318 Idle Issue
#1
New Member
Thread Starter
318 Idle Issue
Hey guys, This is my first post and i would really appreciate some help. Been at this for about a week or 2 now.
So i just rebuilt my holley 4bbl and installed pertronix. My timing is all tuned in perfectly and my idle/mixture screws are good.
Problem: After about 1min of idle, the car will drop to about 4-500 RPM then slowly die off (Even if warm)
Also If i gas it mild-hard then let go, the car will have trouble picking back up and it will drop to very low rpm again and die almost instantly.
Any help please? Thanks alot. -Jayce
Note, i have also sprayed around the intake with carb claener. No sign of any vacumm leaks anywhere
So i just rebuilt my holley 4bbl and installed pertronix. My timing is all tuned in perfectly and my idle/mixture screws are good.
Problem: After about 1min of idle, the car will drop to about 4-500 RPM then slowly die off (Even if warm)
Also If i gas it mild-hard then let go, the car will have trouble picking back up and it will drop to very low rpm again and die almost instantly.
Any help please? Thanks alot. -Jayce
Note, i have also sprayed around the intake with carb claener. No sign of any vacumm leaks anywhere
Last edited by JayceDUSTER; 09-11-2013 at 01:19 PM.
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JayceDUSTER (09-11-2013)
#3
New Member
Thread Starter
Automatic choke, i just did a little more tinkering and i felt some air coming out of the exhaust pipes right underneath the back seats, just before the muffler. Could an exhaust leak like that be causing it?
#5
Mopar Lover
J -
If there were air coming out before the muffler, you would HEAR it and wouldn't have to go looking to find or feel it. Or like TV said, you wouldn't be happy ...
Seriously a small exhaust leak can make you run lean, but usually not enough to cut the engine.
When the engine is dead cold, check the postion of the choke and check again after it's at full operating temp. If should be closed when cold and wide open when hot.
Other things to look at a lean fuel / air mixture and the coil. Some coils get cranky as they heat up and need replacing. Also make sure there are no wires arcing as the engine heats up.
Archer
If there were air coming out before the muffler, you would HEAR it and wouldn't have to go looking to find or feel it. Or like TV said, you wouldn't be happy ...
Seriously a small exhaust leak can make you run lean, but usually not enough to cut the engine.
When the engine is dead cold, check the postion of the choke and check again after it's at full operating temp. If should be closed when cold and wide open when hot.
Other things to look at a lean fuel / air mixture and the coil. Some coils get cranky as they heat up and need replacing. Also make sure there are no wires arcing as the engine heats up.
Archer
#9
New Member
Thread Starter
Archer, i will check the choke in the morning and look to replace my coil. Thanks.
moe7404 and TV, I was thinking it might need the thick intake gasket but i just matched up to the one it had on before. And the carb was dipped and the float levels are good
moe7404 and TV, I was thinking it might need the thick intake gasket but i just matched up to the one it had on before. And the carb was dipped and the float levels are good
#10
Could be EITHER rich and loading up, or lean
Where did you set timing? Have you done anything, even cursory, to check that the mechanical advance is working? Might be sticking
HOW did you set the idle and idle screws? You want to set the idle mixture so that the idle RPM or idle vacuum is peaked "off to the lean side" (CW on the screws)
Can you see or hear any fuel dripping into the throats? (high float level, bad floats/ needles, high pump pressure)
Where did you set timing? Have you done anything, even cursory, to check that the mechanical advance is working? Might be sticking
HOW did you set the idle and idle screws? You want to set the idle mixture so that the idle RPM or idle vacuum is peaked "off to the lean side" (CW on the screws)
Can you see or hear any fuel dripping into the throats? (high float level, bad floats/ needles, high pump pressure)
#11
Mopar Lover
I have a couple question.....
Why did you rebuild your Holley?
Was it running bad or doing this before you rebuilt the carb?
But since you already got the carb rebuilt and back on the car... And got the Pertornix installed.
Check the carb Float's level's...
Check The fuel pump pressure...
Check the fuel filter for being Plugged or restricted.
Check to make sure the choke is fully opening, when warm...
Turn the idle air screws out 3 turns from all the way in as a starting point.
Try setting up the Curb Idle a bit higher.... Maybe 1 turn clockwise...
If you get to the point of it idling...Set the timing to about 12* BTDC..
And let see how that's working for now.....
Why did you rebuild your Holley?
Was it running bad or doing this before you rebuilt the carb?
But since you already got the carb rebuilt and back on the car... And got the Pertornix installed.
Check the carb Float's level's...
Check The fuel pump pressure...
Check the fuel filter for being Plugged or restricted.
