Impala Forums banner
1 - 3 of 3 Posts

Discussion Starter · #1 ·
Ok so my car was running really crappy, check engine light came on to tell me there was a vacuum leak. I replaced all vacuum lines and now it runs better, but the RPM's seem to move around erratically except at idle. I also checked to see if my EGR was working and it was. Whenever i drive it, it sort of "chugs" along as if its fuel deprived of something but i'm not sure. So does this sound like a fuel pump isse? The car has always had minimal use as its an 83 with only 49,000 miles and sat with almost no use for 8 years.
ok i've replaced the spark plugs, cap and rotor (which was much needed because everything was all melted and chewed up, O2 sensor, CTS, the car is running better but i am still experiencing the "chugging" i mentioned. Also, i must add that the car was sitting for 8 years with minimal use BUT until last summer i began to use it more and it was working fine all until 3 weeks ago. And i have ran the gas to 1/4 tank but that was a few months ago.
fuel filter and vacuum lines have also been replaced

Super Moderator
7,058 Posts
Also check to see that the carb bolts are tight. And that the choke is fully opening.

Another thing to check is the vacuum temp sensor switches. On my 77 I have two, both open/close at different tempatures. If these are not opening/closing at the proper temp then that will also cause the engine to chugg. If your car has the switches you will find them by the thermostat with two (or even three) vacuum lines to them. One will come from the carb and the other will go to some smog control item.

On my Impala one delays (opens the vacuum line at the proper temp) the EGR until a certain temp. And the other opens (actualy closes the vacuum line for) the right side exhaust restrictor (and closes the airsnorkel preheat - a custom mod of mine).

Your engine may have a electric temp sensor for the PCM to tell it when the engine is up to operating temp. Have it check as well. If one of them are bad the computer will give the car more fuel tring to warm up the engine that it thinks is still cold.
1 - 3 of 3 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.