djm_e22

iTrader: (2)

I am trying to tune my OBD1 Lt1 using tunercat. I noticed when in closed loop the stock O2 sensors were showing 108blms. I had trouble getting the car to move at all. Which I know being to rich will cause that as well but when I finally got my new wideband in it was actually showing I was running extremely lean. So I figured my new cam must not be working with the stock O2 sensors. So that is when I decided to go open loop only and I richened it up in that area and I had no problem getting the car moving.

First I tried to go Maf open loop. I would datalog my drive going up and down the road going through all gears making three or four trips with never turning off the car. But I am finding I make one trip I may be around 14.7:1 then another I am around 13.9:1. Making it very difficult to tune. So I figured maybe my cam is causing issues with my maf. So I decided to switch to speed density open loop. But in speed density open loop it pretty much does the same thing but maybe to a lesser degree.

I thought I heard your suppose to disable any fuel modifiers if tuning open loop. Maybe I missed some. Could you maybe give me a list of what I am suppose to do to tune in open loop whether it be maf or speed density? I thought I did everything I am suppose to but maybe I missed something.

Also does your afr change that much in maf or speed density when driving? It makes it very difficult to tune when driving down to point a and it shows around 14 then on the way back it shows around 13.

Please any help you can give is much appreciated.

WS Sick

I allways add a touch of timing and address the Volumetric efficency tables. It usually takes me quite a bit of work to nail it down, but a good scan program and good sensor input help quite a bit. One thing I am not sure about is there are initial start-up tables that when I play with them seem to do nothing, but they are there non the less...lol

djm_e22

iTrader: (2)

Yes I am messing with the ve tables now but it is hard to tune when I go down the road then come back and both trips show different AFR's. It was easy when it was obviously rich but now that I am getting it closer to the AFR I want I just cant seemed to get it to stay at that particular AFR. I know it won't be exactly the same each trip but I didn't think it would be that much different. Again in SD mode it seems to be to a lesser degree than maf mode.

gregrob

iTrader: (8)

You need to follow some basic tuning principles and get the car a lot closer to dialed in....

Set the idle RPM to something that allows the cam to be manageable... this helps tremendously, you can always change it later.

Tune IDLE... Work on the timing til it produces the most vacum, work on the VE table and MAF freq in those areas to get BLMS within +- 5%

Force the car into speed density mode and turn off fuel corrections and learning, then dial in the VE tables. Work it in all areas of steady state RPMs and a fixed load, and record the percentage AFR error between the MAF and your target (14.63:1)

Apply the percentage correction to those areas of the table, and smooth. Repeat til entire VE table is within +- 5% across the entire rev range and all engine loads.

Re enable MAF and 02s.... and assess any MAF error. Repeat process used on VE tables, on the MAF freq tables..

THEN AND ONLY THEN, Tune WOT....

To make it easy on yourself, zero the RPM correction to WOT table, and use the coolant temp modifier only. Then the RPM correction table can be used to smooth the AFR curve throughout the RPM range when you are close. Note that the RPM correction table uses EQ ratio. Get familiar with EQ ratio and what it means so you know what you are commanding when you put something into the tables.

During this entire process, use a conservative timing table... (stock or stock minus 2 degrees throughout the range comes to mind)

During WOT tuning leave the AFR slightly rich, say 12.4-12.6:1

When that is settled start adding timing to find MBT, reading the plugs, the absensce of knock, or a combination of all those. Whatever your method is....

During this time you will have to watch for / address false knock.

When you feel you have the ideal timing curve for your combo. Go back to AFR, you may find the AFR is now leaner, due to more efficient combustion process because of the increased / proper timing.

If AFR is not what you desire, adjust.

Also as with any tune, you need to be sure you are receiving accurate data. Good 02's, TPS, MAF is clean / functional, no vacum leaks, no exhaust leaks, no fluid leaks, engine coolant temp is under control...

You also need to make sure any modifier tables to AFR and timing (coolant temp and IAT comes to mind) are zeroed during the tuning process, in the range in which the engine is running...

In short, you dont need an OLSD tune. You are trying to use an OLSD tune to over simplify it and make up for an incomplete tune. Just start with the basics and dial it in. It takes time.

Wicked94Z

iTrader: (26)

the above sounds pretty damn good

gregrob

iTrader: (8)

Also you should make sure you have the proper IFR and Offset tables in there for your injectors.

