Wideband/Running lean issue
Going to try and get it on my buddies dyno here sometime with a mechanical gauge. I do have a cheap fuel pressure guauge so it's possible it could be going out. However, that still doesn't explain why two different widebands show it going lean up top.
I have saved every log I have taken and have reviewed from past logs. If fuel pressure was really rising, and I have tried adding up to 30% fuel, I would think it would run like a dog. It still pulls hard and shows lean.
More tests to be done this week at some point. I appreciate all the help and insight. I will find the cause eventually.
I have saved every log I have taken and have reviewed from past logs. If fuel pressure was really rising, and I have tried adding up to 30% fuel, I would think it would run like a dog. It still pulls hard and shows lean.
More tests to be done this week at some point. I appreciate all the help and insight. I will find the cause eventually.
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Joined: Nov 2003
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From: Norn Iron
A 30% increase in IJPW would more than compensate for that static fuel pressure. That increase in injector opening...if it actually happened should have caused a huge drop in AFR's ( numerically )
I assume IDC's are not already at 100% ?
Does HPT or whatever you are using, actually record final injector pulse width ?
I assume IDC's are not already at 100% ?
Does HPT or whatever you are using, actually record final injector pulse width ?
Duty cycle is not at 100%. It does increase as I try to add more fuel. FWIW, last year at the track when I ran my 9.92, I was on 14 lbs. of boost. Injector duty cycle was around 80%. This year, on about the same boost level, after I try adding more fuel, duty cycle was in the 90% range. Almost touched 100% at one point during a few runs.
If it was really getting the fuel I was throwing at it, then the AFR should have taken a huge dive like you mentioned.
After doing some research on HPT forum, it appears that the pulse width figure on the scanner is the real time PW. It's the final product after all the adders and subtractors.
If it was really getting the fuel I was throwing at it, then the AFR should have taken a huge dive like you mentioned.
After doing some research on HPT forum, it appears that the pulse width figure on the scanner is the real time PW. It's the final product after all the adders and subtractors.
9 Second Club
Joined: Nov 2003
Posts: 13,616
Likes: 185
From: Norn Iron
30% increase in fuel for only a 10% increase in duty ? those numbers dont add up....combined with rising AFR's
Nothing adds up here.
The drop in fuel pressure alone...as it is very small or almost non existent isnt necessarily enough to justify the leaning AFR's
A raise of 30% in IJPW is absolutely massive. For that not to make a "rich" change to AFR's is unbelievably strange, even with the fuel pressure issue.
Nothing adds up here.
The drop in fuel pressure alone...as it is very small or almost non existent isnt necessarily enough to justify the leaning AFR's
A raise of 30% in IJPW is absolutely massive. For that not to make a "rich" change to AFR's is unbelievably strange, even with the fuel pressure issue.
I am not sure how duty cycle is actually calculated in the software.
The fuel pressure drop is not real significant at lower boost levels. The more fuel demand there is, the more pressure drop I have seen.
I apologize, it's not a 30% rise in IJPW. I have added ~30% fuel in the VE table. No matter what I do in the VE table, above 180kpa or so, adding fuel makes no difference. Below that I can get it to start going rich as the kpa level is not that high, but above that mark it makes no change.
When I get a chance to work on/drive it again then I will take some video of the gauges to show what I am seeing. I will try it at the different boost levels, log it, video it, and post that information up here.
The fuel pressure drop is not real significant at lower boost levels. The more fuel demand there is, the more pressure drop I have seen.
I apologize, it's not a 30% rise in IJPW. I have added ~30% fuel in the VE table. No matter what I do in the VE table, above 180kpa or so, adding fuel makes no difference. Below that I can get it to start going rich as the kpa level is not that high, but above that mark it makes no change.
When I get a chance to work on/drive it again then I will take some video of the gauges to show what I am seeing. I will try it at the different boost levels, log it, video it, and post that information up here.
9 Second Club
Joined: Nov 2003
Posts: 13,616
Likes: 185
From: Norn Iron
That's part of my question.
You're adding 30% in a fuel table. Does this correspond to a longer injector opening of 30%
Logging should tell you this quite clearly.
ie...it may have been 10ms before, now it's 13ms ?
At least that would give you some indication the injectors are doing what you ask.
You're adding 30% in a fuel table. Does this correspond to a longer injector opening of 30%
Logging should tell you this quite clearly.
ie...it may have been 10ms before, now it's 13ms ?
At least that would give you some indication the injectors are doing what you ask.
Ok, so I feel like an idiot. It was a pinched feed line. It must have happened when I put the trans pan back on after doing a fluid and filter change. We had plans to put it on the dyno today to start trouble shooting and a buddy looked under the car and noticed the line. All is well now.
I feel incredibly stupid but that's the name of the game at times. At least it's back to running and doing what it should. Thanks to everyone in here that posted up advice. It's greatly appreciated.
I feel incredibly stupid but that's the name of the game at times. At least it's back to running and doing what it should. Thanks to everyone in here that posted up advice. It's greatly appreciated.
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