Idle problem

Its been a while since I've posted. Been workin on the rig. I put a new fuel pump on yesterday (standard mechanical replacement) and when I fired it up it ran great, but I've found that when I'm idling around a turn or at a stop sign/light, it is trying to die on me (has a couple of times too). It starts to chug and dies. Does this have to do with the new fuel pump, didn't do it before. Maybe the idle changed?
Anybody had this problem?

Thanks alot.

 

Easy enough to check the fuel pump. Run the outlet of the pump into a jelly jar, disable the ignition, and crank the engine. The jar should fill in 15 or 20 seconds.

If the fuel pump were starving the engine, you would expect it to be ok at idle, since not much fuel is needed then.

Why did you replace the old pump? Maybe that's not the problem... and it's still there.

 

The fuel pump went out. I got stranded on the side of the road. I had a mechanic friend take a look and he said the pump went bad. When it is running down the road, I am not having any problems getting gas to the engine, only when my foot is off the pedal and idling.

 

turn the idle screw up a little..Is the air cleaner and pcv valve put back on or are you just running it..

 

Nothing else is off of the engine. However, excuse my ignorance and newbie question but where do I find the idle screw, and which way to I turn it?
Thanks for puttin up with my ignorance.

 

Did you replace the fuel filter(s)? At a low idle, they might be so restricted, that the low RPMs can't pump enough juice through the crud.

Sorry for throwing out this "fishing" guess...

 

I'm having the same problem with my jeep. The thing idles just fine but while driving, once I put the clutch in and begin to coast, the engine dies. It's easy enough to restart with no gas fumes which makes me think it's a "lean" problem vs. a "rich" one or related to a vacuum leak. Any suggestions are much appreciated. I messed with the idle screw today but that didn't seem to fix it.

 

I replaced the fuel filter with the pump. So I don't think that could be it. HORNET: how did you adjust the idle screw? Also, if it is a lean/rich problem, what is a common fix for this?
THanks alot!

 

check your air filter. the idle will interactwith the throttle control somehow so when you turn the screw in(clockwise) the idle goes up. for the lean/rich mixture, you need to hook up a vaccum gauge to somewhere on the manifold that sucks vaccum. then you adjust the idle mixture screw until the vaccum is at its highest point, and finally bring it towards the rich side a quarter turn. Your engine will sound nice and smooth.

 

Uhmm... This may be an obvious question to everybody else, but is this on the 304? Also, do you have the stock intake and carb (Motorcraft 2100, I think)? I believe the idle adjust screw is tied into the throttle cable side of the carb, and turning it counter-clockwise should increase the idle RPM's. Don't hold me to this, as I don't have the stock set-up (PO made it 'better' with an Edelbrock system).
(Gentelmen, Am I even on the right page with this?)
Keep us posted... Cheers

 

Sorry for leavin out the details.
This is on a 304. It has been upgraded to a Edelbrock carb by the previous owner. I don't know the particular model. I am not sure about the intake. Sorry for the blurred details, but I'm definitely still learnin.

 

Can't tell you specifically about the Edelbrock, but it's the same carb as the old Carter AFB IIRC. You can get a book on Amazon.com that will tell you more about it than you'll want to know.

Typically the idle will have two adjustments - idle speed and idle mixture. To tune, you go back and forth between them to get "best lean idle" at the idle speed the factory calls for (say, 750 or 800 RPM). The mixture adjustment is at the base of the carb and the speed is on the linkage (typically). To increase the speed, you tighten the screw (clockwise) and vice versa.

Since you have a non-stock carb, you'll need to be a little resourceful (it's not covered in the TSM). Look at Summit or Jegs if they have the literature online that comes with the carb. CHeck if there's an Edelbrock web site that has tech articles. Stuff like that.

hth!