318 Wont idle

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Rebel1977

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I know there are many threads about this, and i feel like i have read them all and tried everything. So bear with me, and i apologize for yet another "my small block wont idle" thread.

So here is what i have and what i have done.

318 with electronic ignition, 3/4 cam, 360 heads, weiand intake, edelbrock 650. I drove the car about 10 years ago and it ran great, started great, idled great. Then it sat at my brothers shop for ~10 years. I got the car back, pulled the tank, cleaned it, new sending unit, blew out the lines, rebuilt the carb, changed the plugs, wires, distributor cap and rotor. She starts right up, runs at fast idle, but will not idle normal, will not idle in gear, and when i manage to get it moving she is way down on power. Since getting it started, i have pulled the carb back apart and rechecked the idle circuits and they seem clear to me, i have swapped two different ECU's into it, one of them being brand new, i have verified that i dont have any vacuum leaks, including using the ether test around carb base and intake to head gasket, i have put a new coil in, i have checked the gap inside the distributor, and i have checked that there is not any play in the timing chain. The timing was never messed with and the motor only has about 20k miles on it, as i built it in high school and know the mileage on both vehicles it has been in.

The only thing i can think is maybe there is something haywire with the distributor itself? but i have never messed with the distributors all that much, they have always worked when i put them in.

I dont think i have missed anything in regards to what i have done with the car, this is a 5 month long frustration and i am at a loss right now. Any help is extremely appreciated. Thanks.
 
I havnt, the reason being that i know it hasn't been touched since it was last driven, and the funky setup that the power steering pump has, i have to remove the pump to see the timing marks....
 
Up front i'll tell you i'm no dizzy or electronic ign expert. There are guys here that know there stuff and hopefully the'll see this thread.

My first thought is a voltage issue. Meaning at low rpm's it's just not there. Maybe the alternator or voltage regulator? Congrats on covering just about all the bases. That's really the only thing that comes to my mind right now.
 
If it has an EGR valve, make sure it's not stuck open. That would cause a huge internal vacuum leak.
 
When i adjust the idle screw down it just chokes out and dies. It does not have an EGR valve.

I am in the midst of trying to check the timing, but its been a while (about 8 years) since i have checked or changed the timing on anything. So i am researching that and i will let you know how that goes.
 
Does it run smooth at a high idle? Or is it posible you have a stuck valve and maybe then it bent some pushrods? May be not hitting on all 8 cyl.
 
It runs smooth at high idle.

I just checked the timing, and it is set at 35 degrees total advance. Still does the same, when adjusting the idle screw down to bring the motor down to idle, it chokes out and dies, but give it just a touch of throttle and it revs up nicely.

One thing i noticed, and not sure if i remember wrong, but when i was checking the timing it dosnt stay put every hit, but jumps back and forth by several degrees.

When checking the timing, i checked it with the vacuum advance unplugged and capped, then set the rpms to 2500, turned the dial on my timing light to 35, and i didnt have to move the distributor hardly at all and it was at the 0 mark, though it would jump several degrees back and forth but always come back to 0. hope that makes sense.

At a loss, dont know what else to try.
 
Ah, the total timing monster....

What's it got at idle, that's at least as important as the total number.
 
I couldn't find the timing at idle, especially since it runs for about 2 seconds at idle then dies.

Any suggestions on how i could do that? Like i said, its been a very long time since i have messed with timing.
 
Two clue finders for you.

1.hit it with a shot of your starting fluid when it tries to die out and see if it tries to keep running. (don't open the throttle at all) just as it starts to die out , hit with fluid.
What does it do?

2. Leave your timing light connected and when it starts to die out see if the timing light stops flashing as it slows down and dies.
 
If its timing, mark where the distributor is now so your can put it back, then loosen it so you can move it then move it until it idles then check the timing.
 
Squirting just a mist of starting fluid at it when its about to die brings it back to life.

The timing light flashes, albeit erratically, right up until the engine dies.

If my slow brain is putting together what your getting at, i need to take another look at the carb....yes?....
 
is it getting gas?
the accelerator pump rotten?
vacuum leak?
bad fuel pump?
dirty fuel filter?
bad gas?
nasty carburetor?

sounds like a carb/fuel problem or massive vacuum leak
 
73AbodEE said:
is it getting gas?
the accelerator pump rotten?
vacuum leak?
bad fuel pump?
dirty fuel filter?
bad gas?
nasty carburetor?

sounds like a carb/fuel problem or massive vacuum leak
Click to expand...

Gets plenty of gas, Fuel filter is full and stays that way
Accelerator pump is new and works well
Checked every where and havnt found a vacuum leak
Fuel filter is new
Gas is new (tank was cleaned out)
Carb has been rebuilt...but it was rebuilt by me, who is to say the least rusty at it. so i may have messed something up.

So back to messing with the carb.
 
x2 fuel pump might not getting enough pressure at idle
 
Voltage,and fuel pressure check time. With a mechanical fuel pump,buy one swap it. Electronic parts,don't usually go bad,sitting. Swap the pump,light it. Take a voltmeter, look for mid 13's,to upper 14's. Is that a fresh battery,or the old one,with a jump charge?.Start there...
 
Figures. I post,all the info comes in(lol). Can you borrow,a known good Carb? Rebuilds,don't always fix carbs. Short ,of a full agitation soak,the main well still could have deposits in it.
 
one sure fire way of weeding out the carb is to just put a good known running carb on it. every car enthusiast should have one handy lol
 
I did get the check balls and needles back in correctly, float levels were set correctly.

Battery is new, and i have checked the voltage at the battery and at the coil, and at the ballast resistor, and all voltages check like there supposed too.

The fuel pump is older then the motor itself as it was a high flow pump that came off my brothers 318 that he had been driving for several years. Didnt think that would be it since there is always gas in the fuel filter, which i have past the pump just before the carb.
 
Sounds like your problem is in the carb. If you can borrow a good one than that will take the mystery out of your problem. One thing for sure I think you have narrowed it down to a fuel or vaccum leak problem.
 
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