Join Date: Jun 2009
Location: Saipan (!)
Mad Max is online now
Re: Horrid idle
You can use carb cleaner and spray it around the carb base and general area. If the idle changes, you know you have a leak.
Does this rig have A/C? If yes, there is a vacuum reservoir located by the driver headlight in the engine compartment. They have a tendency to crack causing a vacuum leak.
The power brake booster (although rare) can also rupture the diaphragm causing a vacuum leak. Disconnect the hose and plug it. No change = no problem.
The EGR has been known to be a problem too. Reach under the mushroom and push up on the diaphragm. If there is no change = no problem.
If this rig has a pre heat grid under the carb (carb gasket) GET RID OF IT!
These go bad after multiple years of driving and don't help performance at all. You can buy a replacement carb gasket without the heat grid in it. You may notice a small gain in performance too.
Hoses: the crap quality hose GM uses for vacuum routing is also problematic. They tend to rot over time and split. Usually the split occurs at the connection to any point in the vacuum system.
And... the ultimate solution?
W E B E R.
Everyone on the forum that has done this upgrade has had nothing but good results to talk about.
1)'82 S10, 383, 700R4, Shorty
2) '85 S10, 3.4, 700R4 4x4 stretch cab (Redneck)
3) '90 S10 2.5, 5 speed shorty
4) '91 S10, Built 3.4, 5 speed shorty (Voodoo)
5) '92 S10, 2.5, 5 speed shorty, (Barbie)
6) '92 S10, 2.5 5 speed, Shorty
7) 1979 LUV, Buick 3.8 V6, TH 350 Shorty.