Timing issue Solved! Now the motor surges.

[68coronetGLwannabe]

I have a  440 which is mostly stock. It has stock Mopar elect distributor, Mopar performance cam, Edelbrock performance 440 intake and a fresh 625 Edelbrock carb. We set the timing and don't have the vac advance hooked up. It seems to idle just fine but if you rev up the engine the timing will jump up about 20 degrees and stay there. If you just start it and let it idle its just fine. we replaced the spring in the distributor and it didn't help. This is with the vac advance unplugged. Any help would be great Thanks

[motorcitydak]

So you do not have a device operating to advance your timing and you are wondering why it will not advance?

[68coronetGLwannabe]

So you do not have a device operating to advance your timing and you are wondering why it will not advance?

The vac advance is not hooked, but if you just rev and release the engine quickly the timing will advance about 20* and just remain there until you shut it off.

[histoy]

It sounds like the centrifugal advance works, but then sticks in the advanced position until you turn off the engine.  You will probably have to disassemble the distributor, clean and lube it.

[68coronetGLwannabe]

It sounds like the centrifugal advance works, but then sticks in the advanced position until you turn off the engine.  You will probably have to disassemble the distributor, clean and lube it.

Thanks, we did that when we replaced the springs and it didnt help.

[skip68]

What cam did you put in it Wade ?   I just want to know...   

[68coronetGLwannabe]

What cam did you put in it Wade ?   I just want to know...   

I believe they call it The performance Hemi grind 6 pac cam.

[maxwellwedge]

What is your initial timing/RPM. Sounds like the thing is advancing very early, driving up your idle rpm.

[68coronetGLwannabe]

What is your initial timing/RPM. Sounds like the thing is advancing very early, driving up your idle rpm.

The initial timing was varied between 0 and 12 and still continued to have the same high idle problem. I replaced the distributor and I think I solved the not returning to idle problem. Now I notice the engine has a surging problem so tommorow I will check the manifold vaccum with a gauge and see if my metering spring are to heavy. I also notice if I screw the mixture screws all the way in it makes no difference in the way the car runs. So is it possible if the metering springs are to heavy the carb is not ever really running in the idle position thats why the mixture screws wont adjust? It also runs very (eye burning) rich. I hope this make sense.

[alcusswhen]

I have a  440 which is mostly stock. It has stock Mopar elect distributor, Mopar performance cam, eddy performance 440 intake and a fresh 625 eddy carb. We set the timing and don't have the vac advance hooked up. It seems to idle just fine but if you rev up the engine the timing will jump up about 20 degrees and stay there. If you just start it and let it idle its just fine. we replaced the spring in the distributor and it didn't help. This is with the vac advance unplugged. Any help would be great Thanks

Try replacing that eddy junk with Edelbrock then hook up the advance. It just may run good.

[68coronetGLwannabe]

I have A 440 which is mostly stock. It has stock Mopar elect distributor, Mopar performance cam, eddy performance 440 intake and a fresh 625 eddy carb. We set the timing and don't have the vac advance hooked up. It seems to idle just fine but if you rev up the engine the timing will jump up about 20 degrees and stay there. If you just start it and let it idle its just fine. we replaced the spring in the distributor and it didn't help. This is with the vac advance unplugged. Any help would be great Thanks

Try replacing that eddy junk with Edelbrock then hook up the advance. It just may run good.

When I put it was eddy carb and intake I meant it was Edelbrock I was just trying to abbreviate.

[68coronetGLwannabe]

Now the motor surges at idle and lower RPM. The manifold vac at idle is about 6 lbs. I put lighter metering springs in and it didnt help. I tried different timing settings but the surge wil not go away. I am starting to believe the 1406 Edelbrock is way to small for this 440. Any chance a 1407 750cfm would solve this issue and make the motor perform better?

[skip68]

Wade, I had the 750 eddy on mine and it ran like POOP!        The eddy carbs don't run well on low vac.   It sounds like your cam may be too much for an eddy.   I'm no expert but, I think eddy carbs are good for a stock engine.    

