[zegto]

finally getting some time behind the wheel - BUT
the carb was supposedly rebuilt when engine pulled and resealed. when acc pedal is pressed i get an immediate stall then picks up. at steady speed, no or very little hesitation with accelorator, however, there is a sputter or miss. when i get on the throttle, no miss, pretty much clean acceleration. it's a bear starting when cold, even after i found and installed all the choke parts. new plugs, wires, cap, points, rotor.
wanted to bring it back to shop but lost confidence with 'choke not needed' and a bunch of other comments.
i know i have some reading to do, would like to get more familiar w/ the qjet, but any GENERAL thoughts apprciated, just to get me started. thx

[Coach]

What model, engine, and carb is on there?

-Harry

[zegto]

Sorry about that... Anyway, 70 gto conv., 400 ho, 4spd, original qjet carb.

thanks again in advance for everyone's advice. like having gtocentric tech in the living room - it has been very helpful getting this car back together after more than a decade.

[1967Tempest]

Is it a bear to start because of the carb or do you think that it is timing? Is it trying to start or is it just turning over, and over, and over, and over, and over, and over, and over, and over, and over,and over, and over, and over, and over,and over, and over, and over, and over,and over, and over, and over, and over,and over, and over, and over, and over,

Then starts. Then you have to keep your foot in it because there is not choke?

[zegto]

thinking it's more the carb. when warmed up it starts very easily. when cold, i have to pump it a bunch of times, then spin it for 10-20 seconds. after started and i push it a little i can hear some pinging. just doesn't pull like it used to. when motor was out, had new wiring harness installed, water pump, (just thinking of all the other stuff for me as well as you..!) timing set, ....batt cables... think that's it...

[zegto]

forgot the last part - once it get's going it will slow a little, think about stalling then flatten out and run. i did get the choke pieces and get them connected, however it looks like all the vac advances (pull off?) at the front of carb and dist are old, same w/ condensers.

[1967Tempest]

Well, if the vacuum lines are old and leaking, this can cause a myriad of issues from overheating to just poor performance.

Once the car is warmed up, what is the initial timing and total timing? Did you replace the timing chain with the crank and cam straight up? Meaning dot-to-dot?

Does it have a hard time staying running? Is the pinging detonation?

I have a Holley carb and in the dead of winter, 1 pump and she fires right up. She does not run well untill she gets up to temp, but I do not have to keep pumping and turning her over.

[wytnyt]

Originally Posted by zegto

think about stalling then flatten out and run

have you checked the accelerator pump to see if it squirts good?

[zegto]

no idea about the timing install - done by others
once running has no problem staying running
will look a little closer at the vac lines - thought theyd be replaced w/ work, but now questioning everything. will check out tomorrow eve, same w/ acc pump, activating from side should get a good squirt?

[zegto]

when given a pump, there's a 'spit' into the passenger side, not drivers
attached are a few pics - from the choke side before pump when cold, from drivers side after pump - does choke really close far enough?
also after reading some other threads re: plug wires etc. took a closer look at whats on there. 7mm belden wires? also a shot of what looks like a very old - original? delco remy coil.
again, thanks and all thoughts are welcome.

[1967Tempest]

Well the wires are ok. As long as each cylinder is firing. But only one squirt from the passenger side is an issue. There should be a shot on BOTH sides. The accelerator pump gives the engine a "shot" of gas when the throttle is depressed. This will allow the engine to stay powerful while the carb moves from the idle circuit to the main circuit.

So if this is not working correctly, there will be a BIG hiccup when you nail it.

