When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I know I haven't posted in a while, but today I have an update.
I removed my MAF and air filter from the pipe that feeds the turbo. I put a PVC pipe plug in the end, drilled a hole and connected up my smoke-testing machine. This tool worked great. I found that there was smoke pouring out of the coupler that goes between the turbo intake and the pipe that feeds it. My recirc pipe also had smoke coming out of it too, so it was pulling in un-metered air there as well. I took everything apart, put it back together and re-smoke tested it. No leaks. I started the car expecting the short-term fuel trim to immediately go negative to counter the +12.5% long term, but It didn't.
At this point the car was very, very low on fuel. Like on the bottom line just above the letter "E". My ethanol gauge was reading 80% ethanol, and the yellow "low fuel" light is on. I took her out and put in 5 gallons of 93 octane to see if it was e-85 "gunk" possibly causing a restriction in my injectors (people say running pump gas will clean it out). I put in the 5 gallons of 93 octane, and now my ethanol gauge settled down and reads E27. I switched my car back to the 93 octane pump gas map and obviously the stoich point is different because I am running E27 since I didn't empty my tank. As I figure it, this should cause about a 7% lean condition - but even with my vacuum and unmetered intake issues fixed I am still seeing +12.5 on the long term and high short term (it's not switching around zero, its between 5 and 10 usually)
At a easy cruise my long term comes down to about 9.3%, and it switches around zero.
I know with explanation this sounds like it is SCREAMING a vacuum leak- but I can't find one with my smoke tester. Next I know I still have to pull up my tune but I don't use my windows PC often and I need to boot it up to run ECUFLASH.
Still waiting for the injector scaling numbers....
I loaded up ECUFLASH today, it's been a while since I even opened this program. This is what I was able to find related to fuel.
(I grabbed some MAF info too, since Air and fuel are one in the same)
I have a fuel pressure gauge right on my dash. It's the same as it's always been. Warm idle is about 38psi. When my 2nd pump turns on it shoots up to more than 60 (it's tough to watch but I think 75psi) I don't think this has anything to do with fuel pressure.
Can you let me know what your low and mid LTFT's where on E80? Those scalings do look a bit off.
Also, what was your AFR at WOT with E80?
P.S. Pay no attention to RightSaidFred.
I assume:
Low LTFT = idle
MID LTFT = easy cruise?
If so- I never documented the easy cruise one. I was just looking at my scan-tool in the driveway at idle. It was stuck at +12.5 and the short term was always positive.
My tank has E27 now according to my ethanol gauge (almost exactly half full from the gauge's perspective)
I am not set up to "log" the info so i have to actually look at my wideband gauge. this scares the heck out of me. I do plan on learning enough to get the car set up to be able to actually log and get the most out of the ECU even if I never physically grow a set of ***** to be able to make my own tuning adjustments by monitoring knock and such. My wideband is set up to show "lambda" so 1.0 = stoich, not 14.7. What should I have been seeing then? I would assume in old-school gas numbers it should have been around 12 right? (it was tuned by buschur) 12/14.7 = .81.
I use my wideband in lambda mode because I don't know how to change the stoich point. With E10 it should really read 14.1 for example.
If so- I never documented the easy cruise one. I was just looking at my scan-tool in the driveway at idle. It was stuck at +12.5 and the short term was always positive.
My tank has E27 now according to my ethanol gauge (almost exactly half full from the gauge's perspective)
I am not set up to "log" the info so i have to actually look at my wideband gauge. this scares the heck out of me. I do plan on learning enough to get the car set up to be able to actually log and get the most out of the ECU even if I never physically grow a set of ***** to be able to make my own tuning adjustments by monitoring knock and such. My wideband is set up to show "lambda" so 1.0 = stoich, not 14.7. What should I have been seeing then? I would assume in old-school gas numbers it should have been around 12 right? (it was tuned by buschur) 12/14.7 = .81.
I use my wideband in lambda mode because I don't know how to change the stoich point. With E10 it should really read 14.1 for example.
Stoich is 1 lambda on a gasoline afr gauge no matter what fuel.
You should get Evoscan and log low and mid LTFT. You could also get that via your scan gauge.
Yes, low is approx. idle and mid is approx cruise. STFT is current fuel trim adjustment and LTFT is stored fuel trim adjustment.
So basically STFT + LTFT = current adjustment. So it can be more than +/- 12.5 (cumulative) at any given time.
Stoich is 1 lambda on a gasoline afr gauge no matter what fuel.
You should get Evoscan and log low and mid LTFT. You could also get that via your scan gauge.
Yes, low is approx. idle and mid is approx cruise. STFT is current fuel trim adjustment and LTFT is stored fuel trim adjustment.
So basically STFT + LTFT = current adjustment. So it can be more than +/- 12.5 (cumulative) at any given time.
I understand the concept of lambda, what I mean is I can't change the ratio. I would love to be able to program my gauge to 14.1 with gas and 9.8 with E85. I read the instructions I don't think it has that ability (it's the autometer wideband with bosch lsu 4.2).
I have a tactrix cable, what else do I need to set the car up to be able to log with the wideband I have? I am nearly positive it provides a 5v signal output for this purpose.
I understand the concepts of STFT and LTFT. One of my hero's is a guy called "scanner danner" I pay for his premium channel on youtube. It is nothing but automotive diagnostic work. I use fueltrim to solve misfire issues all of the time. I actually have some really nice tools to do this kind of work. Problem is I need to develop the confidence in myself to get more into the deep tuning stuff. That's why I had buschur take care of this for me. (not to mention I'm not talented enough to build an engine by myself- yet)
When my 2nd pump turns on it shoots up to more than 60 (it's tough to watch but I think 75psi) I don't think this has anything to do with fuel pressure.
If it's not fuel pressure then what is it besides wrong and broken.
..........its likely that its one or both of the two issues that I mentioned before - The E85 tune is not good, and/or the injectors are badly gunked up. If the borescope is that versatile, go for it, although I think it might be easier to pull the injectors than it would be to remove the throttle body and then try to get a good view of the injector tips with the borescope.
Injectors removed:
They looked good to me, but I still mailed the to FIC for flow testing and cleaning.
Aug 24, 2017, 08:26 PM
