Car dying at idle, and anytime not under a load

[ian8950 2]

Hey guys, I'm having a small problem, I have a '69 fastback that is now dying at idle, and anytime I take my foot off the gas. The RPM's drop to about 500 for a second then it's done, though it will start right back up and run fine as long as I keep my foot down a little bit on the accelerator. I have checked all my vacuum lines and they all look fine. I also had an alarm installed on the car right before it started doing this though I can't see how that would possibly interfere with the idle. As for parts I'm running:

 

Edelbrock 500 electric choke carb

Elelbrock Performer intake and cam

Summitracing long tube headers through 2.5 inch pipes and flowmaster exhaust.

 

These are all less than a year old so I don't think it can be faulty parts. It was mentioned to me to spray the outside of the carb and the intake with brakeclean and if it runs better I have a vacuum leak but I've never heard of this approach before and wanted to make sure it isn't harmful. I know Jack and sh*t about timing and jack left town, but could this be a timing issue that just happened all of a sudden?

 

could this be something as simple as my idle screw came loose and I can just up the idle and it will work fine and not hurt anything?

[Brian Conway 264]

Could be a number of thing but first the easiest.  500 rpm's is to low for the idle setting.  Somewhere around 600-650 would be more like it.  Turn the idle adjustment screw slowly to get that idle up a bit.   Dirt spec in one of your fuel mixture adjustment screws ?  You could try a little timing adjustment to.  Before you do anything with the distributor make a few reference marks so you can locate the original setting. It is easy to do just loosen the distributor hold down bolt and with the motor running; turn slowly, gently, and with a firm hand clock wise 1/16".  If it, the idle, gets better give it another 1/16' and tighten down the bolt.  The other guys will be along with some more tips.  Brian  

[Pakrat 1,043]

My car has a Holley carb but I had similar issues when I first got it and believe it or not disconnecting the electric choke fixed it for me.

 

I also agree to try adjusting the timing as well, it is easy and doesn't take much, If your dizzy is a vacuum advance then be sure to pull off and plug the hose first, a golf tee works nicely. Mine is an Accel electronic advance so I don't have that issue.

 

The alarm could be just a coincidence but they also could have knocked something loose when connecting to the power source, check around the whole battery and solenoid area carefully to see if anything is loose.

[Hoover 12]

When was the last time you replaced your fuel filter? They're inexpensive, and should probably replaced at least once a year. You could also have bad gas in your tank. Good luck with your troubleshooting.

[nickjames138 15]

I had a similar problem. It only stopped running once the car was hot, but it wouldn't turn back on until it cooled down. Turned out my fuel pump in the rear couldn't handle the heat, so I installed a fuel pump under the hood. Fixed my problem.

[Dave R. 85]

Where are the newly installed alarm wires connected into the harness? Seems like the alarm install has something to do with your problem. Trace the alarm wiring. Or disconnect the alarm and see if the problem goes away.   Dave R.

[Print Dad 58]

Hello Ian8950,

Nice looking ride.

The first things I would do are

1. - Check all the alarm wires - -make certain something is not shorting out

2. - I will adjust the base idle up as suggested - then see what happens

3. - Check van lines

 

I wanted to also say a quick hi to Pakrat - -(sorry to highjack the thread)

Pak I just tried to PM you and you can't get PM's.

Jim from Medford Mass

 

Again Ian - -don't do too much as you might just make things worse.

Start simple 

[RPM 1,190]

Anytime I see that Pakrat has replied to a thread I check the dates. Original Post is a year old. Nice tip NickJames!