

Joe
This is a Rochester q-jet carb. part # 7029207. I had an incorrect holly on the car when I bought it, and it leaked internaly, overfueled terrible.This one is brand new and the correct part # for a 350/350, runs perfect after you finally get it started.Thanks for all the input everyone. I will pull the carb this weekend.

Tom

[Joe M.]

Re: hard start problem

Sorry, I meant Quadrajet. Surprisingly, this article spoke of the Qjet castings made by Carter. Sure enough my walls were porous.
Ran great but if it sat overnight I had to pump the pedal.
While searching for this article I came across a number of early 70s Qjet rebuild and tuning articles if your interested. Some of the issues already mentioned with loose plugs were also noted as problems in these articles.

[Tom S.]

Re: hard start problem

Joe
I appreciate your help and would like to hear more about the articles you have. I took the carb off and don't find plugs as such. What I am geussing are the plugs are the soldered plugs on the end of the 2 copper tubes?Would I just put the J-B weld on the end of these?By the way I put the carb over a bowl all night and didn't find any gas in the bowl this morning.I am not sure now what my problem is. Thanks again.

Tom

[Tom S.]

Re: hard start problem

Scott
I pulled the carb and put it over a bowl as you suggested. I found no gas in the bowl after sitting all night. It did appear to me that the gasket between the carb base and the body of the carb itself was awful wet.It is a cork gasket but it doesn't seem that it would be wet on the outside. Like I said before, it is a brand new carb not a rebuilt so I didn't expect anything like this.Any thought's or help will be appreciated.

Tom

[Joe M.]

Re: hard start problem

Tom,

Contact me with your address and I'll copy the articles for you. In the meantime, check to see if Delco or Tomco still offer the replacement plugs mentioned below.

Here is an excerpt from, Supertuning Rochester's Quadrajet/ Poular Hot Rodding, 197?.
" some q-jets have a plug at the side of the fuel inlet which has a habit of leaking or falling out. It can be replaced by Tomco's BOL plug, which is fitted with an o-ring. Push in and stake casting."

Also, 'Super Carb for Chevys'.....Rod Ideas/ 1972

Paraphrased...."Delco has a kit to hold core plugs in place. There have been many instances of core plugs falling out...... Another of the plugs will dump fuel on the engine....Carb cleaner tends to loosen these plugs...."

Hot Rod/ 1971.......'Answer to a Prayer'.....Holley's "new carb",4165, is a direct replacement for OEM Q-jet powered chevys....
This is what I did to an absolutely stock 350/300 69 vette. Gave the original carb to the guy who eventually bought the car.

Epoxies are wonderful, I'm sure you can satisfactorily use any of several available but I cannot make a recomendation. Dad used to work on small engines and he made a believer out of me when he used J&B on a cracked aluminum block for a wood chipper. Another off brand epoxy held my aluminum radiator together for 11 years until I found a better one.

If one plug leaks I'll bet the others are not far behind. I'd be very conservative in my approach to resolving a fuel leak.

[Tom S.]

Re: hard start problem

Joe
Thanks for your help and info. I think i might try the Holley route, and save the # matching carb for the next owner.Mine is very similar to yours, its a 69 L-46 I think the #'s were only a couple apart on the carbs. Thanks again.

Tom