Carb info/comments

[Bama647]

First off I know very little about carbs other than their basic functions. I started this because I wanted to lower the idle because sometimes (about half the time) the transmission hits hard in reverse and drive . I just got this truck so upon inspection I can tell the carb is probably not in the best condition. I believe the 4 barrel may not even be hooked up. I thought I may post some pics and someone might tell me what stands out to them and make suggestions. Thanks!

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

 

[Snoots]

VACUUM LEAK CITY!

Choke pull-off hose is gone
Vacuum source 'T' at the back of the manifold is missing a hose and 1 port is broken off
That cap on the top front of the carb is history
Port at the top center rear of the carb should have a hose that goes to (I think) the heat riser valve in the air cleaner housing
Gasket from the air horn on the carb to base of the air cleaner housing is toast
Forget the EGR

At first I thought what you had in your hand went to the base of the carb (but I'm not sure)

Get a piece of each (what's left of it) vacuum hose and go buy new stuff at a fitting length.
Tell us what size engine you have.

Holy cow! I can't tell what else is wrong from the pix, Cruise, vacuum advance; etc.

 

[78C10BigTen]

Not to mention egr aint hosed up

 

[Snoots]

Not to mention egr aint hosed up

If it ain't hosed up, it should be closed and not present a problem. Unless there is so much carbon on the pintle and seat that it won't completely close.

 

[1987 GMC Jimmy]

Yep. Does it have the vacuum diagram on it still? If so, follow it. If not, get the emissions diagram for a 49 state truck or van 305. If you have a TH350C, it’ll include the vacuum routing for the trans modulator. If a 700R4 or a manual, you don’t have to worry about that part. Be sure not to use the diagram for a full/mid size car or a Camaro because those are different.

 

[78C10BigTen]

If it ain't hosed up, it should be closed and not present a problem. Unless there is so much carbon on the pintle and seat that it won't completely close.

Get a block off and eliminate lol

 

[Charlie]

I would get a rebuild and replace ALL rubber lines.

 

[Bama647]

VACUUM LEAK CITY!

Choke pull-off hose is gone
Vacuum source 'T' at the back of the manifold is missing a hose and 1 port is broken off
That cap on the top front of the carb is history
Port at the top center rear of the carb should have a hose that goes to (I think) the heat riser valve in the air cleaner housing
Gasket from the air horn on the carb to base of the air cleaner housing is toast
Forget the EGR

At first I thought what you had in your hand went to the base of the carb (but I'm not sure)

Get a piece of each (what's left of it) vacuum hose and go buy new stuff at a fitting length.
Tell us what size engine you have.

Holy cow! I can't tell what else is wrong from the pix, Cruise, vacuum advance; etc.

The engine is a 305 in a 83 k10. And thanks for your help

 

[Snoots]

Let us know when you get all new 'rubbers'.

 

[ali_c20]

Rebuild the carb. It's worth the effort. Or buy a rebuild one, but a good quality product.
https://cliffshighperformance.com/

 

[TubeTruck]

That thing backfired more than once lol Yeah, rebuild it or get a new/rebuilt carb on there. From your last pic it looks like the body gasket blew out also.

 

[AZ-520]

Time to upgrade to Edelbrock, get an AFR gauge put in and jet it right. Quadrajets work good, but jet changes are a pain in ace.

 

[Paladin]

It's not a HOLLEY, get one! LOL

 

[Ewhitaker0020]

My vote is for an edelbrock 600 cfm carb! I have an 84 Chevy K10 with the wimpy 305 just like you, so basically the same truck. I upgraded to an edelbrock intake and carb and it made a world of difference. I also deleted all the smog crap that came on the engine and that took away so many vacuum lines. Now I only have about 3 vacuum lines I have to hook up. It's all so simple and clean under the hood now. I was just as confused as you are when it comes to carbs and vacuum lines. I'm still pretty new to them, but i've learned a lot thanks to the wonderful people on this forum. If you need any help just message me and I'll help all I can. Since we've basically got the same truck I can provide you with pictures of what I've done.

 

[Matt69olds]

Don’t create more headaches! Fix what you have. A Holley or edelbrock won’t fit the intake manifold without using an adapter plate, which adds one more potential leak area. And if you have a 700 trans, then you have to screw around with linkage/brackets to get the TV cable adjusted correctly. And if it’s not adjusted correctly, then you get to spend more money rebuilding the trans.


There is nothing wrong with a Q-Jet, once you understand how to tune and adjust them. The problem is very few people want to take the time to learn. Call Cliffs Q-Jet, have your carb number (stamped on the drivers rear). He can provide a quality rebuild kit, with the correct metering rods, jets, idle tubes, etc to calibrate the carb.

Cliff also has a excellent book on the Q-Jet, explaining production changes, rebuild procedure, testing, tuning, etc. well worth the money.