1968 Charger Won't Accelerate- what gives?

[fozz71]

Took my '68 out today and she warmed up well in the garage first and I even rev'ved the motor up decently to get the juices going. Took it onto the road and no acceleration; I can get it up to about 20-25 and if I pedal it higher it just chokes, bucks and dies, just no acceleration at all. Has a 360 motor and 727 tranny- no knocking, smoke or pinging. Has a Holley dbl-pumper and intake manifold. Could it be either a fuel or valve issue?

Thanks,
Jim

[Cooter]

Was it warmed up?
How long had it sat? Fuel ok?

[cudaken]

First welcome to the site Jim!

First thing I would look at is if the Choke had opened. Next would be a clogged fuel filter.

If the Charger idles fine, I would say there is a 90% chances it is the choke.

Cuda Ken

[fozz71]

Ken,
 I had warmed it up about 10 minutes and took it up and down the 30 foot driveway (fresh gas too) to test the brakes before hitting the road. I had trouble with the choke when I first bought it, the thing wouldn't close at all so I loosened the 3 thermostatic coil adjustment screws and turned it so the choke would be closed for the start, then stuck the air cleaner back on.

Maybe that choke, the electric choke connection arm is broken and useless, won't work properly and causes me to have issues? Common with Holley 1850s?

Thanks guys,
Jim

[myk]

Take off the air cleaner lid and see, while the car is running...

[fozz71]

Thanks for the advice, will do and report back asap.

[fozz71]

Okay, here's the deal- my choke plate opens okay and is functional. I have a 360 engine with an 1850 Holley dbl-pumper carburetor, which may not be the best nor the easiest to get to run properly.

Does anyone have a recommendation of a better carb using the same Holley bolt pattern? Maybe a Carter or Rochester?

Thanks,
Jim

[cudaken]

 Jim, you say it is functional? Did you warm up the engine, see the choke open, try to drive it and had the same problem?

If you only check to see if it will open while the engine was cold, test it warm and take it for a drive. If it runs badly, wire open the choke and try again.

I am guessing you meant a 850 Holley and not a 1850 Holley. If the Charger ran fine before the carb sizes should not be a problem now. With out knowing what has been done to the 360 it would be hard to say if the carb is to big. My gut says a smaller carb would be better.

I like Holley and would look at a 600 or 650 CFM single pumper. But before you buy anything, more details pleases.

Cuda Ken

[fozz71]

Cuda Ken,
   You are correct, I was only looking at the choke while in garage. If this arctic spell releases us soon I'll take it out for a spin and see what is the deal. I just got my hands on a 2nd hand Edelbrock 600 cfm carb so I agree with you- a little less racing-type carb would be good for this size engine.

Thanks for your help and advice!  I'll be in touch soon with some results.
Jim

[cudaken]

Like I said before Jim, I am not a fan of Carter / Edelbrock carbs. Harder to work on, but many here do like them.

Go a head and start her up in the garage with the door open. Now if it is 20 degrees or lower, I understand.

Has the Charger ran fine before with the 850 Holley, or did you just add it and the problem just start? 

Cuda Ken

[Dino]

If you can find one in good shape or as a good core, consider the old thermoquad.  I recently replaced my Edelbrock performer 750 with an old truck t-quad and the difference is insane.  It took me a while to follow the step by step instructions on how to tune it but once set it's the best carb I can imagine.  Small primaries makes for a crisp throttle and good mpg (relatively speaking) and the large secondaries make for really good performance.

[fozz71]

Dino- can ya send me a pic of the thermoquad? My memory doesn't pull it up. Thanks! Or tell me what model exactly you are having good luck with?

[Dino]

There you go.  This is a 6545S from a mid 70's truck with a 440.  The carb is loosely assembled after cleaning so there's a few bits missing.  Google thermoquad and click on images to see tons of them.
It does not matter much which type you buy as long as it doesn't have all that smogger stuff so stay away from late 70's carbs.  Unless you want all that stuff. 

Thermoquad's are easily recognized by the black phenolic body and the angled fuel delivery in the casted horn.  And of course because they are spread bores.  The new Demon 1900 series carbs are based on the old TQ and one of the options is to have it with a phenolic resin bowl.  If my old TQ fails I will likely get one of those.   

http://www.summitracing.com/search/brand/demon-carburetion/product-line/demon-carburetion-street-demon-carburetors?autoview=SKU