Running extremely rich Help?
03-31-2008, 10:44 PM
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Running extremely rich Help?
I installed a front mount intercooler, 255lph fuel pump and a new fuel filter this weekend and now my truck is running extremely rich. I don't think the intercooler has anything to do with it but you never know. My fuel pressure went from 48psi at idle to 52-54psi with the new pump so I am assuming that is the problem. My truck does have a regulato on it so it goes up to about 62-64psi at WOT. My LTFT's are at -15% now and if I go into PE my A/F goes to full rich on my wideband which is below 10 to 1. I tried scaling back my VE table with EFI Live but it didn't really do anything but make my truck run worse. Please help. At this point I am almost scared to drive my truck to work.
03-31-2008, 11:08 PM
#2
I installed a front mount intercooler, 255lph fuel pump and a new fuel filter this weekend and now my truck is running extremely rich. I don't think the intercooler has anything to do with it but you never know. My fuel pressure went from 48psi at idle to 52-54psi with the new pump so I am assuming that is the problem. My truck does have a regulato on it so it goes up to about 62-64psi at WOT. My LTFT's are at -15% now and if I go into PE my A/F goes to full rich on my wideband which is below 10 to 1. I tried scaling back my VE table with EFI Live but it didn't really do anything but make my truck run worse. Please help. At this point I am almost scared to drive my truck to work.
03-31-2008, 11:14 PM
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If I take fuel out of PE it will not fix the whole problem. I need to get my LTFT's back to normal which should fix WOT as well, right? Right now my PE is set to 11.9 so it shouldn't be running below 10.0 to 1 unless there is a serious issue. My AFR and fuel trims were spot on until I installed these upgrades.
04-01-2008, 07:10 AM
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I installed a front mount intercooler, 255lph fuel pump and a new fuel filter this weekend and now my truck is running extremely rich. I don't think the intercooler has anything to do with it but you never know. My fuel pressure went from 48psi at idle to 52-54psi with the new pump so I am assuming that is the problem. My truck does have a regulato on it so it goes up to about 62-64psi at WOT. My LTFT's are at -15% now and if I go into PE my A/F goes to full rich on my wideband which is below 10 to 1. I tried scaling back my VE table with EFI Live but it didn't really do anything but make my truck run worse. Please help. At this point I am almost scared to drive my truck to work.
O.K first off, was anything done to the regulator?
If all you changed was the pump and filter, your fuel pressure should not change. If you did see and increase in fuel pressure you will need to rescale the injectors for the new flow rate. The computer doesn’t have any way to verify fuel pressure; it relies on the regulator to do its job. So if you now have more psi of fuel behind each injector, each stroke of the injector plunger now has 53psi of fuel to be injected instead of 48. That is why it is rich. Be sure to keep pressure and flow separated in your mind, they are different. lol
So, rescale the injector table and recheck your tuning. You can adjust all the "other" tables like the maf and v.e table, but keep in mind, the injector table is one of the "base" tables that a lot of the other fuel calculations are made from. So if you are off a little in the injector table you will see a variance in the a/f ratio when you command it whether it is 14.6 or using the P.E table and commanding 11.5......
The P.E is just that Power Enrichment. The PCM was pulling 15% of fuel with the LTFT's then, the PCM went into p.e mode. It just used your p.e values, even though the "base" injector table was off, so your air fuel ratio was too.... still with me?
You can adjust the p.e to lean out the a/f but if your fuel trims are correcting anything over 5% you really need to get the closed loop fueling fixed first before moving on to open loop (P.E)....
Are you still running maf?
Did it get pluged back in after the front mount install?
04-01-2008, 10:13 AM
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O.K first off, was anything done to the regulator?
