still having trouble

Unless theres another vacuum leak i don't know about, i think i've got that part settled. But when i start the engine the RPMs go to about 1000, then drop to 800. After about five minutes or so it'll go up 1000, and then fluctuate between 1200 and 1400 RPM erratically which i find odd. What could be the cause of this erratic idling I'm experiencing? Another thing i noticed is when you floor it while driving, it seems as if it wants to GO but it never really does. It almost seemed like the secondaries weren't fully opening. It also bogs still if you step on the gas slow. Although, i don't think i even know what it feels like when its actually running right since it never really was. Or, it could just be because its a 305, but i really don't know.

#1. The 305 with carb just doesn't have the power to allow the car to get out of its own way. It's a decent engine for driving around, it makes a great engine for store storming or whatnot - but it's not the engine for a 'power driver'. The fuel economy is nice, however.

#2, you could be having carburetor issues. I'd almost bet the farm on it. Rebuild time - 50k miles or not, it's now 25-26 years old. They NEVER last that long.

#1. The 305 with carb just doesn't have the power to allow the car to get out of its own way. It's a decent engine for driving around, it makes a great engine for store storming or whatnot - but it's not the engine for a 'power driver'. The fuel economy is nice, however.

#2, you could be having carburetor issues. I'd almost bet the farm on it. Rebuild time - 50k miles or not, it's now 25-26 years old. They NEVER last that long.

Do you think that a faulty EGR could cause this? Is an EGR something that would go wrong considering the cars age and how it was used? I already bought one but didn't want to install it unless i needed it.

Unless theres another vacuum leak i don't know about, i think i've got that part settled. But when i start the engine the RPMs go to about 1000, then drop to 800. After about five minutes or so it'll go up 1000, and then fluctuate between 1200 and 1400 RPM erratically which i find odd. What could be the cause of this erratic idling I'm experiencing? Another thing i noticed is when you floor it while driving, it seems as if it wants to GO but it never really does. It almost seemed like the secondaries weren't fully opening. It also bogs still if you step on the gas slow. Although, i don't think i even know what it feels like when its actually running right since it never really was. Or, it could just be because its a 305, but i really don't know.

with a vacuum gauge you will know if you still have a vacuum leak...there are ways to test for leaks using the vacuum gauge that takes the guessing out of the equation...


with your rpm/idle description you have a vacuum leak....replace all cracked and brittle vacuum lines and use gauge to measure vacuum....if you have a good engine the vac should be 21inches..and solid steady...if it is worn and engine needs some work it will fluctuate slightly and be around 19 inches..


if you have a leak you will get lower values...


in addition to the gauge you will need T fittings for testing and size adapters..

with a vacuum gauge you will know if you still have a vacuum leak...there are ways to test for leaks using the vacuum gauge that takes the guessing out of the equation...


with your rpm/idle description you have a vacuum leak....replace all cracked and brittle vacuum lines and use gauge to measure vacuum....if you have a good engine the vac should be 21inches..and solid steady...if it is worn and engine needs some work it will fluctuate slightly and be around 19 inches..


if you have a leak you will get lower values...


in addition to the gauge you will need T fittings for testing and size adapters..

Thanks for the help, i got 17 inches the last time i tested and i thought that was past what i should be getting? My Haynes manual said only 10 but i'll take your word for it "i heard the Haynes manual wasn't so good." By the way this engine should be almost like new with its mere 49,000 miles.

where did you buy your vaccum lines?

where did you buy your vaccum lines?

I bought em at Autozone. But thats not the problem anymore. Im almost positive its the carb right now and i'm bringing it to a mechanic i know tonight.

Thanks for the help, i got 17 inches the last time i tested and i thought that was past what i should be getting? My Haynes manual said only 10 but i'll take your word for it "i heard the Haynes manual wasn't so good." By the way this engine should be almost like new with its mere 49,000 miles.


go to the caprice forum and look up vacuum engine troubleshooting this will give you the correct vacuum info for your car...I put this in here to help owners like you troubleshoot carb engines... this is how it was done when repair techs where real mechanics...not scanner jocky's