Ignition timing settings for 1978 Dodge Magnum 400 CUI

Hello everybody,

i have a Problem with my 1978 Dodge Magnum. She has the 400 CUI V8 Engine and Chryslers "electronic lean burn" spark Computer (new of stock replacement).
(and factory rebuid original 4bbl ThermoQuad installed)

It seems that the ignition Timing is not correct, because the car has very low Power and a to high fuel consumption.
It even stumble in IDLE.

But i dont find any values for the correct Timing in my carshop Manual.
On engine or Frame i dont find any "Emission Control" Sticker with Information.

Did anybody can tell me the Basic ignition Timing for my engine?

And maybe anybody can tell me something about how powerful this engine should be normaly?

She only comes to 11 mpg on a 60 miles an hour Highway ride. Are i am right that this is to mouch?

Sorry for my bad english.

Regards from Germany

Not sure if this may be your problem, but I had a 79 Dodge Magnum, and it ran good for a while, then started losing power, barely running, plugs kept getting fouled and so I finally discovered that the catalytic converter had gone bad, corroded or something and was clogging the exhaust. Once I put a new set of plugs in and took out the converter so the exhaust was clear, she ran 100 times better.

Not sure about timing, however, never been a fan of lean burn system, I know a lot of people have converted to standard electronic ignition, so hopefully someone that still works on these will chime in with some more suggestions.

If there are any timing specifications they will be located on the driver's side valve cover. Timing can not be set with a standard timing light.

Thank you for your help.

The car is from Ohio and has no catalytic converter in it (maybe not needed in 78 there or later removed).
There are no Information of any valve Cover, drivers Door or near fender tag as i know from Lincoln models. Maybe the stickers lost or been removed by previous owner.

I think the Ignition timing for IDLE is the same for conventional or ELB Ingnition. I have in Shop Manual all information how to short switches and vaccum etc. to do the correct alignment.
But in Manual there only reference to the "emission sticker" in the car.

The ELB seems to work correct, under load contiditons the timingmark do what i would expect, the iginition timing goes to pre ignition.

If allowed ditch the lean burn and install a normal electronic distributor and ECU. If that is not an option make sure the vacuum lines are all OK and hooked up correctly. Is the vacuum advance unit in air cleaner working?

Hello, i dont think that the Lean Burn System causes the Problem.
All Vaccum Lines are new and all vaccum Units are tested.
I hope i found the Problem. I replaced the electric heater for the choke release. I t seems that there two versions of it, one who is very stiff and release very slowly, and another one who has a more soft spring and opens in half the time.
Now i inserted the one with softer spring and did new Setup of the carburator (Costs me 170 Euros to do alignment in a "professional" Workshop) but i think they had no clue what they do, the IDLE-Mixture Screws was turned out 5 1/2 turns...
I did Setup by myself with 1 1/2 turns and found that 2 turns was good to have a good idle.
Found a Emission Control Sticker at Ebay for my model and the Timing seems to be correct.

Belive or not there is a timing form 24 Dregress BTC required and Timing Mark Shows between 22 and 24.
Never seen a normal Car with this Timing requirements in IDLE. I expected that so mouch pre ignition in a racecar, not in a car who has 4.200 RPM Max.

Does anybody now if this is a Tribute to the hemi Motor?

With new Setup she runs very mouch better, i think a Magnum never designed as a "tire burning" racecar, but acceleration is okay for me.
Havent had time fore a Long trip to look if Gasmilage was signifficant better now.

Does anybody now if 15MPG is a realistic value for fuel consumption to a 400 CUI?

Just a few comments on your 400 since your post. Your carb is the original carter with large secondaries. Set the ideal to the point where the RPM drops 50 RPM'S. back off one turn, this is a good starting point, some say a 1/4 is the best but in part it depends on other factors. The secondaries have a tension screw with a internal spring. Its normal takes a special tool to set the secondaries. The best way to set up the carb is trial and end. You have to drive the car and set to the secondaries based on the bog or drop point. Simply put you can feel the acceleration or transition to gain power without the engine dropping in power or acceleration. Initial timing is based on elevation and overall timing. Advance the initial to about 11-15 degrees. If it starts and does not ping at under acceleration you are close. Lean burn is designed to control timing advance based on air intake or flow. As your driving more air is feed to the system. The problem with most setups is the air duct system has been removed from the grill to the air cleaner. If your duct is gone, take it out , you never have correct timing advance. It short it controls the distributor timing. Yes 15 MPG is normal. Your ride is heavy. Gear or rear end ratio will determine acceleration and mileage. A typical gear ration is 2.76-2.92. depends on rear end type, but these gears are designed for the highway not acceleration. If you want more acceleration, change to 3.31. Again you may want to locate a different rear end and change out the entire unit to make the change. If you want a deeper set up, find a truck or ram charger rear end as a doner. Good luck

Some "Lean" info here.....................

http://www.mymopar.com/index.php?pid=433

http://www.hamtramck-historical.com/dealerships/1978DealershipDataBook-01.shtml