05HD

Every experienced tuner has their own way of going about things but, what it comes down to is you have to know what needs to be changed when. It is very important to start out with good injector data in the correct tables. It is also very important to start out without any mechanical problems in the car.

From there, I will use different approaches based on how far the combo I'm tuning is from stock or how far it is from a tune I have done in the past.

I usually prefer to use open loop only, unless the car still has a cat on it. It is also much more consistent to disable all of the PE adders permanently as well, once again, as long as the cat is in the dumpster where it belongs. All of that junk is purely for emissions.

Speed density vs. MAF is personal preference and or application dictated. I like speed density, KISS principle.

djm_e22

iTrader: (2)

First thanks for both of you helping me.

I pretty much got the idle working great. I am kind of only temporarily doing open loop. If what I try doesn't work I will stay open loop. Basically I tried closed loop and the blms were split. So I made sure to get all the idle air to not be going into the main plenum which seem to make things a little better but again still got blm splits sometimes at idle but mainly cruising. So I decided to check my plugs on the lean side(passenger bank) and all the plugs were a little rich with all them be consistent with each other. Which tells me there isn't really a single cylinder to blame on the the stock O2 showing lean. So why would it be giving it more fuel.

So getting frustated I put all the ve and maf tables back to normal to start over and just like before it started off super rich with 108's both sides. Knowing that I am just going to get split blms again as I start to try to tune it I decided to hold off till I get my new innovate brand wideband in. Sure enough even though the computer's O2 were showing 108's my wideband was showing me with an afr reading around 16 and 17.

So I figured I'd try to tune open loop for now using the wideband on the driver side bank and when I got a basic tune down I will move the wideband to the passenger side bank and see if the afr's are pretty consistent with the driver side bank. If they are then my engine/cam combo I am thinking is causing my O2's to not work properly.

http://www.racetronix.biz/itemdesc.a...1D030x&eq=&Tp=
The above site ^^^ are the injectors I am using. I changed the IFR in the constant table to 42.29(I just noticed I actually had 42.15, not sure if that can cause all these issues. I will change that) but I am not sure what pressure they are rated at. For some reason I had the idea that they were rated at our stock pressure of 43.5. I won't lie the injector offset vs battery voltage I havn't touched. I am not sure how to adjust that correctly. It has to do with the opening and closing of the injector, right?


I have tried to disable all the fuel modifiers. I pretty much upped the temp to where they can't enable themselves unless I am at 150* C. Is that the correct way to disable them? These are what I have disabled off the top of my head. All in the constant table. DFCO, EGR(no longer hooked up), Canister Purge, CAT, CARS, Air Pump(no longer hooked up)

Is there anything else I am missing with other tables to properly tune in open loop?

By the way I have noticed that when I first start driving on the first run my iat is around 103 probably from letting the car sit for 5 minutes or so before I start driving then it will slowly start to cool down. I wonder if that could cause my AFR inconsistency. Maybe I should move the iat closer to where my cold air filter is at. Right now it is right by the throttle body.

gregrob

iTrader: (8)

Did you receive injector offset info with the injectors? That needs updated as well.

djm_e22

iTrader: (2)

I got those injectors a few years back when I was OBD 2 and I had Moe Bailey do my tune on my old 306cc setup. Never thought I'd be tuning myself. I'll try to get a hold of racetronix and see if they can get me that info.

WS Sick

I never thought of getting the VE tables nailed in SD and then going from there, thanks for the fresh thinking Gregrob. I know I spent hours upon hours of adjusting, driving and monitoring, adjusting etc. I do know that a smooth VE table (transition wise) is a must, if its too lumpy and jumpy looking it runs like crap.

djm_e22

iTrader: (2)

I just got them but there must be some kind of converting I need to do. Here is what I got from racetronix. I assume "ms" is for milliseconds and "usec" is for seconds. Not sure what the "u" is for in usec. I'm thinking I just need to convert it into seconds?

For example
Racetronix - voltage/time offset(ms) @ 6v/3.972(ms)
Racetronix - voltage/time offset(ms) @ 14v/0.688(ms)

but tunercat looks like this
Tunercat - vdc/offset(usec) @ 6v/5585(usec)
Tunercat - vdc/offset(usec) @ 14v/275(usec)

Since I am messing with these tables I guess I should go ahead and ask is there any reason that I would need to change anything in the "low pulse width injector offset adder vs BPW"?

05HD

usec= microseconds. 1000 usec= 1 msec

gregrob

iTrader: (8)

For idle and driveability reasons yes. Plug in all the info racetronix gives you.