[Dodgeboy49]

I've taken a break from teaching this summer and have gone to work for a small plumbing business which has a 1982 Chevy S-10 for a spare truck. The 2.8L V6 was replaced about 20 years ago but has accumulated less than 30,000 miles during that time. It runs rough at idle and can be difficult to start when warm.

I serviced the truck yesterday and spent some time examining the carburetor and vacuum lines. The little Rochester carb is mounted sideways on this engine, and appears to be some sort of progressive two barrel design. At idle and all normal engine speeds, the front barrel appears to handle all the duties. The thing that caught my attention is that while the front choke seemed to function properly and open completely, the rear choke never moved at all. It's not seized, and all the linkage appears to be intact. I suppose that's fine if the carb normally functions as a one-barrel, but it just seems odd to me. I've worked on tons of older carbs and plenty of fuel-injection setups, but this little guy is kind of mysterious.

Can anyone tell me more about these carbs before I tear into it and screw it up royally?

 

[joat]

its a 2 barrel that runs on the primary venturi until internal vacuum gets high enough to open the other butterfly ( what you see as a choke ) ... it opens at higher speeds / loads .... revvving won't get it to open

the carb only needs 1 accelerator pump ( and choke ) for the first stage ...

look at the very back of the base ( firewall side ) of the carb for the PCV hose and valve ... both hose and valve are prone to cracking and letting air in ... hard to see , so remove the hose and valve to check them ....


BTW ... the 2.8 has a weak oil pump that barely supplies the engine with enough oil for cruising speeds at 60 MPH ... run it above that and you're asking to spin the bearings on the crank .... lots in the junk yards because of it ...

 

[Vonrow]

My brother had an old S-10 with the 2.8 and a weird carb too. When he rebuilt the engine he tossed the carb at me and said "do whatcha did with the one in your car." ( I drove a Pontiac 6000 with the 2.8 & the E2Se carb)
I ordered a carb rebuild kit for the earlier non-electric feedback E2 carbs (78-82/83??-ish) and tore out all of the electronics on the carb. That engine ran like a top when he put it back together. ...for a month... our 450+ year old white pine at the edge of the yard fell on it in a July storm. 'chevy on a stiiiiiiiick!' (and right after we put the new tranny in it too)

 

[Dodgeboy49]

Thanks for the tip on the oil pump- I'd bet that's what killed the original engine so early on. Thankfully, this isn't an electronic feedback carb- it should be at least possible to work on!

On the other hand, I did find out that Edelbrock makes a 4-barrel intake for this engine...

 

[joat]

Edelbrock makes a 4-barrel intake .. remember that weak oil pump ?

don't waste any money on this engine ... round town they'll last for years ... BUT a couple of good runs at highway speeds and you're playing Russian roulette .

 

[Dodgeboy49]

No.... this is just a parts runner for the most part. I couldn't believe that such an intake actually exists! I get the feeling that it would be kinda like putting a 2-barrel Weber on my lawn mower. It would look cool, and that would be about it!

 

[joat]

bit*h to start ... wouldn't idle below 1800 RPM ... a dog on power till you hit 60MPH ... then it would start to breathe properly as it winds out ...

yeah neat to look at ...just like adding some 18 wheeler tires / rear air spoiler / fuzzy dice / wheelie bars / rear parachute / hood with fake super charger / kid's seat and baby on board sign / etc ...

 

[Tractor-Holic]

I had plenty of "fun" with those 2SE "Vari-Jet" carbs on 250 sixes I had in my '81 G-10 van and a '79 C-10 pickup...they are basically a Quadra-Jet 4 bbl sawed in half,but they dont work as good as a Q-jet,that's for sure..

I got aggravated enough at the one on that pickup to do this to it..
I created my own carb adapter,and used a 600 CFM Edelbrock I had,and I ended up removing the linkage to the secondary barrels,as it did not like all 4 barrels opening,it was too much for the puny displacement..but it ran nice on the primary barrels alone ,it started up better,ran smoother,and got slightly better gas mileage than the original Rochester carb..