What do you think ? Carb Questions

[76chevyC20]

I just bought a 76 C20, all original, 77,000 miles. Hasen't been driven too much lately until I got it. Truck runs awsome till I start excelerating ( such as entering highway speeds, or passing other vehicles. Then it starts to fall on it's face and coughs out black smoke. Slow exceleration is nice and smooth. Wondering if I need a carb rebuild or if I should other directions. Thanks.

 

[bucket]

Yeah, sounds like something's up with the carb.

 

[crazy4offroad]

What kind of carb? It's running too rich.

 

[76chevyC20]

I was thinking that would be a good starting place. I have an extra Q-Jet that I can do a complete rebuild on. Never done it before, but no time like the present to learn .

 

[Old77]

Could it be due to not being driven in a while and there being carbon built up causing the black smoke and stumbling?

 

[crazy4offroad]

If I had to guess, one of the linkage rods is bent wrong, one of the reasons I disliked the q-jet and went with Edelbrock. Much easier to tune.

 

[Irishman999]

Actually it kinda sounds like the vacuum operated pull off for the secondaries is shot. That will let the secondaries open premature and cause it to run rich.

If everything else is running fine check the vacuum pod. With the truck idling it should be holding the big flaps closed.

 

[Irishman999]

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[76chevyC20]

Thanks for all the info, gonna start checking into those items this weekend !!

 

[HotRodPC]

I think you're being steered in the right direction with this info 76.

Welcome to GMSB. We needed another OK member. I think you'd make about #9 of us now. What part of OK you from? We've got, Altus, Wagoner/Muskogee X 2, Mustang, Cement, and Moore X 2. Seems I am forgetting 1 or 2 too?!?!? How did you find out about GMSB? If you get a minute, visit the Introduction secton and start a thread on your intro. And be prepared. We like pics, so a build or construction thread would be cool too. Show some pics of the truck how you bought it, then some pics of the things you've done to improve it since you've had it.

 

[HotRodPC]

I was thinking that would be a good starting place. I have an extra Q-Jet that I can do a complete rebuild on. Never done it before, but no time like the present to learn .

That's a great attitude !!!

 

[89Suburban]

 

[Old77]

You're eatin' an awful lot of popcorn this morning 89Sub....need a drink???

 

[89Suburban]

You're eatin' an awful lot of popcorn this morning 89Sub....need a drink???

 

[HotRodPC]

NO kidding, I got tons of email from subscribed threads and over half of them is 89S eating fuggin popcorn, him and Dave and waving at something.