There's no way that you should have to max out a chip burned for your combo. What are your block learns at cruise.
Will Increasing Fuel Pressure Increase O2 Readings
- Thread starter mmarlett
- Start date
There's no way that you should have to max out a chip burned for your combo. What are your block learns at cruise.
When people talk about O2 numbers we need to be specific. Are you saying that when you start from a stop and run through 1st 2nd and 3rd that your O2s drop to 800 by the end of third at 100 plus MPH,or are you saying that the number you observe is when you floor it in third for a little bit?
increasing the base fuel pressure isnt always the smart thing to do! you need to know what your pump flows at certain boost levels as the pump pressure drops off at higher boost levels. thats why its better to increase in the chip. if your at 43 line off and running 20 psi thats 63 psi well if the pump flows 150 there it will flow 120 at 25 psi so moving up the base lowers the flow numbers on a graph.
So does increasing the duty cycle. The only thing that matters is ,if you have a base of 45 and are running 20 lbs of boost and have 65 lbs of fuel pressure when you do that,you're OK.
northerngn
Master Monkeywrench
- Joined
- Oct 8, 2006
Let's not forget as pressure goes up volume goes down...Do you have this issue do to lack of pressure of lack of volume...
spend 12 bucks and slap in a new fuel filter and recheck...
spend 12 bucks and slap in a new fuel filter and recheck...
Ttype6 said:
That is a 100+ mph recall on the scanmaster.
Fuel filter is a Napa gold with 3k miles on it....chip was cranked before fuel filter replacement.
Not trying to hijack the thread but it sounds like we have the same problem.
Sent from my DROIDX using Turbo Buick. please mind the auto-correct
If,as you say,you've noted that the fuel pressure rises as it should you don't have a fuel delivery problem.
Did you ever try running the chip at the default settings?
this in addition to saying he wanted to be conservative due to stories about blown head gaskets....still waiting to hear from the op as to whether he actually has a problem or not..................
Chip at default settings has o2's around 700 at WOT with KR
It's incorrect to say I have a pressure problem because low pressure is caused by low volume. The more accurate statement would be to say I have a fuel delivery/volume problem.
The output volume of an electric fuel pump remains constant at any given voltage.
Yes,as the motor consumes more fuel the pump will eventually not be able to keep up.Whether you turn the injector on for a longer period of time or increase the pressure,the pump will eventually not be able to keep up. As we do this the pressure starts to fall because of lack of volume. The problem of low pressure is caused by two things generally. The first thing is an incorrectly set or defective regulator. The second thing is a lack of volume caused by an inadequate pump or a pump not receiving enough voltage, or a restriction in the fuel delivery line. As long as pressure rises as it should,none of these things have become a problem yet.
The only thing that matters is correct pressure rise.If we have this we know we don't have a fuel delivery problem and we can look elsewhere.
The OP hasn't confirmed or disproved correct fuel pressure rise so we don't know yet if he has a fuel delivery problem,so we can't yet advise the replacement of the fuel filter.
Nor Easter says his fuel pressure is rising as it should,so he doesn't need a fuel filter.
As long as you can see good O2s,and you are,I'd say you don't have a problem. It's not right that you have to richen it up so much. If your O2 sensor is a little off the chip can learn wrong. Sometimes funny things happen to the learn process that a re-boot can fix. These two thing are something to think about. However, you are able to see good numbers with no ignition retard. That's the real goal.
northerngn
Master Monkeywrench
- Joined
- Oct 8, 2006
kind of contradicting statements
well which one is it
I'm pretty sure a fuel pumps output at 10 volts is different than at 15 don't ya think?
I don't think a quick voltage check at the pump harness running vs the back of the alt wouldn't be a bad idea...
WOW! Alot of insight.
I have not been able to check WOT and fuel pressure rise through 3rd gear; I hope to do this in the next few days and respond. From what I have read in this thread, this is a criticle step.
I will also try going back to chip default.
I will keep the group posted.
Again, thanks for the great information!
Matt
I have not been able to check WOT and fuel pressure rise through 3rd gear; I hope to do this in the next few days and respond. From what I have read in this thread, this is a criticle step.
I will also try going back to chip default.
I will keep the group posted.
Again, thanks for the great information!
Matt
he did say output remains constant at any given voltage, meaning, for example at 10 volts=30 psi, at 15 volts=45 psi...just for example...so if you're voltage WAS low, obviously your pressure would be low...kind of contradicting statements
well which one is it
I'm pretty sure a fuel pumps output at 10 volts is different than at 15 don't ya think?
I don't think a quick voltage check at the pump harness running vs the back of the alt wouldn't be a bad idea...
and again......did you actually have a problem, or just being overly paranoid??
kind of contradicting statements
well which one is it
I'm pretty sure a fuel pumps output at 10 volts is different than at 15 don't ya think?
I don't think a quick voltage check at the pump harness running vs the back of the alt wouldn't be a bad idea...
You said as pressure goes up volume goes down. That's not true. The volume of a pump never changes at any given voltage. I've already said that and gave a very detailed explanation. I never said in one statement that pressure was the problem,then in another say volume was a problem. I also talked about how voltage has a direct effect on pump output volume and you respond as if I didn't even realize this fact. Please explain how I contradicted myself.
Again we have one person who has confirmed pressure rise and one who has yet to report his. Certainly the confirmed one has no need to check voltage because he doesn't have a fuel delivery problem. The other one hasn't yet determined that he has a fuel delivery problem so why would he check voltage. I,m waiting for him to report back. Then,if his pressure doesn't rise correctly,voltage would be one of the next things to check.
After re-setting to default I want you to re-install your max fuel adjustment then drive the car and see if you note some different numbers.
I still want you to first check pressure rise.
He certainly has a problem. He can't run 16 lbs of boost without spark knock and after adjusting his chip to its richest setting he still has low O2 numbers.
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