Texas_Ace

I am confused then, how can i see the stock fuel trims? My OBD software doesn't show those that i know of. at least not in a way that makes it easy to tell what they are. As i drive it i can see what the fuel is doing at a given time but i can just view the whole fuel trim. Is that even possible?

Yeah, mine doesn't do that. If i press th gas it goes lean, unless i hold it at the same spot for a little bit then it comes back down the 14.7 ish. When i let off the gas is goes lean for a split second then goes rich in open loop. but for normal driving it is virtually always lean, ~15.X:1 or higher most of the time.

20 degrees being the stock timing advance at WOT and what i want the ECU to think it is still giving the engine once i add in the retard with the URD.

But i agree lets leave the timing for later, that is a lot easier.

Speedy

I have the OBDII BR-3 and here's what mine shows. You can see the fuel trims clearly. You want the two values to add up as close to zero as you can get.

Texas_Ace

AH, that is what you are talking about!

I had seen those but turned there reporting off as the more i have reporting the slower it reports overall.

I need to turn those back on and watch them. As said this is the first time tuning with a piggy back and as i am finding out it is quite differnt then a stand alone. Stand alone you just enter how much fuel you want and what timing, piggy back you have to do lots of math lol.

So what is the differnce between the short term and long term trims?

Speedy

Short term is what the ECU will do immediately. Long term is the AVG over a longer period. Short term should change pretty quickly when you're tuning. Long term may take a week or so to change to be a valid variable in your tuning.

If you see a huge amount of negative value in short term then you're dumping too much fuel in. If you see a huge positive number then you're not putting enough fuel in. These numbers tell you how much fuel the stock ECU is adding or subtracting from the base map in the ECU.

Texas_Ace

Ok, this makes more sense. So in the case of that screenshot above you need to take some fuel out it would look like? or like Ian said above are you supposed to add the vaules together first? in which case you need to add fuel?

Speedy

You add the two values together to get your total ECU adjustment trim. In the example screen shot I posted

2.3 - 1.6 = 0.7 (very close to 0)

So I leave it alone. Adding fuel made it go too rich, and removing fuel made it go to lean. The numbers also won't stay the same, they're constantly changing. You just want the over all average of all those numbers to come as close to zero as you can. It'll never be perfect.

The granularity of the piggy back is part of the issue. It needs 1mili second minimum of time for the injector to respond. Sometimes that's too much, sometimes that too little in terms of fuel trims to get them to equal zero. I believe the U-Tune AIC guide says if you get them under 10 you're doing really good, under 5 is excellent, but double check me on that quote.

Joe's Toy

Well I have to say I'm both blown away and scared by all the knowledge being passed around. It makes me wonder if I'll be able to tune when I get a SC. Good read guys!

Ian Rogers

i have mine at or below 6 right now, I have found that the URD 7th injector is Huge. This makes it hard to adjust for fuel trims under about 10, if i put the smallest amount in 1.1 milliseconds i run to rich. You will find that some times you get close enough for the ecu to adjust. If you are going to be adding the 2.2" pulley i would wait to do any tuning until that is on, other wise you get to tune again once you change the pulley. I am working on meth injection and once i do that i am going to re-tune my winter map for about 2 hr with my girl friend, then i will have to re-tune my towing map. I pull my fj40 some times and have found that i get in to different load cells and need more timing pulled to stop ping.

Ian Rogers

I have had great results running the Scangauge II Because it is ALWAYS in the truck and hooked up. This lets me know if any thing need adjustment no matter where i am. I would suggest every one get one and have it in your truck. I mounted mine above the steering wheel in the line of sight of the gauges. It also lets you clear and check a check engine light any where.

Speedy

Wow, I did pretty good on mine then. I'm avg about 2 or 3 or less on trims the last time I checked.

Speedy

Yep, great tool. I use mine to monitor gas mileage in my daily driver Honda Accord. Before the SGII I was getting 28MPG, now I'm around 34MPG with just adjusting my driving habits.

Ian Rogers

I dont know if the headers, cat back, AL flywheel, have made a difference in the amount of time i spend in each cell making if harder to get the tune spot on. But i feel happy, and the truck runs good. I have always felt it was better to be rich then lean and have reflected that in my tuning. But good job speedy.

Speedy

I'm sure that other stuff makes it harder, you also have a 500RPM gap in cells, so it's not the most granular.

