Really need some help here. I have a 89 YJ, 4.2L, MC 2100, all emissions are gone. I have adjusted the carb so when I initially start the Jeep, she idles at about 550 rpm. But when I push the brake pedal 2 - 3 times, my idle increases to 1000 Rpm. Can someone point me in the right direction?
Normal operation, Sorry, your Jeep is not broken, but dont get pulled over with all that emissions stuff missing, they CAN write you a fix-it ticket, no matter where you are in the USA.
Trying to learn something here. Is that because he has the MC 2100? My stock carb on my 89 4.2 5spd. doesn't do that. After a few seconds at a stop the rpm's go down to normal and also after letting out the clutch a bit. My initial thought was vacuum.
I am not certain if it matters or not, but I did not do the Nutter Bypass. I removed the old Carter carb, all emissions components and then mounted the MC2100 along with timing adjusted to 9 degrees brdc.
mine does it also but i can hear a vacuum leak when i do it so i know the diaphragm in my booster is leaking
A lot of teenagers are people who express a burning desire to be different be dressing exactly alike.
Panties aren't my favorite, but they're right next to it...
No one is normal, there are just a lot of weird people with things in common.
While your foot is on the brake, it takes a certain amount of vacuum to boost the pressure your foot is putting on the brake to keep it easier to hold the vehicle stopped.
basically the brake Vacuum booster is using vacuum from your engine to "Boost" your braking ability, the amount of vacuum being used causes a measured vacuum leak Causing your idle to raise, its a normal operation of vacuum brake booster systems.
Similar to a power Steering Hydroboost system that uses power steering hydrolic pressure to hold the brake, in vehicles like a Chevy Astro, or one ton truck, you push the brake and hear your Power Steering pump working....