How do i get the pcm to command more fuel out of the injectors?!
i have the PE table maxed out from 5600+ at 49.6..i already messed aroudn witht he coolant temp vs afr table without much change......i thought i was running out of injectors (had 75lbs) so i got some 95 lbs and the problem got even worse! With 75lb injectors i was hittin around 75% duty cycle, i swaped in the 95s in hope that i will still get 75% duty cycle, but NO!!! i get less then 60% !! What in the world is going on!?!? someone help!

 

I think you are going the wrong way on injector sizing. The bigger they are, the less duty cycle they will need to put out the same amount of fuel.

 

Right, if you wanna increase duty cycle then you need a something under 75lb.

 

well in theory the 75lbs injectors at 100% duty cycle should provide enough fuel for my car....so by goin to 95lb injectors i should be at 80% duty cycle...the problem here is I CANT NOT get the PCM to give me that fuel!!!

 

I think this may be an OBD1 thing. Why don't you PM LJ and ask if it might have something to do with the Versafueler.

 

well ok...lets froget about the duty cycle..which tables control the fuel in the PCM...I AM NOT GETTIN ENOUGH FUEL even though the PE table is maxed out..

the fuel pressure does not drop its steady at 60+psi under WOT so the pumps are giving planty of fuel, its just PCM is not giving enough fuel

 

I dont understand what you are doing. You said the 75lb injectors were only 75% duty cycle so why not just leave it at that? In theory yes if you had 100% duty cycle with the 75lb injectors then its safe to assume the 90lb would be 80% but the 75lb arent 100%... they are 75%.

 

well 75lbs injectors at that duty cycle were not giving me enough fuel , since i have PE table maxed out and are gettin only 75% duty cycle something is holding the fuel back......fuel pressure is at 60psi+ at wot so its deffinitly not the dual walbros....i was hopeing that if i swaped to 95lb inejctors i would stil be able to get around 75% duty cycle, but no matter waht i cant get it to go past 60%...

 

Alright I see what you are trying to do.. sounds like the computer is holding you back. There are other ways of increasing fuel such as increasing the MAF values you see at WOT. Sounds like you might be needing a PCM that can handle the changes needed for your setup.

 

jeff is making 800+ rwhp with a same setup with a STOCK pcm...

i would like to know all the way to get the pcm to dump more fuel..please list them

 

Alright the others arent the best b/c you get fuel but you get fuel in every driving situation. Basically lower the injector constant or raise fuel pressure. Those two are the big ones but like I said you get rich all over instead of high RPMs where you want it.

But what you may be able to do is lower the BLM boundary to its lowest value... then the PCM could still compensate.

Another thing to try is bumping up the minimum integrator value to say 140 to start. That could prevent the PCM from pulling fuel. I forget the formula for calculating the fuel demanded by the PCM but I do believe it uses teh integrators instead of the BLMs.

 

where do i find this integrator value u speak about?


nm i think u are talkin about BLMS....

 

Latest versions of the TC def files in the PCM constants.

 

Nowhere in the thread is an actual problem described, but I'm going to go out on a limb and assume that you are running lean with the fuel tables maxed out.

If that's the case and if it isn't something broken that's causing this, then increase the fuel pressure.

 

There is nothing in this thread that says why you think you are not getting enough fuel.