grabbem88

no cause I do not know how. But if my ve tables are leaner than stock. That would make it worse.
I tried putting 34 in flow rate and 31 and car went back to surging.

so I went back to my old tune and leaving it in open loop. At least my car runs well in open loop. Is there a target AFR in open loop?

ULTM8Z

I guess you could start with the current VE tables and then use your BLM's as a guide on how to adjust them. Basically for a given VE table cell, say for instance at 2500 rpm and 35 kPa map, the BLM is 116 at 2500 rpm and 35 kPa, then do the ratio 116/128 = .91. Then in the VE table corresponding that same cell, multiply the VE value by .91. BLM less than 128 indicates rich... so you're ratio-ing the VE cell down by that amount.

The opposite is true if your BLM is >128 (lean)... let's say 136. Then you'd do 136/128 = 1.06. In the VE table, multiply that cell by 1.06. You're ratio-ing it up to richen up that cell.

IF you can a good sampling of cells around the overall VE table, then you can kinda average in the remaining cells and get a pretty decent first pass at it. That is, you don't have ot get a BLM recorded in every single cell.

Couple of passes like this and you should converge on a decent VE table.

There are open loop tables, yes. One that's depending on coolant temp, and the other depending on manifold pressure. The code uses a formula to combine the two and produce the resultant commanded AFR.

grabbem88

That just went over my head lol

ULTM8Z

Well, I guess if your setup is more stable now with the proper injector offsets, then your tuners should know what to do with the VE tables if you can provide them with the datalogs....

That's the problem I was running into with incorrect injector offsets... the tune was just unstable no matter what I changed on VE, spark timing, accelrator enrich, power enrich, etc... I was chasing my tail and couldn't get it to converge. Once the injector offsets were corrected, the engine responded to changes more predictably.

BTW, what kind of O2 sensor is stock on a LT1? 3 wire? 4 wire? I notice you're running headers... I ran into grounding issues on my O2 sensor with headers, but mine was a 3 wire with heater, where the sensor grounded via the sensor body. A 4-wire has a dedicated ground wire for the sensor signal.

grabbem88

no tuner they all want $$$
i use 95 O2’s. They are heated did that 12yrs ago
so I looked at log watched the range on the short term BLM correct. I saw 140’s for a long stretch sometimes 160’s. So by your advice that’s 13-15% more fuel in those kpa’s

so when I moved flow rate from 30-34 that’s roughly 13% leaner. Here we go surge right there so if I add 13% of fuel in that area and lower my o2 swing to 400mv I might get somewhere??

ULTM8Z

Are you able to datalog with Tunerpro? Looks like you're using it to tune...

I have a VE tuning tool that I developed for the TPI stuff... but it's probably adaptable to a '93 LT1. If you're able to get Tunerpro to connect to your ECM for datalogging, I'll send you the ECM definition file I have for the DA3 ECM....

if you log with that and send me back the log file, I could take a crack at your VE tables, and see if that gets this thing to behave.

grabbem88

haven’t tried I just use scan9495

grabbem88

I just hope it’s not the opti or something stupid

Injuneer

This problem has been around for a while. Some other info you might find interesting :

https://www.camaroz28.com/forums/gen...roblem-888496/

https://www.camaroz28.com/forums/lt1...ks-lot-888512/

https://www.camaroz28.com/forums/lt1...e-look-888522/

https://www.camaroz28.com/forums/lt1...ed-out-888550/

Dyno results:

https://www.camaroz28.com/forums/lt1...r-dyno-888591/

grabbem88

not sure wtf this is about. But I’ll answer each one

first link solved. Harness got switched around simple mistake

2nd put stock 48mm back on fixed that problem

last was an ask because the tuner messed my tune up. Why would he put my injector flow rate to 27 and not 30lbs ??

the dyno is what it is so not sure what all my posts make it so interesting when half of it is me at the time had no clue what tuning or how to make/burn file/tune.

so now that I’m asking and giving the info the best I can with my abilities to receive advice/help. I’m not like some of these posters who ask then argue back because they didn’t like the answer they got... thanks for the help but I’m done

ULTM8Z

Faulty Ignition can definitely wreak havoc... I've unwittingly tuned around failing igntion coils, failing ignition control modules, etc, before. Then when the it outright failed and got replaced, the tune was way off.

With the (hopefully) correct injector offsets in place, we'll take a quick crack at the VE tables. Other than that, if it runs decent in open loop, you'll probably just have to do that.

grabbem88

that’s the thing open loop it ran good on old tune old offsets
now with old tune and new offsets flow rate set on 30 now to cut/cheat I put it on 31/34 both ways the car went back doing the same old stuff there is something for sure in the tables when it gets leaned as a whole the car runs like crap. You have my email

Injuneer

My point was NOT to ask you to explain or defend the previous posts.. I quoted ULTM8Z to get his attention, thinking he might find something that might relate to the current issue. And.... there are the data logs that I put a lot of time into, trying to help you out. Maybe he might see value in looking at those. He has a much broader outlook on the impacts of departing from the stock tuning than I ever had. Simply trying to help.

That's “wtf this is about”.

grabbem88

my bad!! Apologize being a grumpy old man..
it was a bad perception of me thinking I was getting shot at.. done

moving forward again. Some of those logs were from a Solomon tune. Which I am not using currently but do have the tune saved.

I don’t know if I should be using tuner 1 tuner 2 or 3 cause they are all different

ACE1252

The injector offsets were calculated by me using what I learned from Banish's DVD. That is my spreadsheet in the link for post #45. AdsoYo used them to help get his injectors dialed in. They are for FMS 30# "fat" redtops. I'm not sure if they will work right with the bosch orange tops. Sucks that most injector manufacturers don't put out calibration sheets. That's why I moved to the Ford injectors. They hand out the cal data.

https://www.camaroz28.com/forums/com...ts-lt1-770192/

I've yet to solve my tip in issue, but it's no where near the problem that the OP is having with his setup. I think my cam is 112 LSA and does run pretty decent.

Did LE spec out the cam?