318 Idle issues

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Figure this is some good news for once.

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plumkrazee70 said:
Wow! Big difference. How does it idle now?
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Not the best when cold. I have to try to figure some things out with this carb, or try a new one.

When I first started working on this the choke thermostat was not hooked up inside the housing. I fixed that and just set the choke in the middle setting to start.

We also noticed the T slots were overly exposed from what I had read. I closed those down but when you set the fast idle screw it always opens those too much, and never lets the blades close back to where you had the T slots set. I have never set one up so I am not sure why that is happening.

When you first start the car it will idle at about 750 but just sort of chugs along and sounds like it wants to die but it doesn't. I think if I could get the choke and fast idle to work it would be much better. The car runs pretty good when warm. I drove it last weekend after the valve adjustments with no issues. I does stink rich when running though.

I think a carb kit and good cleaning would also be a good idea.

I am also considering buying a new carb for it and seeing if that fixes the issue also. Rusty has suggested the Brawler 650 D.P.
 
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Glad you’re chasing it down and making progress. I like the 670 holley street avenger. Has worked good for both my mild 318 and my 350
 
67Dart440GT said:
Not the best when cold. I have to try to figure some things out with this carb, or try a new one.

When I first started working on this the choke thermostat was not hooked up inside the housing. I fixed that and just set the choke in the middle setting to start.

We also noticed the T slots were overly exposed from what I had read. I closed those down but when you set the fast idle screw it always opens those too much, and never lets the blades close back to where you had the T slots set. I have never set one up so I am not sure why that is happening.

When you first start the car it will idle at about 750 but just sort of chugs along and sounds like it wants to die but it doesn't. I think if I could get the choke and fast idle to work it would be much better. The car runs pretty good when warm. I drove it last weekend after the valve adjustments with no issues. I does stink rich when running though.

I think a carb kit and good cleaning would also be a good idea.

I am also considering buying a new carb for it and seeing if that fixes the issue also. Rusty has suggested the Brawler 650 D.P.
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There is no carburetor that you can stick on out of the box and have it be perfect in all driving, starting, cold, hot, wot scenarios. None. Not one. I don’t care what anyone says. Before you buy another carb, (that you’ll have to tune anyway) spend a little time learning about the carb you have and how to make some basic adjustments/tune changes. They’re all fairly easy to tune and I’ll bet you can make a pretty large improvement on where it is now.
 
I run my choke wired open the car starts runs a little rough smoothes out as it warms up its summer time wire choke open let hit run then ajust.
 
Dartswinger70 said:
I run my choke wired open the car starts runs a little rough smoothes out as it warms up its summer time wire choke open let hit run then ajust.
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I adjust mine all the way open too. It's idling in literally 20 seconds.
 
TT5.9mag said:
There is no carburetor that you can stick on out of the box and have it be perfect in all driving, starting, cold, hot, wot scenarios. None. Not one. I don’t care what anyone says. Before you buy another carb, (that you’ll have to tune anyway) spend a little time learning about the carb you have and how to make some basic adjustments/tune changes. They’re all fairly easy to tune and I’ll bet you can make a pretty large improvement on where it is now.
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I agree.....and I FEEL like we've done that. Of course, not being there in person and only helping by phone and Fakebook, I don't know for sure. Colin's really sharp though. I tell him once how to do something and he's all over it.
 
RustyRatRod said:
I agree.....and I FEEL like we've done that. Of course, not being there in person and only helping by phone and Fakebook, I don't know for sure. Colin's really sharp though. I tell him once how to do something and he's all over it.
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There are definitely problem carburetors for sure. The edlebrock 750 is a know problem carb. The street avenger may be one of those, I’m not sure. But it’s worth (because he has it) putting a little time into actually tuning it (beyond jetting and needles) to see if it could work for him.
 
TT5.9mag said:
There are definitely problem carburetors for sure. The edlebrock 750 is a know problem carb. The street avenger may be one of those, I’m not sure. But it’s worth (because he has it) putting a little time into actually tuning it (beyond jetting and needles) to see if it could work for him.
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I ordered a rebuild kit for this last night. I am going to work on that this weekend. Hopefully that will help things out. It will be interesting to see what I find. I also ordered the Holley rebuilder book. Once I have this done and get it back running I plan on checking the crank case for vacuum.
 
TT5.9mag said:
There are definitely problem carburetors for sure. The edlebrock 750 is a know problem carb. The street avenger may be one of those, I’m not sure. But it’s worth (because he has it) putting a little time into actually tuning it (beyond jetting and needles) to see if it could work for him.
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Yeah how well I am finding out. Would you happen to know any fixes? If you do or have any ideas, send me a PM as to not get Colin's thread derailed. Thanks.
 
Valves tight eh, - stopped following, got too painful.
Very, very glad you found it,
post 33 , 62, 65
Good job .
 
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67Dart440GT said:
Not the best when cold. I have to try to figure some things out with this carb, or try a new one.

When I first started working on this the choke thermostat was not hooked up inside the housing. I fixed that and just set the choke in the middle setting to start.

