440 engine running issues - Sputter at high RPM

[stappy]

Ok, so I have searched for a solution to my problem but I am sure I am just not diagnosing far enough.
I have a 1977 440 Motorhome engine in a 1969 Charger. I transplanted the whole thing electronic ignition and all. I have replaced the ignition control module (Oem style), coil (Accel yellow coil), all plug wires, new cap and rotor, new voltage control module (twice), Newer alternator, New fuel pump, New fuel tank, line, and sender, and new spark plugs.

Other notable points, I tried to rebuild the ThermoQuad and wound up making it sooo rich that eyes watered and could not breathe. I tried another Holley and same result. Tried a third and have been tinkering with that one now. I am not sure of High end jetting but idle and power valve should be good as well as all passages cleaned out. I have purchased an Air Fuel Gauge and I had O2 sensor bungs installed in the 2.5" duals that come off headers on the engine. I do not have that installed yet.

Here is the issue: At idle and low mid-range it seems to run great. At upper mid-range and beyond it develops a misfire that to me sounds like ignition. The car keeps accelerating though.

I had the distributor out and the weights were all frozen which I fixed with some penetrant and moving them back and forth. I also saw the vacuum advance plate was bent so I flattened that out and to me it looked like the vacuum advance arm was connected to the wrong place. There were two locations it looks like it could have been connected to so I put it in the other one. I did check timing and the mechanical advance is working as it should now and vacuum pulls it on further indicating that is also working.

What should I check next? What information should I be chasing down to determine the cause of the sputtering.
https://goo.gl/photos/8BuRhWS1JfGFJxu1A

p.s. I did put in new voltage regulator and the reading at the battery is around 13.7. It starts and always seems fully charged and headlights are bright at night. I have not chased it down as 13.7 is better than the 0 volts I battled for weeks only to find out a bad new voltage regulator.

 

[moes]

did you check the reluctor air gap in the distributor. Use brass feeler gauges to check for a .008

 

[PurpleBeeper]

Hmmm.... when you say "high rpm", what rpm are you talking about? Off the top of my head, I'd want to consider the timing (you said you've had some ignition issues) and valve float, which I would "guess" you'd be getting at 5000-5500 rpm or so with stock valve springs.

On the timing, what is your initial timing? Full advance timing (with only initial + mechanical advance & vacuum advance un-hooked)? How much vacuum advance are you getting?

Also, it may be a long shot but has happened to me.....maybe you've got a plug wire that's not fully on the spark plug and/or burnt and/or has the terminal half way pulled out on the plug side?

Another thing might be "something" in your carburetor......maybe running lean at higher rpm? Or a vacuum leak somewhere? (though I'd expect to see that show up more at low rpm) One plug fouled?

 

[stappy]

Mid throttle. Would not be valve float at the RPMs this sputter happens at.
I have double checked the spark plug wires because when I first installed them the one on the left rear was exactly as you suggested and I fixed that.

It definitely is possible to be lean at higher rpm as I have not adjusted that yet. I have a Holley Jet assortment ready to use and may bump it up a few tonight.

 

[stappy]

Only vacuum leak I can find is the one at the headlight switch for the headlight doors. Just a slight hiss.
I do have a huge vacuum port tree in the manifold from the motorhome and it's massive vacuum booster but it is only going to the PCV valve.

 

[stappy]

Initial was around 13, mechanical 34
I do not remember vacuum as I was just happy it moved.

 

[moes]

get that AFG hooked up, nothing better then having current live information while driving the car.

 

[stappy]

Pulled the vacuum advance off and plugged the hose last night just for grins. No imporvement but some degradation. Actually noticed it seems to run funny at all speeds, just very noticable from mid-range up.
Unfortunately my TicTocTach does not work either so cannot tell what rpm. Actually half of my gauges do not work.

 

[pwDave]

Ok, so I have searched for a solution to my problem but I am sure I am just not diagnosing far enough.
I have a 1977 440 Motorhome engine in a 1969 Charger. I transplanted the whole thing electronic ignition and all. I have replaced the ignition control module (Oem style), coil (Accel yellow coil), all plug wires, new cap and rotor, new voltage control module (twice), Newer alternator, New fuel pump, New fuel tank, line, and sender, and new spark plugs.
Stappy, hate to admit this, but once upon a time I needed a distibator for my 440 in my truck, went to the shop and got the parts box out and started pulling parts out, put one together that wasn't loose and put it in. I drove that truck for several mo.s, and couldn't figure out why the damn thing was so sluggish upstairs, had the cap off one day looking at it again,(was working out of town) then noticed that the advance was pulling retard, WTF!! I had built a small block housing with a rb block shaft, went to the parts store and got a new rb block distribator. ran damn sight better after that!! felt like a DA, but you can't ever tell, whos been under your hood before you got there!! good luck with the miss and hope you find it. Dave.
Other notable points, I tried to rebuild the ThermoQuad and wound up making it sooo rich that eyes watered and could not breathe. I tried another Holley and same result. Tried a third and have been tinkering with that one now. I am not sure of High end jetting but idle and power valve should be good as well as all passages cleaned out. I have purchased an Air Fuel Gauge and I had O2 sensor bungs installed in the 2.5" duals that come off headers on the engine. I do not have that installed yet.

Here is the issue: At idle and low mid-range it seems to run great. At upper mid-range and beyond it develops a misfire that to me sounds like ignition. The car keeps accelerating though.

