Help - My 68 Charger Mysteriously Died

[Evoking]

I've got about 500 miles on my 68 with new 505 stroker. It has a Quickfuel 850 carb and electric fuel pump. It would run perfectly smooth some times. Then other times it would bog then GO pr bog and stall when I try to accelerate from a long light.  I think the key was long light or idling but not sure. I guess this is what some call "build up"?  I'm very new to carbureted cars.

Well yesterday I got stuck in full blown stop and go traffic. Temp was fine as it was cool out.  While merging onto a highway in slow traffic it stalled and would not start. I looked at the carb and it didn't look like I saw fuel in the little floater window but wondered if this was because it was flooded and too full. Fuel pressure gauge looks good when I turn the key to on.  Yet I did notice that when I press gas no fuel squirts into carb.

How can there be fuel pressure but nothing going into carb?  Also any good shops you guys recommend in SoCal?  Just moved to Irvine. 

[70 sublime]

Vapour lock ??

[Paul G]

Sounds like a fuel delivery issue. Could be vapor lock, but you say it was cool out? Are your fuel lines routed near the exhaust? Which electric pump are you running? The inexpensive Holley blue pump is notorious for failing as you describe. I have removed two of those on different cars and put them in the trash.  What is the fuel pressure at idle? Should be about 6 PSI.

You could try this; disable the fuel pump by pulling out the fuse, or disconnecting the relay. Run the engine till you see the fuel level drop well below the sight glass in the fuel bowl. Turn off the engine, re-enable the fuel pump, re-start the car and see that fuel pressure is still 6 psi as the bowl fills.

[c00nhunterjoe]

If the bowls are empty and no fuel is coming out of the squirters, yet your gauge says you have good pressure, then you need to verify that you actually have fuel coming through the regulator when it dies.

[Evoking]

Thanks for the insight. Went to start it today and it cranked up like normal.  Need to get to the bottom of this as I can't be stalling when cruising with wife and 2 babies!

[Evoking]

Sounds like a fuel delivery issue. Could be vapor lock, but you say it was cool out? Are your fuel lines routed near the exhaust? Which electric pump are you running? The inexpensive Holley blue pump is notorious for failing as you describe. I have removed two of those on different cars and put them in the trash.  What is the fuel pressure at idle? Should be about 6 PSI.

You could try this; disable the fuel pump by pulling out the fuse, or disconnecting the relay. Run the engine till you see the fuel level drop well below the sight glass in the fuel bowl. Turn off the engine, re-enable the fuel pump, re-start the car and see that fuel pressure is still 6 psi as the bowl fills.

I raised the idle a tad today to reduce likelihood of stalling.  It still bogs at times when I first tip in throttle - so I then have to either quickly give more gas which creates over-response or I have to slam into neutral to keep alive.  Finally, it would sometimes let out a loud pop backfire a if I give lots of throttle while in drive to keep it alive.

So here is my question.  Is it true this 850 carb is categorically "too much" carb and might be causing the problem?  Or is this likely simply air-to-fuel tuning that every carb initially needs?

[Paul G]

The 850 is not to  large for a 500" motor. That is the carb I will be using on my 500" stroker. Has the carb been gone over and the basics set? Floats first, then adjust idle mixture and idle speed, then make sure the accelerator pump is adjusted correctly.

[c00nhunterjoe]

The bog and pop you describe sounds like a classic lean tip in. Go up in squirter size. But your stalling with no fuel in the bowls needs to he addressed 1st.

[Evoking]

The bog and pop you describe sounds like a classic lean tip in. Go up in squirter size. But your stalling with no fuel in the bowls needs to he addressed 1st.

Thanks for this. What exactly do you mean by go up in this quarter size? By the way I do plan on taking it to a shop this week for comprehensive tune.

[69wannabe]

Like Joe say's, sounds like it's lean. I had to jet my 850 up on my 493 to get it tuned in. It had a lean stumble off idle and I had to go up on the pump squirters too. My carb is a holley double pumper and should be about the same as your carb.

[c00nhunterjoe]

https://www.summitracing.com/parts/hly-121-35?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-holley&gclid=Cj0KCQjw3ebdBRC1ARIsAD8U0V5CqpzNGOafnopqoWlk5jtmLS3tH0wCgGx1RsmjfHGeKycHIiQkHDQaAquoEALw_wcB

These guys. Will have to look at yours and see what number is in it. Probably 31s stock. Whatever it is, go up 2 sizes based on the description you have given. But again, fix the lack of fuel 1st.

[Evoking]

Had it dyno tuned. Runs perfect now ;-)

[c00nhunterjoe]

What did they do to fix the lack of fuel/carb empty?

[69wannabe]

Curious also to see what they did to make it run good. I think I wound up with #35 squirters in mine but I can't remember what jets I wound up with since I haven't had my carb apart in a long time. I think I went up two or three sizes front and two sizes on the back but like I said it's been awhile since I have seen the inside of it..

[c00nhunterjoe]

I had 40s in my 383. Every build is different.

[69wannabe]

Yep, the 750 DP I had on the stock stroked 440 had 28 squirters front and back in it and it worked fine. Like you say, every build is different....