We also noticed the T slots were overly exposed from what I had read. I closed those down but when you set the fast idle screw it always opens those too much, and never lets the blades close back to where you had the T slots set. I have never set one up so I am not sure why that is happening.
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If using the choke, the choke thermostat needs to be set stone cold, very first thing in morn, or similar. With the spring properly on the choke pin, rotate the cap till the valve just closes, secure it there for now.
It should choke properly and fall off fast idle with tap of gas pedal, some screw adj may be nec.
Choke should be full off warm, no choke interference.
If you can't get the t-slot right, and idle mixture screws have no authority, you may have to open the secondary a bit, there's a stop screw to be reached from underneath, on pass side, that should allow you to close the primary to get slots where they should be, mixture screws should work .
RRR prob covered all that, I missed a lot in between, sorry.
Good luck.
Cheers
Timing set 8*+ btc first .
Edit.
 
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It will get painful unless you are actually there looking at it... internet troubleshooting on a forum sucks guys want to tear the engine down first thing someone who doesn't know any better will find themselves in a bad expensive situation. Always start simple and cheap move in from there...when I worked in a shop or even side work ,teh worst jobs were when someone brought it in after throwing hundreds of dollars worth of parts at it or "I had it at Joe Bobs auto down town and he did blah bla blah..." you get it running hand them the bill and they ***** they "...already spent $800.00..." you have to listen to it and all you did was get it fixed for them.., Ill never figure people out...:)
 
Just remember the basics Spark, fuel, timing , internal engine damage/malfunction will keep an engine from not running, once it is running use your tools, timing light vacuum guage DVOM etc. and use a process of elimination. Take notes if you have to. Same applies to fuel injection its just that youd throw a code scanner in on your list of tools. Oh and teh tools are unlimited Im thinking about a broadband setup for tuning carbs I want to add that into my arsenal...
 
Dartswinger70 said:
Just remember the basics Spark, fuel, timing , internal engine damage/malfunction will keep an engine from not running, once it is running use your tools, timing light vacuum guage DVOM etc. and use a process of elimination. Take notes if you have to. Same applies to fuel injection its just that youd throw a code scanner in on your list of tools. Oh and teh tools are unlimited Im thinking about a broadband setup for tuning carbs I want to add that into my arsenal...
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Yes, the scanner is a must have tool for the 98' and up cars now. Even with the scanner it does tell you how to fix the problem, it will tell you what's not working correctly, so now you need to find out the reason. I go down the check list and check out all the possibilities, usually with an OHM meter, so not to buy something I don't need. Our old cars not charging, is not always a bad alternator, it could be a loose belt, regulator gone bad or even a bad wire. Trial and error!!!!
 
67Dart440GT said:
Hey everyone, I have been working on a little project for awhile now and have been running into some idle quality issues.

Here is what I have.

1970 318 with a 4 inch crank
Holley 670 Avenger Carb
Mopar distributor and electronic ignition
Edelbrock performer intake
Crane gold adjustable rockers
Comp XE268 cam

I pulled this engine this spring due to some seal leaks and just over all appearance issues. Noted in my "restoration" thread, I found many issues from the previous owner. After correcting all of them or most of them I am left with this idle issue.

Basically what happens is the engine shakes pretty badly when I first started it. I have corrected a lot of the shaking with timing (16 BTDC) and the idle mixture screws (2).

I have the idle set at about 700 RPM

I have worked with Rob @RustyRatRod on this for a few days and we have gotten it close but to me something still seams incorrect.

I let the engine warm up, set timing to 16 BTDC (seems to be it's happy spot)

Set the idle mixture screws with a vacuum gauge.... (slight adjustments initially make the engine really shake, then it settles down) These adjustments seem very sensitive and affect the shaking a lot.

Setting the mixture screws with a vacuum gauge really seems to have very little affect on the amount of vacuum produced. I am getting around 13-15 on the gauge and it bounces between the two.

Initially we thought this was some sort of vacuum leak so I checked all of the hoses, disconnected all of the vacuum lines from the carb and plugged them. This has no affect on the idle quality so I feel like I can eliminate those issues other than maybe the pcv?

I have taken the intake manifold off (edelbrock performer) and resealed it with new printo seals (previously had the metal stamped seals)

New carb to intake gasket.

I checked the bottom of the carb with a straight edge to make sure it wasn't warped.

I have sprayed water around the intake and carb, also brake cleaner with no noticeable vacuum leaks.

Motor mounts are tight and do not appear to be broken.

One thing I have noticed also is I can cover the primaries completely with my hand and the engine continues to run. I can close the choke almost fully with little to no affect on the engine running. Once fully close it does kill the engine.

I have uploaded a video to show the shaking.

Let me know if anyone has any ideas on what to look for.

Thanks!
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My personal best guess would be transfer slots in the carb. try turning the idle up a little on the carb then back the timing off. Base timing should be in the 10-15 degrees area, although every engine is different. not saying this is a sure fire fix, just something to try. if anything it won't hurt it and you can always put it back to where it is currently.
 
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