If all you changed was the pump and filter, your fuel pressure should not change. If you did see and increase in fuel pressure you will need to rescale the injectors for the new flow rate. The computer doesn’t have any way to verify fuel pressure; it relies on the regulator to do its job. So if you now have more psi of fuel behind each injector, each stroke of the injector plunger now has 53psi of fuel to be injected instead of 48. That is why it is rich. Be sure to keep pressure and flow separated in your mind, they are different. lol
So, rescale the injector table and recheck your tuning. You can adjust all the "other" tables like the maf and v.e table, but keep in mind, the injector table is one of the "base" tables that a lot of the other fuel calculations are made from. So if you are off a little in the injector table you will see a variance in the a/f ratio when you command it whether it is 14.6 or using the P.E table and commanding 11.5......
The P.E is just that Power Enrichment. The PCM was pulling 15% of fuel with the LTFT's then, the PCM went into p.e mode. It just used your p.e values, even though the "base" injector table was off, so your air fuel ratio was too.... still with me?
You can adjust the p.e to lean out the a/f but if your fuel trims are correcting anything over 5% you really need to get the closed loop fueling fixed first before moving on to open loop (P.E)....
Are you still running maf?
Did it get pluged back in after the front mount install?
If all you changed was the pump and filter, your fuel pressure should not change. If you did see and increase in fuel pressure you will need to rescale the injectors for the new flow rate. The computer doesn’t have any way to verify fuel pressure; it relies on the regulator to do its job. So if you now have more psi of fuel behind each injector, each stroke of the injector plunger now has 53psi of fuel to be injected instead of 48. That is why it is rich. Be sure to keep pressure and flow separated in your mind, they are different. lol
So, rescale the injector table and recheck your tuning. You can adjust all the "other" tables like the maf and v.e table, but keep in mind, the injector table is one of the "base" tables that a lot of the other fuel calculations are made from. So if you are off a little in the injector table you will see a variance in the a/f ratio when you command it whether it is 14.6 or using the P.E table and commanding 11.5......
The P.E is just that Power Enrichment. The PCM was pulling 15% of fuel with the LTFT's then, the PCM went into p.e mode. It just used your p.e values, even though the "base" injector table was off, so your air fuel ratio was too.... still with me?
You can adjust the p.e to lean out the a/f but if your fuel trims are correcting anything over 5% you really need to get the closed loop fueling fixed first before moving on to open loop (P.E)....
Are you still running maf?
Did it get pluged back in after the front mount install?
I am still running MAF and it is plugged in. I even swapped my spare in to make sure that I didn't damage it when I was installing the intercooler.
I raised my IFR by 5% this morning which brings my IFR value to 46.4. It helped a little but my LTFT's were still around -11%. What should my IFR value be for Delphi 42lb injectors and a base fuel pressure of 53psi?
04-01-2008, 10:30 AM
#7
Forget messing with all of those supplemental tables.
The delphi's are I think 48.5 at 58psi. Which if correct is what you should use, meaning 58psi.
Something is wrong (meaning the previous low fuel pressure). Your new pump, I am guessing it is an inline? Or did you replace the in tank?
Change that IFR to 48.5 and report back.
The delphi's are I think 48.5 at 58psi. Which if correct is what you should use, meaning 58psi.
Something is wrong (meaning the previous low fuel pressure). Your new pump, I am guessing it is an inline? Or did you replace the in tank?
Change that IFR to 48.5 and report back.
Last edited by dewmanshu; 04-01-2008 at 10:37 AM.
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04-01-2008, 10:39 AM
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Forget messing with all of those supplemental tables.
The delphi's are I think 48.5 at 58psi. Which if correct is what you should use, meaning 58psi.
Something is wrong (meaning the previous low fuel pressure). Your new pump, I am guessing it is an inline? Or did you replace the in tank?
Change that IFR to 48.5 and report back.
The delphi's are I think 48.5 at 58psi. Which if correct is what you should use, meaning 58psi.
Something is wrong (meaning the previous low fuel pressure). Your new pump, I am guessing it is an inline? Or did you replace the in tank?
Change that IFR to 48.5 and report back.