Check to make sure the choke is fully opening, when warm...
Turn the idle air screws out 3 turns from all the way in as a starting point.
Try setting up the Curb Idle a bit higher.... Maybe 1 turn clockwise...
If you get to the point of it idling...Set the timing to about 12* BTDC..
And let see how that's working for now.....
#12
New Member
Thread Starter
Could be EITHER rich and loading up, or lean
Where did you set timing? Have you done anything, even cursory, to check that the mechanical advance is working? Might be sticking
HOW did you set the idle and idle screws? You want to set the idle mixture so that the idle RPM or idle vacuum is peaked "off to the lean side" (CW on the screws)
Can you see or hear any fuel dripping into the throats? (high float level, bad floats/ needles, high pump pressure)
Where did you set timing? Have you done anything, even cursory, to check that the mechanical advance is working? Might be sticking
HOW did you set the idle and idle screws? You want to set the idle mixture so that the idle RPM or idle vacuum is peaked "off to the lean side" (CW on the screws)
Can you see or hear any fuel dripping into the throats? (high float level, bad floats/ needles, high pump pressure)
The idle screws are about 2 1/2 turns out. And i did actually see some fuel dripping down the throat the other day.. Fuel pressure is at about 7
#13
New Member
Thread Starter
I have a couple question.....
Why did you rebuild your Holley?
Was it running bad or doing this before you rebuilt the carb?
But since you already got the carb rebuilt and back on the car... And got the Pertornix installed.
Check the carb Float's level's...
Check The fuel pump pressure...
Check the fuel filter for being Plugged or restricted.
Check to make sure the choke is fully opening, when warm...
Turn the idle air screws out 3 turns from all the way in as a starting point.
Try setting up the Curb Idle a bit higher.... Maybe 1 turn clockwise...
If you get to the point of it idling...Set the timing to about 12* BTDC..
And let see how that's working for now.....
Why did you rebuild your Holley?
Was it running bad or doing this before you rebuilt the carb?
But since you already got the carb rebuilt and back on the car... And got the Pertornix installed.
Check the carb Float's level's...
Check The fuel pump pressure...
Check the fuel filter for being Plugged or restricted.
Check to make sure the choke is fully opening, when warm...
Turn the idle air screws out 3 turns from all the way in as a starting point.
Try setting up the Curb Idle a bit higher.... Maybe 1 turn clockwise...
If you get to the point of it idling...Set the timing to about 12* BTDC..
And let see how that's working for now.....
I cranked the mixture screws to about 3 out, and tightened up the idle screw. Timing is still at about 10*
The car is now sitting at 1k RPM, doesn't die out when i gas it (but gets close) and doesn't randomly die at idle
#17
New Member
Thread Starter
Drove it home, 2 hour drive and it ran great. The next morning, it wouldn't idle in gear. then it just wouldn't idle. Then i got a PCV valve for it, and it ran great again, Then the problems returned. Motors got about 80k on it, not sure if flipped over or not. I will run through it and check everything tomorrow
#23
New Member
Thread Starter
Well, the new vacuum advance is in... ALong with the regulator (which is set for 6psi). The PSi is at a steady 7 now. The fuel filter is not filling up with much fuel though...
Idle speed is fluctuating quite heavily from 8-1100 and when i gas it, it will stick at about 1400 RPM then slowly back down to 8-1100.. Timing is still set to about 10*, and i tuned the mixture screws down to 1 1/2 turn but the idle is still very high.
Again, i am stumped.. lol
Idle speed is fluctuating quite heavily from 8-1100 and when i gas it, it will stick at about 1400 RPM then slowly back down to 8-1100.. Timing is still set to about 10*, and i tuned the mixture screws down to 1 1/2 turn but the idle is still very high.
Again, i am stumped.. lol
#28
Try and borrow a carb to try.. I think you still have carb problem. I would take it apart again and at least blow it out with some cleaner.. Holley ? Check the metering blocks for warpage
#29
New Member
Thread Starter
Archer, just a hose straight from the dist to a port on the side of the carb.
TV, i was sorta leaning at that.this wouldn't be the first time a carb has fooled me into thinking it was in the clear, then when i replace it the car runs good as new...
TV, i was sorta leaning at that.this wouldn't be the first time a carb has fooled me into thinking it was in the clear, then when i replace it the car runs good as new...
#30
New Member
Thread Starter
Just an update- Got the new 4barrel on it and as it turned out 2 of the plug wires were swapped. (The #2 and #4). The car drove around the block perfectly, everything sounded in tune and seemed good. Going to push it a little harder today, but so far it looks like the carb was just bad