Yes, I realized that later last night. thanks! Or are you saying that it should not be slowly closing almost immediately after shutdown? I will time how long it takes to fully close. Even take time phased pictures.

 

That might be helpful. That carb sure does respond well though. Not the slightest hesitation. It's very cool.
Let me get everything else organized again and we will see. I have to get the poor starting issued solved first so I can concentrate on my other problem. I have to cross off possibilities as I go along so that I do not go around in circles.
I'm buying a starter, going to use a piston stop to make sure I know where TDC is, then reset the timing.
It is probably not a big problem. I just don't know enough.

I took out and labeled all the plugs. I will try to post good pictures. To me most are black and sooty and or sticky. Like they have been running rich I believe. I will put in new plugs too but I estimate these only have a few hundred miles on them.

I appreciate your help Lars

 

Starter broke because it is probably missing the brace that bolts to the back of the starter and to the engine block.

You've already gotten a recommendation for a starter. Remanufactured GM starter from Advanced Auto, O'Reillys, Pep Boys. 2000 and up Silveradoe, Suburbans, and Tahoes. $125 with lifetime warranty. As said, rare earth magnets, gear reduction, 20 lbs lighter.

 

If you go with the starter from Advance, buy it online for store pick up and use Promo code TRT30 to get 30% off.

 

I'm not sure I'm understanding... if the carb is responding well and running well, what is the problem with the carb...?

 

Nope, it isn't missing the brace.

 

Lars,
Most times when I go to start the car aftr it is running it will not start. But it is complicated by a general lack of ability to turn over as witnessed by the video.

Let me solve the cranking problem then I will get back to you.

Here is my plan:

Buying a new starter
I already checked that my TDC mark is truly TDC, (it is).
I have changed my plugs. They look bad, some sooty and I believe gummy.
I will make sure I have a good battery. and good wires/connections
Then I will start the car and set the timing.

After I have the weak cranking problem solved I will start over assessing if the car is hard starting.
I will let you know. Probably some time late next week.

 

OK, I bought a replacement starter and installed it. A little early to be 100% sure that things are fixed but here is what I learned.

The starter was binding causing an increase in power requirements.
The positive lead was tight on the battery but the wire was not tight on the battery terminal. The ground wire from the engine to the block was loose.
All these things were fixed. Now the car cranks fast. It starts up well and again too early to tell but I believe my supposed carb problems are gone. I will have to drive it a while to be sure.
I guess the very slow cranking rpm fooled me to think the car was flooding because it took forever to clear any error in throttle movement when starting. The car now starts all the time. I will post an update once I gain more trust in things.
Bottom line, is to solve your problems one at a time so you know where your at. Otherwise it is too complicated as there are too many variables.

Thanks and apologies to LARS. It doesn't seem to have been a carb issue at all.

 

Ok a year and a half later and I am responding again. Working on different issues off and on during this period. A couple of months ago I finally have the carb doing all it can do.
There were many issues that had me going in circles. Mostly because I didn't know what I was doing and became easily confused. Between starter, battery and carb problems I was frustrated. But the biggest issue was I had no idea what I was looking for. I had no idea what or how this car should perform.
Now I do!
I am embarrassed to say it but I figure It needs to come out because I wouldn't want anyone to go through this as long as I did!!

My accelerator pedal was not moving the carb arm full motion. As in about 2 inches short of full travel! The secondaries were never opening!

I fixed all that and now the car is fantastic! I have huge bucks in this engine and I was grumbling and griping thinking that this is the best 68 technology can give me. I had no reference point. Driving without secondaries. Disgusting!
When I worked through my engine build here on the forum, years ago, I was pretty assured I was going to have a fun street machine. But everyone's perspective of that is different. I never trusted myself.

So all is good now. The car frightened me for a couple days till I got used to it!

383, camel hump heads, Muncie close ratio, 3.70 rear pumpkin, headers, cam for low end torque for street play.

So I had about a month of terrorizing the neighborhood like a dumb kid.
All is good. (except for the snow and -15 coming tonight) Can't wait till March or April!

So Lars was correct on all points with only one exception, that being the carb was messed with. It NEVER was after his initial rebuild, or since. But regardless I appreciate all his extended efforts. Thanks LARS and all contributors.

I need to get some detailed pictures of my beautiful car and info on the build posted over the winter.

 

Well congratulations and sharing your experience here will be a huge benefit to those trying the same improvements. I guess its the passion for performance that drives us all here just by owning a corvette. But there is always new and unique problems which can become overwhelming. I guess we all have to start somewhere and time can be a consideration to as we only live once and most everyone has more than just a corvette on their bucket list. My favorite advice is to spend more time learning to tune the car mastering the carb and timing curves before taking the engine apart to prevent surprises when the motor is reassembled. Well i do hope you hang around enough to prevent someone dream build from becoming a horror story.


Thx for posting all that experience. And congrats on getting your dream build going like you wanted.

 

Hi Lars,

Sorry to dig up this thread but I have been searching all over about the QuadraJet's choke pulloff its spring where a divorced choke is used. I have a 1972 C10 with a 350 / TH350. The previous owner installed a Quadrajet 17058213 (78 GMC Truck) that he got from a auto parts store (replacement). I believe I should have a 7042208, which I have sourced and is out for rebuild but won't be ready until May 2021 (if I am lucky). Again, I do have a divorced choke.

The Quadrajet 17058213 is running good and cold starting I haven't any problems, the Choke closes and fast idles just fine. When we had our Texas Winter Storm (dropped to 7 degrees here) she started like a charm!

My problem is after reaching operating temperature, say after driving around 10 miles or so, then I shut off, I have a hard start after roughly 5min ~ hour later. I turn her over for ~5 seconds and she doesn't run. I stop, give her a bit of gas by lightly touching the peddle and turn her over. She starts then and perhaps she struggles a little for a few moments. Though often I just rev up to about 1k or so for a few seconds to get past the struggling.

So my question is about the Warm Choke Position at Shut Off / Start up during this 5min ~ hour period. What is the Choke plate suppose to do during this warm time shut down? In my case when I shut off, the Choke mostly closes and the best that I can tell is that spring is keeping down pressure on the divorced choke, thus closing the choke plate a bit. Soon as has the engine starts up the choke pulloff gets its vacuum and the choke plate snaps fully opened.

I don't think the choke plate being part/mostly closed is the full issue with my warm starting but I am thinking the air being restricted is not helping matters. That is assuming what I am seeing with the choke plate after proper warm up / shut down is even a issue. If that is improper operation, how do I adjust that out and I guess not effect what is working (cold starting choke properly closed by the divorced choke).

 

Being a new member you probably don't know it's not a good idea to resurface old threads... always better to start a new one

 

Hi, I do know it is generally bad etiquette (which is why I started off saying sorry) but I never actually ran into a form rule not to do it. So I do now apologize for breaking a rule - however Lars's post that I quoted was really spot on what I been looking for and I am "hoping" he is still subscribed to this thread. I thought about PM'ing him but that seemed to be rude and I am hoping my question that is expanding on the Choke might help others.

Again, apologizes for breaking a forum rule, thank you for taking the time to point that out - perhaps you can blame it on me being a Chevy Truck owner and not a vett

Richard