If this were your car, what would you check??

[68Coupe289]

My engine has been frustrating me lately. First, the general specs:

289 (.060 over)
Edelbrock performer heads
CC XE 230/236 cam
Edelbrock Performer Intake (I know I need a better one)
Edelbrock 600 cfm carb w/electric choke on a 1" riser. I haven't changed a thing out of the box except the idle mix screws.
Petronix Distributer

Here's the deal. When I got this config put together last fall, it ran great. Then when it turned cold, the problems started, and continue even now that it's warm again.

When I start the car, it will not idle (the choke and fast idle work). I have to hold the gas a bit to keep the rpms at 1200 or so. It will run a little rough, with a few random misses.

Once it's warmed up to running temp, it pretty much runs fine, and will idle at about 900 rpm. It still seems to have a slight hiccup (miss) every now and then, but very seldom and random. Nothing drastic.

Here's what I've checked so far:
Plugs. (they were brand new in the fall) Pulled them in the spring. They looked black and fouled, so I replaced them. Improved the problem a bit. Also got new coil and wires.

Checked valvetrain lash. Everything is fine.

Checked for vacuum leaks. Found none.

Adjusted the choke and fast idle settings to no avail.

I want to check the timing, but my hub has no marks, and my motor doesn't seem to have a reference tab either. I can't see why that would be the problem, since it ran great for the first couple of months, and I have not taken it apart.

I think it may be running roo rich. I'm new to carbed motors, and don't know what possibilities exist.

Any ideas?

 

[slapper]

Any ideas?

Fuel filters?
dirt/water in the float bowl, or carb?

 

[allcarfan]

sounds like it just needs a tune up and maybe a carb adjustment. What you described is almost 'normal'. Check the points in your dist?

 

[sixtyfive]

may be colder here then where you live, and i hadnt drove mine all winter, dunno about you but that is basically my normal startup procedure for this weather about 50 degrees i dont have a choke cable though i have a rough cam, thats the way i like it .... maybee your cam just hada break in

 

[jcode68]

I had a similar problem with my 302 using similar components and wonder if you have the same problem I did. Turned out I used a resistor (white rectangular block) that came with either the Pertonix or the MSD coil (I think it came with the coil) per the instructions and diagrams. The result was a weaker spark which caused the card to idle like crap regardless of all the carb tuning I did. I was watching an episode of ShadeTree Mechanic (yeah, those goofs were actually good for something) on ignition systems and I revisited the whole setup I used. I ended up pulling the resistor and the car has run perfect ever since. Even if you don't have a resistor, you may be getting weak soark, so you may want to out a meter on it and check it out. Good luck!

 

[67GTA-FB429]

water in your fuel. did you keep the tank full all winter? If you did not, you can have water condense in your fuel tank and fuel lines....not to mention speeding up tank rust.

Also, there are small bits in the carb can get gummed up if not run on a regular basis.

 

[jikelly]

Check out the replies I left to other people who were having problems with their edelbrock carbs. Hopefully the info in the links will help.

http://forums.stangnet.com/showthread.php?t=433700&highlight=Edelbrock+carb

http://forums.stangnet.com/showthread.php?t=433703&highlight=edelbrock+carb

 

[mtiso]

pardon...
I am not to well wersed on car engines..
it seems however that if the new (used very little) spark plugs are fouled you have an incomplete burn of your air-fuel mix.

did you check the correct temp rating of the plugs (sometimes the simple things are over looked)
is the ignition working as it should (degree of the fire) did you check the fire angle dynamicly with a timing gun?

if those two above are correct, you get too much fuel. Maybe the accelerator pump on your carb is stuck? Or the choke does not close back up after you release the cable? Have you checked your carb visually?