something bad wrong with my timing

[lifted1981]

so i put a mopar performance ignition upgrade in my 74 scamp 318. It already had electronic ignition so i put the new dizzy and the orange box in with the stock wiring as the instructions said to do. I am pretty new to dizzys and carbs and such so bear with me.

if i adjust the timing for highest idle its at like 33* advanced i didnt even dare drive it like this

if i adjust the timing to 15* advanced the car idles ok, but backfires trough the carb, sputters, and tries to dies when i drive it.

if i set it to 8* advanced it starts getting real hard to start and will sputter and try to die when i drive it(the backfires are less at this point)

if i set it to 5* advanced it pretty much wont even start

the moter is a 318 with eagle forged pistons, 360 heads, lunatti cam with .495 of lift, edlebrock intake, and carb. should be about 9:6:1 comp ratio.

 

[63dartman]

We need more info.....Are you using the timed or ported vacuum port on the carb? Did you plug the vacuum advance ports on the manifold and dizzy when your checking the advance? Do you know how much vacuum your pulling? Make sure the orange box is grounded well and all wiring is connected correctly.

 

[1wild&crazyguy]

you'll need at least 18-20* initial for that cam, then you wanna end up with 30-34* or more if the cylinder pressures are low for the cam.

you need to find out [by removing the dizy cap] if it has the mopar performance adjustable dizy in it, you'll see adjustment screws on an anodized plate.
If it does have the mopar unit, you can adjust it to only allow a certain amount of mechanical advance so that you can run a higher initial [like I mention above] without having too much total/mechanical advance.


no that distributors have weights inside the as rpm increases, advances the timing around 20-25* [typical factory dizy example]

so if the motor likes 22* at idle[initial timing] and then runs best with 30*total [example] you'll want to limit the weights travel to only allow 8* mechanical advance.

you'' have to weld up the slots in the weights to limit the advance if it not an adjustable unit.fyi

 

[Purple Haze]

Sounds like you got some crossed wires, it should start run and not backfire even at TDC. I would check your firing order and then set timing to factory specs and go from there. Might have also jumped timing.

 

[redfastback]

Check for vacuum leaks.

 

[lifted1981]

i did plug both the carb, and the dizzys vac ports when checking it.

i am using the vac port on the front passenger side of the carb.

its a new rebuild with less than 500 miles. it worked fine before the mopar performance dizzy and orange ecu, so i doubt it skipped timing.

i think(and could be wrong) but a motor with a hot cam, and higher compresion than stock would need a little more than tdc base timing to run correctly.

i had it intialy at 22* base (i know to much but it was a mistake with the timing light.) it accelerated fine, but when i let off the gas it seemed like all 8 cyl would back fire one ofter the other trough the tail pipe. so i am thinking maybe my total timing is wrong. how do i set it?

 

[lifted1981]

so my plan of action is to go buy a stock dizzy, and put it on with 18* base untill i can learn enought o adjust the mopar one correctly.

 

[pettybludart]

Have you brought it to TDC to make sure your rotor is pointing towards 3!?You may have dropped the dizzy in,off by a couple teeth.Will give you odd settings.Good luck.

 

[lifted1981]

Have you brought it to TDC to make sure your rotor is pointing towards 3!?You may have dropped the dizzy in,off by a couple teeth.Will give you odd settings.Good luck.

i taught it should be pointing at 1? the dizzy is sloted it only goes in two ways, how could i be a couple off? wouldnt it be right or 180 off?

 

[daliant]

Stock damper? The outer ring could have spun causing the timing marks to be alittle off, just a thought.