Canuck Posted September 2, 2020 Share Posted September 2, 2020 I recently rebuilt the Qjet for my 1970 350with a kit and ever since then it is flooded every time I start it cold. Once I get it going it runs and drives fine. I can shut it off and restart it fine even when it is not warmed up. I’m speculating that I disturbed the two factory plugs on the bottom of the carb when I cleaned the parts and it is leaking all the fuel out overnight which explains why it is flooded every morning. Any other ideas? If it is those plugs what is the best way to seal them. I used JB Weld on the front carb plug that was leaking on my 72 Monte in the past and it worked fine. Anything else that may be better? Quote Link to comment Share on other sites More sharing options...
1970mcss Posted September 2, 2020 Share Posted September 2, 2020 I thought the auto parts store had seal kits for those plugs when I worked at a dealer. I don't see anything on line now. Maybe the jbweld is the way to go Quote Link to comment Share on other sites More sharing options...
wallaby Posted September 3, 2020 Share Posted September 3, 2020 So when you go out to start it for the first time of the day, you have to hold the throttle open to get it to start? Does it start ok when you do that, or does it start then die several times before it will keep running? Usually when those plugs leak it drains the float bowls and it takes several attempts, or long periods of cranking to get the fuel pump to refill them before the engine will run on its own. It's possible there is an issue with the choke adjustment, but with a Q-jet, those darn plugs are always a suspect. I heard rumor that there are replacement plugs that have O-rings, but I have never seen any. I have tried several types of epoxy to cure the problem, but its like impossible to get the area clean enough of lingering gasoline for the epoxy to adhere well enough to provide a leak proof seal. Then there is the continuous exposure to fuel...epoxy doesn't like it especially long term. Maybe Cliff Ruggles has a neat solution, I have not talked to him on the subject. Quote Link to comment Share on other sites More sharing options...
stangeba Posted September 3, 2020 Share Posted September 3, 2020 My 71 350 Qudrajet, after a week or more of not driving it, the carb is dry and I need to crank and crank and crank till the fuel bowl fills and then it starts. If I restart it the day after I drive it, it will start fine. My choke pull off is a bit rich but I just rev it up and it's good to go. An electric fuel pump would help but I like to stay stock. This has been normal procedure for decades when I start my Monte. My garage does smell of gasoline after each drive. Bruce Quote Link to comment Share on other sites More sharing options...
Canuck Posted September 3, 2020 Author Share Posted September 3, 2020 I do have a brand new choke pull off on there. Maybe I’ll put the old one back on to see if there is a difference. I have to put my foot in it to get it going and then it will run on its own without dying. Also remember the carb was rebuilt by an Accountant so who knows what else I messed up, LOL. I’ve built others with success before and really isn’t all that difficult. All the rods and linkage move freely as it should. Quote Link to comment Share on other sites More sharing options...
Canuck Posted September 3, 2020 Author Share Posted September 3, 2020 6 hours ago, stangeba said: My 71 350 Qudrajet, after a week or more of not driving it, the carb is dry and I need to crank and crank and crank till the fuel bowl fills and then it starts. If I restart it the day after I drive it, it will start fine. Bruce My 71 SS (the other Monte) is exactly like that if I leave it for a few days. The 70 is not like that though. Quote Link to comment Share on other sites More sharing options...
1970mcss Posted September 3, 2020 Share Posted September 3, 2020 Aaron, does the choke set when you put your foot to the floor? The choke pull off opens as the engine gets hot. I don't think the pull off would have anything to do with this problem. But I could be wrong. I have to set the choke and if the car has sat I have to crank it a bit. Also like Bruce my garage always smell like gas after a drive. Quote Link to comment Share on other sites More sharing options...
Canuck Posted September 3, 2020 Author Share Posted September 3, 2020 The choke sets properly. That does not appear to be the issue. If the choke pull off does not change anything with regard to fuel then I agree that it is likely not the issue. Quote Link to comment Share on other sites More sharing options...
1970mcss Posted September 3, 2020 Share Posted September 3, 2020 I'm sure that we have members that are smarter on carbs than I am. I hope someone else will have some advise Quote Link to comment Share on other sites More sharing options...
wallaby Posted September 4, 2020 Share Posted September 4, 2020 The choke thermostat is the coil thingy that mounts on the intake. It closes the choke when the engine gets cold, then releases its pull as the engine warms up. Meanwhile, you have the choke pull-off that operates on engine vacuum that is trying to open the choke as soon as the engine starts. It's a tug of war between the two until the engine gets warm, and the choke thermostat gives up the fight. From your description, the two items are working, (or close enough) at the time you are having trouble. You stated that the choke closes as soon as you touch the throttle. That's good. Next, you turn the key and it cranks but doesn't want to start. At this point, the choke pull-off isn't in play, so that isn't an issue yet. So it sounds like either you have too much or too little fuel to get the engine going. Mine does as Bruce described...empty float bowl takes a lot of cranking to refill, then it runs fine until it sits for days again. I smile and assume this is part of the design so I get oil pumped throughout the engine before actually starting. LOL Usually, the well plugs don't get disturbed when doing a rebuild, but sometimes they start to leak down all by themselves with no reason whatsoever. Maybe taking the carb off and filling the float bowls then setting the carb over a glass bowl will reveal if the plugs are leaking. I looked at the Cliffs' website, and the well plug issue is well spoken of. He pulls them out, taps the holes with a bottoming tap, or a tapered tap for the secondaries, then uses marine-tex as a sealant and uses threaded plugs to seal the holes forever. He calls it easy but it sounds difficult to me. I worry about the resultant shavings from threading going places I can never access again. Most of the people posting were those that tried different epoxy types, or JB weld with only temporary success. I see there are replacement WELL PLUGS (The technical name for the part) available, but you have to drill and use a puller to get the old ones out. Who knows if the new replacements will work any better. I might try spray painting that area to act as a sealant next time, as it's thin enough to seep into where it needs to go, and might set up even if some gasoline is in those hairline cracks where the leaks are happening. Epoxy, paint, plugs, having Cliff do it...hmmm..any method will probably take days to dry or set or perform. Those pesky plugs can be a real issue. Quote Link to comment Share on other sites More sharing options...
