Throttle body CFM VS engine Cubic inches?
Quote from ajax-1947 on October 13, 2020, 6:21 pmA huge vacuum leak would have the engine running extremely rich which would be evident by the appearance of the spark plugs, spraying starter fluid or whatever seems to make little difference as it is already over fueled, a smoke test is the surest method to use ( speaking from experience).
Wouldn't a vacuum leak cause it to be lean or AFR trim to be high as its trying to add more fuel to cover the extra air from the leak? But plan on going to my buddy shop this weekend to do a smoke test.
Is AFR learn % is equal to long trim fuel trim? I'm used the tuning my charger with HP.
I just loaded the default tune, set cubic inches to 360, cam 1. It would fire for a few seconds then die. I finally got it to idle by setting the AFR learn to 99%, and AFR learn settled to around 75% and trim around 0%, So my question would be, is 75% AFR learn bad? Will it go down as the system learns. I am used to logging EQ error and taking it out of the VE table. 75% seems like it would be a lot. Data log of it idling.
https://docs.google.com/spreadsheets/d/1S8N9bbeK3DPAIGqmGpT8FcIIyw08eo4OH3hzyHcrhbs/edit?usp=sharing
With a carby yes, but with the efi throttle body, with the extra air from the vacuum leak the O2 sensor says its lean and adds extra fuel to compensate, on top of the fuel it is already supplying.
Sorry I can't help with the other, I'm more of a mechanical person.
well I got a fuel pressure gauge installed today. I'm only getting 6 psi. I have a hyperfuel in tank pump. i even capped the return line and still only got 6 psi.
Good news, at least that explains why you are having trouble.
- Make sure you have 12 volts to the pump, if not, put your own constant 12 volts on it and check pressure gauge
- What is the rated pressure of the pump at flowrate?
- If you put voltage on the pump and still not getting pressure at the gauge, then
- bad pump?
- plugged filter?
- fuel line restriction?
- bad gauge (it's happened before)
it should be 43psi. What you said is what I planned on doing. But work gets in the way.
If I don’t get 12v bad ECU or ground?
I did set PWM to 99% to make I was getting the pump to run.
you need to physically check the voltage at the pump with volt meter, could be either bad hot wire or ground, check both.
I know. Just meant the ecu control voltage. The pump runs. But if I’m only getting say. 8 volts at the pump, with a good ground. Then id think the ecu probably.
or bad connections. If I were you, I would first force 12 volts right at the pump power wire and check your pressure, but I'm not you so do what you want. I'd like to know if my pump and gauge were working first.
That was what I planned on doing. I know the pump is running. I have been driving it. Just sucked when I’d give it more then 50% throttle.
Ok, good luck.