I had the distributor out and the weights were all frozen which I fixed with some penetrant and moving them back and forth. I also saw the vacuum advance plate was bent so I flattened that out and to me it looked like the vacuum advance arm was connected to the wrong place. There were two locations it looks like it could have been connected to so I put it in the other one. I did check timing and the mechanical advance is working as it should now and vacuum pulls it on further indicating that is also working.

What should I check next? What information should I be chasing down to determine the cause of the sputtering.
https://goo.gl/photos/8BuRhWS1JfGFJxu1A

p.s. I did put in new voltage regulator and the reading at the battery is around 13.7. It starts and always seems fully charged and headlights are bright at night. I have not chased it down as 13.7 is better than the 0 volts I battled for weeks only to find out a bad new voltage regulator.

 

[stappy]

Ok, so spent 2 hours the other night with a Holley jet assortment and some screwdrivers and set about to tune the carb. Float levels had been set previously and were still good. I added the Holley extension arm so it fit the Chrysler cable and kick down setup (best $15 bucks spent!) and then pulled the bowls and swapped out the jets to the recommended sizes for 300-400 horse (per Summit tuning video on YouTube ummmkayyyy).
The jets inside the carb were a jumbled mess. Mixed side to side with bigger jets in primary than in secondary. One side primary had 82 and the other 76.
Took it out for a drive and it ran much better. Smoother but a hesitation when accelerating. WOT was very cool.
Went back to the driveway and went up 2 jet sizes front and rear...
low speed not much noticeable difference but high end got better yet. Bigger hesitation now when opening the throttle but high end better yet.
Back to the driveway (this requires a 1.5 mile drive down dirt roads at 25 mph)
Check two plugs and evidence of running lean BUT under a layer of black. I am thinking this means WOT is still lean but low speed (1.5 miles of dirt at low speed) is either right on or rich. Thoughts??
Bad side, hesitation is even WORSE now. I checked the Holley setup manual and it suggests that I have the wrong spring in the accel pump diaphragm.
Thoughts?

 

[stappy]

New distributor on order! Should have it here tonight.

 

[moes]

the first thing I do is get the accelerrator pump working right, did you adjust the pump right, you might need a bigger accelerrator pump nozzle and then I would work on the jets next. check this video out from Holley.

 

[Jackpot50]

What about fuel filter and pump?
Lean at high RPM right?

 

[oldbee]

Staple you're going about it wrong, jets are the Last thing to change. Timing, acc pump are among the first; oh and NO vacuum leaks.

 

[stappy]

Staple you're going about it wrong, jets are the Last thing to change.

Well,,, as I said earlier Jets were NOT stock and were nowhere near correct. Way to fat and mix mashed in the craziest way. Like someone grabbed a handful out of a box and just stuck them in a random pattern. Low end is now running MUCH better. Installed a new distributor last night and that seems to have smoothed out some running.
BUT!!! The biggest thing was we installed an O2 sensor and a cheap Amazon Air Fuel Gauge. It showed that it is running rich at idle (easy screw turn) and you can drive around and be nice and fat. Once you give it some throttle BAM needle swings way way over to lean. Like 19:9 to 1 kinda lean (which is probably as far as the thing goes). If you stomp it it goes way lean, then back rich, and then at top end it sputters and starts showing lean again.

Next steps:
* Oldbee is correct about the accelerator pump and it is getting a new diaphragm
* Idle jets will be turned in for better reading but not going overboard worrying about it.
* Secondary jets will be bumped back up
* Vacuum secondary diaphragm will be replaced as it is crusty and nasty and probably not opening all the way
* Accelerator pump replaced
* Many Many more test runs... around and around the block. Gotta tick off the neighbors ;-)

 

[72RoadrunnerGTX]

I do have a huge vacuum port tree in the manifold from the motorhome and it's massive vacuum booster but it is only going to the PCV valve.

You have a PCV connected to the intake vacuum fitting? The PCV needs to connect to a balanced carb port intended for that purpose. Will have a lean condition on one runner with a PCV on that fitting.

 

[stappy]

You have a PCV connected to the intake vacuum fitting? The PCV needs to connect to a balanced carb port intended for that purpose. Will have a lean condition on one runner with a PCV on that fitting.

Ok.
I have one small port on the carb which is going to the vacuum advance. Should I stick it over there then?

 

[72RoadrunnerGTX]

What carb? I don't see where it's identified other than Holley. list number?

 

[69a100]

You don't say a thing about what year your car is, which Regulator you used and a few others.
Read this then tell us what's wrong!

Early Charging System modified for use with a 70 style VR

There are a number of reasons one might want to upgrade a pre-1970 system to a transistorized voltage regulator. The list of reason include

• Chrysler recommends you switch to a transistorized VR if you upgrade to an electronic ignition from a points style ignition.
• If you have to buy a new voltage regulator, the difference in cost is only about $5-10 more for the transistorized unit. Not to mention, the quality of replacement early style VR's is spotty.
• The transistorized VR will have a longer life.

Below is a diagram describing how to install a 70 and later Voltage Regulator on a sixties mopar.

http://www.imperialclub.com/Repair/Electrical/charging.htm

 

[coloradodave]

That Holley was probably jetted for a Chevy rat motor (big block). Unequal runner lengths required skewed jetting...