Tim972 Posted September 10, 2020 Share Posted September 10, 2020 I ran across this plug set doing some Q jet research. May be a better option than epoxy. Quote Link to comment Share on other sites More sharing options...
TommySS454 Posted September 15, 2020 Share Posted September 15, 2020 The well plugs are kind of an over blown problem. Not as many leak as people think. You can put a slight bend in a 1/8 rod and drive them out from the top and replace with the rubber o ringed set if you like. Then seal with j b weld. As far as the flooding issue, do you have the return line from the tank hooked up to the fuel pump? Should be 2 lines hooked to the pump. If one is plugged off the fuel in the line can become hot and expand. Forcing its way past the needle valve. Does it give out a puff off white smoke when it starts? Quote Link to comment Share on other sites More sharing options...
Canuck Posted January 18, 2021 Author Share Posted January 18, 2021 Update. I have been working on renovating the garage so the car was put aside for a while. Today I put the carb from the 71 on my 70. The 70 started and ran fine so I’ve narrowed it down to a carb issue. I pulled the top part of the carb off and discovered one of the 4 tubes had fallen off the top of the carb. I carefully tapped the tube back into place and should be good now. I checked the float level again which was right where it should be. After reassembly it is still running terrible like it is rich. All carb gaskets are new and vacuum lines are good. No vacuum leaks as far as I can tell. A friend of mine knows a q-jet guru that lives just a block over from me and will pass on my contact info. Hopefully he can advise. IMG_2506.MOV Quote Link to comment Share on other sites More sharing options...
1970mcss Posted January 18, 2021 Share Posted January 18, 2021 Are the idle screws adjusted properly? Quote Link to comment Share on other sites More sharing options...
Canuck Posted January 18, 2021 Author Share Posted January 18, 2021 I set them according to the instructions initially then made further adjustments after with no improvement. Quote Link to comment Share on other sites More sharing options...
Canuck Posted January 18, 2021 Author Share Posted January 18, 2021 I didn’t have to put my foot into it to get it started today. It seems like a mixture problem. When it is running the exhaust smells very rich. There’s a lot of black junk that comes out of the exhaust too as you can see in the photo I posted. Quote Link to comment Share on other sites More sharing options...
1970mcss Posted January 18, 2021 Share Posted January 18, 2021 My car was the same way when I bought it. I bought a rebuild kit and had a mechanic friend of mine rebuild the carb. He basically had the idle screws right on. I had the timing fine tuned by my shop and bingo. Good luck Quote Link to comment Share on other sites More sharing options...
zucchi Posted February 2, 2021 Share Posted February 2, 2021 On 9/2/2020 at 11:51 AM, 1970mcss said: I thought the auto parts store had seal kits for those plugs when I worked at a dealer. I don't see anything on line now. Maybe the jbweld is the way to go J-B weld is not a permanent fix for leaking well plugs. The proper solution are the replacement plugs as mentioned above and described by wallaby below… On 9/3/2020 at 2:10 AM, wallaby said: I heard rumor that there are replacement plugs that have O-rings, but I have never seen any. Those replacement 3/8" plugs can be found at: https://quadrajetparts.com/quadrajet-secondary-metering-well-plugs-ringed-plug-p-2944.html Quote Link to comment Share on other sites More sharing options...
Canuck Posted February 3, 2021 Author Share Posted February 3, 2021 I took the carb apart and checked everything over. After reassembly still did not run well. I opened the primary flap and it suddenly ran great. I put it in drive and still ran OK. I checked timing, set the fast idle and set the regular idle once it warmed up. I’ll have to wait and see what it does in the morning when I start it cold. It still seems to be running a little rich but at least it sounds good now. 2 Quote Link to comment Share on other sites More sharing options...
Canuck Posted February 4, 2021 Author Share Posted February 4, 2021 IMG_2581.MOV Quote Link to comment Share on other sites More sharing options...
sbarnette Posted February 6, 2021 Share Posted February 6, 2021 Sounds good. How did it do on cold start? Quote Link to comment Share on other sites More sharing options...
Canuck Posted February 6, 2021 Author Share Posted February 6, 2021 The cold start today wasn’t great but once I get it past the rough part it runs fine. I let it warm up and parked it. I’ll take some photos and video of what the carb is doing when I start it tomorrow. Quote Link to comment Share on other sites More sharing options...
Canuck Posted February 7, 2021 Author Share Posted February 7, 2021 IMG_2616.MOV Quote Link to comment Share on other sites More sharing options...
Canuck Posted February 7, 2021 Author Share Posted February 7, 2021 IMG_2617.MOV Quote Link to comment Share on other sites More sharing options...
Canuck Posted February 7, 2021 Author Share Posted February 7, 2021 The above two videos are of today’s cold start. Started terrible. Any comments welcome. Quote Link to comment Share on other sites More sharing options...
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