[Leftyarmstrong]

There are some things we don't know about your car and what you have done to prepare for running. We'll start with the assumption that your fuel pump is pumping well. Should be a fair amount of pressure in the line if you were to remove it from the carb and it should pump well cranking. Has the car been sitting for a long time with the same gas in the tank? Is it chunky style? We've all been there... We get so excited to drive the car we just go, even though in the back of our mind we know better. I tell myself, "...it has a fuel filter." If the car's been sitting, you may want to remove the tank and clean out any junk in the bottom. Then, install a good fuel filter. What I've learned about them is that not all filters are created equal. Measured in microns, some filters only catch big chunks, while others filter down to say 8 microns. The filter that resides in the inlet of the qjet isn't enough IMO. That said, you may have gotten a good rebuild job on the carb and you may not. I've had a guy rebuild mine only to find out he did a lousy job. Took it to someone else and it made a big difference. Of course, no rebuild is going to help if there is junk in your gas tank being sucked into the carb which sounds like a real possibility from what you have described. Contamination can cause a number of things to happen inside a carburator, none of them good. I'm inclined to agree with you about the guy who said you don't need your choke. Even here in So Cal, my carb rebuilder showed me how to adjust the choke, the presupposition being that you need it to work right and let the air temp decide if it should be deployed. Try attaching a remote starter button on the end of a cable that you can hold in your hand whilst you are under the hood. When the engine is cold, with your free hand, hold the choke closed a bit and see if that helps it start and run better cold. (watch for fire breathing carburators!) Hope that helps. You're almost there!

[zegto]

finally got some time to get under there. pulled filter, looked clean, but point well taken. sounds like a thorough system cleaning is in order... however - could the 4 bolts mounting the carb to the man being FINGER TIGHT be an issue????? whatever confidence i had is now GONE.

[1967Tempest]

WHOA!!!!

That WILL cause a vacuum leak. Poor performance will follow.

[68gtoMN]

It's often the simple things. Tighten (do not over tighten - will warp carb parts) the attachment bolts, check vacuum lines, etc.....

Good luck!

[1967Tempest]

Are you close to me?? I can come over and help... I love digging into a PONCHO and troubleshooting...

[zegto]

Thanks 67 Tempest, but in the Boston area, looks like your in Jersey. This one's been pretty frustrating. As Lefty mentioned, I should probably have drained the fuel, cleaned out etc, but when i pulled the line and checked the filter this morning, no real evidence of residue or particulate found. When the car came back, the qjet was supposed to have been rebuilt, perhaps it was. Pretty clean, etc. When i checked the the other day it seemed like i was only getting a little spit into the pass side bore when activating the throttlle, this morning i got right up and in there and it seemed like both were giving a good squirt. was reading in the qjet manual that there could be other things beyond clogs that could do this, need to read up and get more familiar. very very very very frustrating. after all this time, finally get everything (almost!) put back together and to have this hesitation and then the intermittent stutter under steady throttle or even light acceleration is making me crazy. to the point where i'd hand it back over to a shop, but i want to know what's going on and would like to learn about the diagnosis/solution rather than simply throwing cash at it!!!! specially since it didnt work the first time!

[Cliff R]

The accellerator pumps that come in over the counter kits will not hold up to modern fuel. The NAPA 2-5514 kit for the early Pontiac carburetors still contains the early style pump with a black rubber seat on it. The life expectancy is about as long as it took me to type this.

Sounds like you have other carb issues in addition poor fuel delivery from the accellerator pump. Those carburetors have a pretty lean calibration on the primary side, which is compensated for by a primary POE or Pull Over Enrichment system. Unless the engine is stone stock and everything working perfectly, it will probably hesitate/surge some at light part throttle even if the carb build was done correctly with good parts.......Cliff

[74Grandville]

when it's cold, i would think that choke flap would close all the way.

[Leftyarmstrong]

Yeah, if its cold the choke should be closed. And when it's cold is when you want to tinker with that...In any event, do not despair, you are almost there...I got a bunch of help and referrals by joining local clubs: Pontiac and Chevy respectively for my two vehicles. Found a local guy who rebuilds carbs and he has helped me with several projects. Worth his weight in gold. See if someone has a backup carb you can throw on there and see how your engine runs. Then you can decide what to do about your existing one. Just keep tinkering. You learn something each time you go after it. Repeat after me: "It's a hobby. This if fun. I could be relaxing on the couch watching football, but nooo. I had to buy an old muscle car. Spend thousands of dollars and hundreds of hours...this is fun..."