Rebuilt Qjet won't start or stay running

[tayto]

Rebuilt a 1980 Pontaic Firebird 301 Q-jet #14080272 with one of Cliff's kits this fall, but didn't get a chance to attempt a start up until this weekend. I manually sucked fuel up to the carb with a hand held vac pump and poured fuel down the bowl vent multiple times to get it to run. It would start but would only stay running if I pour a constant supply of fuel down the throttle body. The car ran when the carb was originally pulled a year ago so I think timing should be "close enough". I didn't think to verify to see if the pump was actually pumping before the battery died however. We replaced the carb and carb spacer gasket that is specific to the 301. We ditched the EGR valve as it was non-functioning plus the fact the local parts supplier wanted $150 for a new one. I made a block off plate out of 3/8" steel and put on a fresh gasket. Replaced all the vacuum lines, omitting some circuits for devices that were no longer installed in the car. Also replaced the grommets in the valve covers, as well as the PCV valve and its' grommet. This carb was pretty warped upon initial removal. I made my own plates and straightened the air horn and main body as best I could. I used Cliff's thicker airhorn gasket and once everything was screwed down and torque to spec it seemed to fit really well together. I have the carb pulled already so I will have to inspect the impressions on the gasket to make sure everything is sealing OK... I set float to 21/64" as per factory literature. I'm thinking when I have it open again I might set it to 1/4"? I also ditched the spring on the seat. I'm thinking maybe  the needle and seat could be damaged? If I vac tested it, how long should it hold a vacuum for, and is it alright if it drops during that time provided it doesn't drop to zero? Or should it hold 15 in-hg steady for 10 minutes if that is what I apply to it? Well plugs were tested with compressed air and soapy water, no bubbles. When carb was installed in the fall no fuel was left in it, so I don't think it has any varnish in it. I also cleaned it with an ultrasonic cleaner, small diameter steel wire and lots of carb cleaner, the thing was spotless.

Any ideas on where to start?

[429bbf]

don't laugh or get mad . but id start simple . gas in tank, any fuel coming to the carb from the fuel line , plugged filter.once them are confirmed . then id take the carb back off . fwiw

[tayto]

After I charged the battery I confirmed the fuel pump does indeed pump. Didn't have a gauge but it seemed to have a very powerful stream. I bent up a new hardline, needs to be test fitted though. I took the air horn off the carb, no debris in the bowl (good). I also checked the float... calls for .328" but it was set closer to .400"!! Would this cause a no idle condition, ie: flooding?

[tayto]

Sorry, with the float set lower it wouldn't cause flooding but a LACK of fuel delivery, correct?

[blazer74]

If your sure you have fuel supply to the carb and no restriction at the inlet filter. If you have the black check valve backwards in the filter that could be a problem if  you have one installed.
Even though all the kits I've gotten from Cliff didn't have one in the filter.

If you removed the needle spring and let the carb sit for a while the needle could be stuck. One of the purposes of the spring is to allow the float to pull the needle up to allow fuel in.

just a thought. Good luck.

[tayto]

No check valve in the filter. I talked to Cliff yesterday and he suggested the same thing about the clip that goes between the needle and float arm. I omitted mine as per Cliff's book.  Of course I've lost the one that came with the kit and threw out the old one.  Going to one from a donor carb this weekend. I also had the float set right, factory spec is 15/32", not sure where I got the 21/64" measurement from...

[blazer74]

Not a big diff between 21/64 and 11/32,  would have been fine. little higher than the 15/32 setting. The needle should be fine without the clip if you drive daily or so. Should take some time for it to get stuck. I always use the clip though.

21/64 might be the choke break setting you saw.

[429bbf]

fwiw my pickup was only setting for 2 weeks went to start it today and would not start. dumped a little gas in carb . fired and died .did this three times . still won't stay running. i have a short piece of hose going to carb . i could feel it had pressure so i squeezed it and i heard the needle unseat. cranked it and it fired right up.

[tayto]

429bbf, you don't run the clip on the needle correct? I seem to remember reading one of your posts where you stated that...

[tayto]

Today I finished up the new hard line that goes from the fuel pump to the carb and replaced the rubber supply & return hoses from the pump to the frame. Put the carb back on and IT RUNS!! Looks like it was just the needle sticking to the seat. When I tore down the carb I installed the clip back on the needle and float arm and also went from a 70 to a 71 jet (Cliff recommended doing this because of the ethanol in the fuel these days). I was able to rough in the fast idle and regular idle, set the timing (was advanced 14* brought it down to factory spec @ 12*) and starting messing with the idle mixture screws but the underground parkade was getting smokey so we called it a day. I noticed with the initial idle setting (1700 rpm) I was getting nozzle drip, but once I got it dialed back to 500 rpm it went away, so hopefully the idle mixture screws will respond. I want to do a tune up on it as the owner hasn't done one since he bought the car 10 years ago. It also needs to get plates on it then we can do some real world testing and get it dialed in.

Thanks a lot for the help Cliff and blazer74!

[429bbf]

no i don't run the clip but i usually put 1 qt of atf in every fill up and i had not done that on the last couple of tankfuls it seems to keep my fuel more stable and last longer. fwiw

[Jeffs68]

no i don't run the clip but i usually put 1 qt of atf in every fill up and i had not done that on the last couple of tankfuls it seems to keep my fuel more stable and last longer. fwiw

Wow, never heard about adding ATF to the fuel, although I have heard it's a good intake valve cleaner.

[Hillbillyenginering]

I add atf to my gas on a number of vehicles.
But not  synthetic. Won't burn!

[429bbf]

one my diesels when i change the fuel filter i fill it with atf and start them up. they smoke a little but 200 plus thousand miles and no injectors or fuel pump work and they run like a champ.i think it keeps the carbon off the tips and helps lubricate the pop off valves. diesels for work gasers for play. fwiw