340 6 pack help

Postby pink panther » 03 Mar 2005 18:28

Hello everyone. I'm a newbie to this forum and have had a chance to go through the message boards. You guys know your stuff that is for sure.

I have a question though,
I recently aquired a 73 challenger with a 340 6 pack setup, the intake is eldebrock with 3 2 barrel holleys. The car came from California and the fuel pressure guage under the hood reads about 6 1/2. Should it be richer or leaner now that the car is in Missouri? Also it tends to Idle around 1500 to 2000 rpm, but when the clutch is let out it idles around 1100 rpm. Is this normal? I'm not sure what else has been done to the motor but it was balanced and blue printed.

Any members around KC we have a club called HPAC, we have cruises and shows.

Thanks in advance for your help.

73challenger051.jpg
pink panther
 

Postby dave-r » 03 Mar 2005 18:35

Even with a hot cam there is no reason it cannot idle somewhere around 800-900rpm. It sounds like the carbs were never tuned right to start with so chances are it is too rich or too lean to start with anyway.

In fact I would put money on the engine not being on the idle circuits at all. It sounds like the throttle is adjusted open because the idle circuits do not give enough air at idle.

Read my posts about tuning carbs in this section.
User avatar
dave-r
Grumpy Old Man
 
Posts: 9842
Joined: 12 Oct 2003 21:45
Location: North of the Tyne, England

Postby pink panther » 03 Mar 2005 18:52

Thanks for the info, sounds like a good mechanic needs to look at this car as all the steps you indicated in carb tuning is probably beyond me. The car idles pretty good at start up, but after you drive it a little while it idles high with the clutch in. Unless you build the motor and set it up yourself it is hard to say what has been done to the car from the previous owner. I will get what you mentioned looked at and soundls like a good winter project letting a good mechanic go through the whole thing.
pink panther
 

Postby dave-r » 03 Mar 2005 19:08

I am not hot on manual transmissions but get the clutch looked at too. Most 'normal' mechanics don't know how to tune a carb for use with a hot cam. Make sure your guy knows what he is doing.
User avatar
dave-r
Grumpy Old Man
 
Posts: 9842
Joined: 12 Oct 2003 21:45
Location: North of the Tyne, England