[skip68]

I did read that you can re-jet the eddy carbs and change the metering rods and it will help.   I did change the metering springs and it helped but it still was weak.   Even if the carb is small it should still run good and idle good.   It will just be lacking for it's potential. 

[maxwellwedge]

Now the motor surges at idle and lower RPM. The manifold vac at idle is about 6 lbs. I put lighter metering springs in and it didnt help. I tried different timing settings but the surge wil not go away. I am starting to believe the 1406 Edelbrock is way to small for this 440. Any chance a 1407 750cfm would solve this issue and make the motor perform better?

Check for vacuum leaks - 6" is really low for that cam.

[b5blue]

Are you thinking the cam is a six pack grind? That could be the resto Road Runner profile and you should get 14 inches of vac. easy.(six packs want good idle vac. to keep the outboards shut) You may need to work idle down a bit on the carb, then go back and turn dist. for high idle, idle down more on carb, then lean out A/F mix. Also take the dist cap off and be certain when you grab the rotor and force advance that it springs all the way back to no advance on it's own, if it won't you will never get it set right. Good Luck

[68coronetGLwannabe]

Are you thinking the cam is a six pack grind? That could be the resto Road Runner profile and you should get 14 inches of vac. easy.(six packs want good idle vac. to keep the outboards shut) You may need to work idle down a bit on the carb, then go back and turn dist. for high idle, idle down more on carb, then lean out A/F mix. Also take the dist cap off and be certain when you grab the rotor and force advance that it springs all the way back to no advance on it's own, if it won't you will never get it set right. Good Luck

That's the cam the guy that built the motor says it has. I just talked to him on the phone and he said the same thing about the vaccum, it should be at least 12. He is coming to look at it tommorrow. hopefully he can figure it all out and I can stop pulling what little hair I have left out. Thanks for all the help guys. 

[Musicman]

Edelbrock has a decent Tech Video section on their web site covering a host of common issues, this may be helpful to you. You seem to have a couple of issues going on here at the same time. Checking out these videos may get you pointed in the right direction anyway... If nothing else they may provide you with a better understanding of some of the more common issues that you read about all the time.

http://www.edelbrock.com/automotive_new/misc/tech_center/install/tech_vids.shtml

[elacruze]

Sounds like you have a couple interrelated problems.
Weak vacuum usually means you have not enough base timing, which if I read you right you never had higher than 12*; I have about 17* in mine. I don't know your cam and compression, so I'm only suggesting.

An engine with insufficient base timing will remain on 'high idle' if you cross the rpm point of the advance, preventing the return of the advance mechanism to base. As you increase the base timing to increase vacuum, you should notice the tendency to idle up improve. Total advance can be tailored after the base and curve are set.

If you get the base timing and vacuum up and you still have the high idle problem, you may have to install heavier advance springs to hold the base timing to a higher rpm.

Surging is more frequently a timing problem than a carburetor problem on naturally aspirated engines. Adjust your idle mixture after you get the vacuum maximized. More base timing will help with the rich mixture too.

[elacruze]

Sounds like you have a couple interrelated problems.
Weak vacuum usually means you have not enough base timing, which if I read you right you never had higher than 12*; I have about 17* in mine. I don't know your cam and compression, so I'm only suggesting.

An engine with insufficient base timing will remain on 'high idle' if you cross the rpm point of the advance, preventing the return of the advance mechanism to base. As you increase the base timing to increase vacuum, you should notice the tendency to idle up improve. Total advance can be tailored after the base and curve are set.

If you get the base timing and vacuum up and you still have the high idle problem, you may have to install heavier advance springs to hold the base timing to a higher rpm.

Surging is more frequently a timing problem than a carburetor problem on naturally aspirated engines. Adjust your idle mixture after you get the vacuum maximized. More base timing will help some with the rich mixture too.