Back tidle problems again

Have you pulled KOEO and KOER codes or just thrown parts at it? If you have what codes do you get?

So you are running a stock ECU on a 331? We need to know a lot more about the build. Things like what:

Injectors
Mass air meter
Fuel pump
Cam shaft
Heads
Etc

As much as you can list will help.

The tables in the ECU are set up for a motor that moves the air volume of a 302 so I would say that without a tune it’s not going to run optimally.

Well if the camshaft specs are unknown it can be known by using a dial indicator but from what I see your car needs to run in open loop always given the LT hedders and no wideband controllers and another chip like a QH is definately needed...........



Heres the difference between my camshaft specs (Explorer cam) and injector timing numbers(top numbers) in my engine and whats in the stock A9L tune(bottom numbers) as Im running a 93 351w on an A9L w/QH


Knowing when your exhaust valve closes and the intake opens is important in dialing in the timing of the injector to the valve actions at idle or youll get a wet intake manifold and a hard to nail down lambda...

Most hard start situations are caused by the cylinders literally hydrolocking during a hot startup due to inconsistent spraying due to improper injector spray commands...........


Heres when the injectors spray in an X3Z tune (bottom numbers).............



Alls it takes is a dial indicator and a magnetic base and you can also use it to check your pushrod angle to see if the pushrods are too long or too short.



As far as the stalling etc it all needs to be adjusted in the tune..................Everything on the left is my tune and stock A9L on the right...









Good Luck