....data from Tunerpro is telling me that while under boost, my AFR are leaning out. This is also confirmed by the the fuel pressure guage. As boost increases pressure decreases. The fuel tables being used under boost are maxed out (99.61), so I tried adjusting the F77X table but they are still leaning out. So I installed a new walbro 255L hours ago and pretty much still get the same thing again even after adjusting the F77X table. Fuel pressure is set at 45#. A little help would be appreciated.
Tuning...
- Thread starter Ellis
- Start date
WyoSyclone
Active member
Re: Tuning...
Did you put in a new filter also? Take FP up to 48.
Checked for vacuum leaks??
Did you put in a new filter also? Take FP up to 48.
Checked for vacuum leaks??
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Re: Tuning...
...actually I did the fuel filter thing first. I'll try a little more fuel pressure.
...actually I did the fuel filter thing first. I'll try a little more fuel pressure.
Big Mike
New member
Re: Tuning...
Maybe adjust your f28 table to get your f29x numbers lower, what are your f28 table numbers, mine are 168, of course all of your table will need to be re tuned or you may use the tool box and take the numbers down. What base bin did you start with? Did you adjust the f28 table to get it to idle good or did you adjust the f29x table first? Numbers on my f29x table are between 23 and 50.
Maybe adjust your f28 table to get your f29x numbers lower, what are your f28 table numbers, mine are 168, of course all of your table will need to be re tuned or you may use the tool box and take the numbers down. What base bin did you start with? Did you adjust the f28 table to get it to idle good or did you adjust the f29x table first? Numbers on my f29x table are between 23 and 50.
Re: Tuning...
hmmmm.....never thought about adjusting the F28 table for that kind of result. My F28 table is 120. I'm also not familiar with the tool box function. I started with Syclonerob bin which I believe was for #50's....can't remember off hand. With respect to idling; I started with the F28 table first. The values in my F29X table range from 45 - 99.
ZavzTy547
Senior Member
Re: Tuning...
Try using a bin for the stock fuel injectors to see if you run rich and start gradually leaning it out....
Also, you want to make sure your in open loop?
Can you verify if this table - PE AFR VS RPM (F61) changes anything? I was having similar issues and suspect this table as a possible fix (my trucks on blocks so I can not test).
Let us know!
Z
Try using a bin for the stock fuel injectors to see if you run rich and start gradually leaning it out....
Also, you want to make sure your in open loop?
Can you verify if this table - PE AFR VS RPM (F61) changes anything? I was having similar issues and suspect this table as a possible fix (my trucks on blocks so I can not test).
Let us know!
Z
dgoodhue
BuSTeD 4.3
Re: Tuning...
Maybe this is just a typo, but as you boost increases your FP should be increasing. So with you 45psi base FP, you should see 60psi at 15psi of boost. If it isn't you have an issue with your fuel system.
Maybe this is just a typo, but as you boost increases your FP should be increasing. So with you 45psi base FP, you should see 60psi at 15psi of boost. If it isn't you have an issue with your fuel system.
BoostedSUV
Active member
Re: Tuning...
I was thinking the exact same thing when I was reading through all this. Sounds like your pump isn't keeping up with demands. Could be a volume issue and not a tune issue. Try setting the base FP to 50 and see if that stabilizes the fuel pressure under boost load. If it doesn't I would lean more towards the fueling system over tune.
I was thinking the exact same thing when I was reading through all this. Sounds like your pump isn't keeping up with demands. Could be a volume issue and not a tune issue. Try setting the base FP to 50 and see if that stabilizes the fuel pressure under boost load. If it doesn't I would lean more towards the fueling system over tune.
Re: Tuning...
..I'll take it under advisement. At this point I probably need to be open minded.
..I'll take it under advisement. At this point I probably need to be open minded.
Re: Tuning...
...that would be correct and not a typo; as my boost increases and depending how hard I'm laying into it the fuel pressure slowly increases with boost and then decreases as the boost psi increases. This is confirmed through Tunerpro with AFR rising as high as 16 with about 12-14 pounds of boost. I too am leaning towards the pump not keeping up and have yet to try turning up the pressure. But with me getting out of work late and it being dark out and cold; I'll have to keep you guys posted.
turbodig
Active member
Re: Tuning...
Fuel pressure should increase with every additional pound of boost. If it isn't, either the regulator is bad or the pump is faulty. (or not getting enough voltage)
Adding additional fuel in the chip won't do anything if fuel pressure isn't maintained.
Fuel pressure should increase with every additional pound of boost. If it isn't, either the regulator is bad or the pump is faulty. (or not getting enough voltage)
Adding additional fuel in the chip won't do anything if fuel pressure isn't maintained.
Re: Tuning...
...right now I'm not willing to acknowledge the pump is bad for two reasons. The first is because it's new and the second reason is because I was experiencing the same problem with the stock pump. So tell me; is there a way to check for a bad regulator and a way to check for "enough" voltage? By the way I do appreciate all the responses.
...right now I'm not willing to acknowledge the pump is bad for two reasons. The first is because it's new and the second reason is because I was experiencing the same problem with the stock pump. So tell me; is there a way to check for a bad regulator and a way to check for "enough" voltage? By the way I do appreciate all the responses.
WyoSyclone
Active member
Re: Tuning...
There has been a bunch of bad (knockoff) Walbro pumps in the market during the past year... if you bought an eBay pump from someone you don't know it could be a knock off... I know our SyTy vendors sell the real ones.
To test the regulator I guess you could get a Mighty-Vac hand held pump, remove the vac line from the regulator, and increase the pressure by a few pounds.. if you have a FP gauge it should show an increase in fuel pressure.
The only way I know of to check for the voltage is to tap into the wiring at the tank, run the leads up to the cab, and hook a voltmeter to them and see if you get voltage sag as your boost builds... this would indicate lack of current at the pump.
There has been a bunch of bad (knockoff) Walbro pumps in the market during the past year... if you bought an eBay pump from someone you don't know it could be a knock off... I know our SyTy vendors sell the real ones.
To test the regulator I guess you could get a Mighty-Vac hand held pump, remove the vac line from the regulator, and increase the pressure by a few pounds.. if you have a FP gauge it should show an increase in fuel pressure.
The only way I know of to check for the voltage is to tap into the wiring at the tank, run the leads up to the cab, and hook a voltmeter to them and see if you get voltage sag as your boost builds... this would indicate lack of current at the pump.