I was a little bummed I couldn't get it closer to 1 personally, but the truck runs awesome so I just accepted where it is.

Texas_Ace

Ok, first off i put another ~50miles on it today. And i have learned a lot. I think that the ECU being in learning mode is what is cauing the lean out in closed loop above 14.7.

I noticed that it is ALWAYS "hunting" for that 14.7. Even when at idle it goes from 14.4 - 15.1 or so. The more i am driving it though the less it is hunting. By the end of the trip today just driving along it was actually pretty close to 14.7 in closed loop and the open loop is still looking good on the AFR's anyways. Need to look at the trims though.

That is what i thought, i always like to duble check things i am not 100% sure of though. I like to get things done and i sure as heck ain't a perfectionest but i do like to do it right. It just might not look pretty or be perfect lol.

Indeed, if it was not for the help i am getting here i know i would be near as far as i am. Though once you know the basics it is really pretty simple. Most of my problems came from mixing up the maps and the learning mode on the ECU (at least that is what i think it is).

I don't plan on doing much more tuning right now until i get the 2.2 pulley installed. I also ordered the O2 calibrator from URD today/ So i will just drive it as is for the next few days and see if my AFRs keep getting more consistant. If so then i am good, if not then i think i will get another O2 sensor and hope that fixes it. I know that usually they last right at 100K miles and it has 128k on it now.

When i get rich i might have to get one of those, that sounds quite nice!

But then you also spent 30 hours on installing gauges, how come i am not surprised that you got it down to 2-3? lol

Have you put it on the dyno? any numbers?

OH NO! it was off by a point or 2 what ever will he do! lol

Ian Rogers

I am waiting to get on the dino, until i have the meth and have re-tuned my truck. the last time it was on the dino was at dough thourly shop when they test fit the headers and cat back i was N/A at the time. The Scangauge II waas about $130 and i feel it was worth every penny. I wish the maps were in 250 rpm's rather than the 500 that they are.

Speedy

Off topic but how are those headers holding up? I almost bought a set, but decided to pass when we found out they weren't stainless.

Texas_Ace

Would like to know the same thing as i have the same headers. I know so far mine are working perfect except for the leak that was the exahust shops fault.

Texas_Ace

Ok, another update. I have put some more miles on it today and i am now 95% sure that my leanout problems are being caused by the ECU being in learning mode. BUT from the way i read other people tuning stoies they never had this problem.

I wounder why i am?

Anyways my AFR's in closed loop are now getting more and more steady at 14.5 - 15 also not getting near as much lean out when i give it a little gas in closed loop.

My O2 calabrator should be in later this week so once i get that i will install the 2.2 and start really tuning it.

Speedy/Ian, if you would not mind i would love to get a copy of your maps. Should give me a good base to start tuning and will let me see what a proper tune looks like.

My e-mail is Texas_Ace_AA at yahoo.com That would be great.

Ian Rogers

The headers are holding up great, i have had them on since sep 07. Great mod especially because they were free. I have no dis-coloration. There was a small leak on the pass side collector the bolt loosened. I tightened it up and have not touched them since oct- 07

I can send you both of my maps, winter and summer. I just have to get the car laptop out of the car.

Texas_Ace

Those maps would be great, this weekend i hope to start really tuning it. but i will have to reset the ECU when i install the O2 calabratior so i might have to wait a little bit.

Ok so today i went ahead and installed fuel pump. Overall quite easy, took me about 1.5 hours.

Here are some pictures:






After i got it all back together i started it up and drove it a little and noticed that it is running noticeably richer now. So at least i know that it really does flow a lot more fuel. My AFR's dropped to 13.x though the ECU started correcting it pretty quick. even now it is still running quite rich.

I also went by the exahust shop to have the leak fixed and a high-flow cat installed, the good news is that i got the cat installed. The bad is that they were not able to fix the leak today. The head guy was not there and the underlings could not figure out how to fix it.

So got to go back tomorrow to get tha fixed again.

In other news as expected i threw a code after the cat was installed. So i am going to try the home made O2 simulator that Goat pointed out to me. I already have the parts just need to wire them in.

Plan to do that tomorrow. I PM'ed the guy that did this first and he says that 10,000 miles l;ater he is running fine with no codes. So here is hoping that $3 at radio shack can save me the $60 from URD. Will report back on how it works.