3.8 runs like crap.

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bad-s

n00b
Aug 25, 2008
2
0
0
i have an 82 malibu wagon with a 3.8. it has never ran too good and lately is worse. i dont need to worry about emissions so was considering a carb swap to seomthing that im more familiar with, so i could also lose alot of the emissions stuff and vacuum lines.

the car falls on its face and sometimes dies when you accelerate. if you ease the throttle, it drives fine but if you push the throttle any harder than a slight push it takes a second to catch up with itself.

its hard to describe symptoms on here but if anyone has any advice id appreciate it.

does any one ever do anything with these 3.8s? personally id like to just start from scratch with a new 2bbl and lose all the vacuum and electronics and just keep it simple.

what should i do.
 

Geesie

Master Mechanic
Feb 15, 2008
364
2
0
San Diego
IF YOU HAVE ELECTRONIC CARB:
Check your TPS. When you go WOT, the engine vacuum drops and engine vacuum is what pulls fuel through the venturis into the intake manifold. The TPS notices when you have WOT and pumps more fuel through to compensate for the loss of vacuum. If the TPS is bad, you lean out like crazy.

IF YOU DO NOT HAVE ELECTRONIC CARB:
Check the carb's power circuit. The primary side power circuit is operated by a vacuum piston in a cylinder connected to the intake manifold vacuum. When vacuum is high, the piston is pulled down. As vacuum drops, the piston is pushed up by a spring which allows more fuel to flow through the main jet.

FOR EITHER:
The accelerator pump is a spring-operated plunger connected to the throttle. When you mash the accelerator, it squirts extra fuel into the intake. The way you check this is to hold open your choke and look inside while you manually open the throttle as if you stepped on the gas. A small amount of gasoline should squirt across the intake.
 

megaladon6

Comic Book Super Hero
May 29, 2006
4,006
15
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Danbury, CT
in park or idle, snap the throttle open hard and then fully release so it snaps closed. if it bogs on opening, you need a tune up. you can also pull plugs to check color and condition. if you do a t/u don't forget the PCV valve.
 

bad-s

n00b
Aug 25, 2008
2
0
0
i was thinkin accelerator pump also but wasnt sure how to check on this car.

ill check out what you guys said. we just did a fresh tune up and having the same problems. the owner before did some funky sh*t with some of the vacuum lines and it really doesnt look right either. is there a place i can get a diagram? a chiltons should have it in there correct?
 

82malibu

n00b
Dec 28, 2008
4
0
0
I have an 82 sedan with the same engine. Went to www.garaunteedcarbs.com and bought a non computerized factory DualJet 210 from a 1979 Chevy truck with 305. Same problems as you were having, not anymore. Start tuning the carb from 1 full turn out. I started at 2 full turns out and it was way too rich. Personally, this engine doesn't perform too bad, but I'm just keeping mine running till after winter. Changing to 91 350. Hope this helps. Good Luck!
 
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