Starting to tune my fuel tables tomorrow.

[joegreen]

I have been reading about what to do to get good data so i can tune my fuel tables. I have a few questions.
1. I am using the AFBW bin. Is this an ok bin to use or is their a better starting bin for a 5.7 with a th400?
2. what is VE as % (FL2) and do i need to tune it or just VE as % (FL1)?
3. I am going to disable PE and work from a little throttle to a lot to try and fill all the blm areas i can. Is their anything else i should disable or any special way i should drive in order to get the best data?
4. The VE table only goes to 3200 rpm so how do i tune for 3200-4500 rpm?
5.I am using the VE correction table for tunerpro. I noticed it only goes to 1800 rpm. Is that all the table can calculate for is 400-1800 rpm? How do i get calculated VE tables for 1900-3200?

Thanks guys i am just trying to make sure i don't mess anything up.

[joegreen]

I was doing some reading and saw some people add the ve1 and the ve2 tables together. From what i gather the computer adds the ve1 and ve2 numbers together all the time anyway so having one table would make it easier for me to modify. Is that an ok thing to do? If i do add them together do i add the ve1 to the ve2 or the ve2 to the ve1? Also the ve1 only goes to 3200 rpm so how would the ve2 get added to it at higher rpm's?

[joegreen]

Here is my first datalog with pe disabled. When looking at the blm history should i look at the history average?

[joegreen]

Found this awesome post by eaglemark. http://www.gearhead-efi.com/Fuel-Injection/showthread.php?1895-Adjusting-VE-Fueling-tables-with-BLM-data-Tutorial!

[CFI Z51]

That thread should have answered most of your questions ..
Log looks ok other the being way rich everywhere ..
As to a better/different bin i think i have an ASDU starter bin for use with the th400 if your interested?

[joegreen]

That did answer alot of questions. i started changing my ve table and now my blm's are getting closer to 128. like 122-130

[joegreen]

So what do i do about the blm's that dont get filled in? Also after the ve is set what is the next step?

[sturgillbd]

The VE table will follow a trend or a curve. You can interpolate between points and get it close. Look at the table in graph view. It is basically impossible to fill in all of the cells with datalogged BLM data. After you get the ve table close, start playing with timing. There are a few timing tables posted on the forum that are good starting points to build your timing table with. http://www.gearhead-efi.com/Fuel-Injection/showthread.php?2540-Performance-Timing-Table-Chevy-5-7-Liter-TBI-ECM-1227747. The timing table will have to be tweaked according to your particular vehicle. Does your engine have TBI cylinder heads or are they the original carburetor heads like the old 882 castings? Just watch for knock counts when datalogging.

HTH
Brian

[joegreen]

well after getting my stuck thermostat fixed i started to tune the ve table again. When the thermostat was stuck the ecm temp sensor said it was 170 degrees f. I thought that would be a high enough temp to get some data but i was wrong. I cant believe how much different the blm's are at around 200f. Tuning the blm to 128 at 170 degrees f made me run in the 140 blm at 200f. Anyway i am running the original carb heads. 8.5:1 compression and the heads are prone to cracking. Why wouldn't the stock timing table be a good start? Did gm limit performance or something? Thanks again for the serial cable, it works like a charm.

[joegreen]

When do i call my ve table good enough when i cant possibly get blm's for all the data points?

[fastacton]

When you're happy with it. You can guesstimate some of the points that you're missing, but if you can't get them, you probably don't spend much time in that part of the table, so not a lot of tuning will be needed there. You'll have to go back to the VE tables after you do timing tuning.

[joegreen]

So the new problem is if i get into the throttle with not alot of rpms's maybe 1200-1500 going up a steep hill i get a code 43 and 45. Both of these codes go away when i shut the vehicle off and then restart it. I always set the codes on the same spot on my data logging run. The problem is is when the code is set it changes my blm's. I am not super concerned about code 45 but code 43 concerns me. Is their anything i can test for? So when i noticed these codes setting the other day i checked under the truck and saw that the knock sensor wire was unplugged. I forgot to plug it back in when i was changing my front brake hoses. I thought plugging that in would solve the problem. It did not. Do you think i might have a bad knock sensor? Also even though my ve table is getting good my truck does not have alot of power. I can hold the brakes and put the accelerator to the ground and the engine revs up a little but that's it. Today was the first day of datalogging with the knock sensor plugged back in and i noticed the truck has less power and that when the engine is cold if i stab the gas pedal it pops through the throttle body. It never backfired through the intake when the knock sensor was unplugged. If i tap the knock sensor or the engine block should i see knock counts on tuner pro?

[sturgillbd]

43 can be set if no knock counts are detected or knock is detected for more than 5 seconds and the ecm has pulled all of the timing it can.

43 The ECM did not detect a knock signal during near wide open throttle operation with coolant temperature above 194° F or the knock signal was present for 5 seconds or more during normal engine operation.

Do you hear any ping or a rattle when this code is set? You may need to pull some timing or add some timing at that area of the map signal and rpms. Do you have the transmission kickdown switch installed on your truck and adjusted properly or are you using the ecm to control kickdown? High map/load and low RPMs can be a surefire way to get knock. You will have to look at your log to see if the knock counts are going up to see if it is too little or too much timing.

Brian

[joegreen]

i do not hear anything abnormal. Also i do not get any knock counts on tuner pro. Can i test the knock sensor by tapping it?

[sturgillbd]

yes. Just tap on block with a wrench and it should register knock counts

[lionelhutz]

You should see a bunch of knock counts from starting it too.

[joegreen]

i get zero knock counts all of the time. I will start by knocking on the engine and the sensor. If that does not work i will test the wire going to the sensor. I will ohm the sensor and i will check if its putting out an ac voltage when tapped.

[Kitch]

I routinely get about 1000 knock counts shown in TunerPro just starting my engine.

[lionelhutz]

Ya, it's not working right now.

[joegreen]

so here is where i am at. I think their is a problem with the electronic spark control module. The module gets 12v with the key on. Their is a good ground from the module pin d to engine. Their is continuity between the module pin c and pin b7 on the ecm and their is continuity between the module pin e and the other end of the wire where it plugs into the knock sensor. The problem is is the escm is not giving out 5+ volts on pin e that goes to the knock sensor. Can i call that a bad escm?

[joegreen]

Also when i take my dvom and check ohms between the center pin of the knock sensor and the body of the knock sensor the dvom shows a constant open.

[lionelhutz]

That doesn't sound right.

[joegreen]

I just want to verify that the blue wire coming out of the esc module going to the knock sensor is supposed to have at least 5 volts on it. Also i want to verify that i should get 100k ohms between the center pin of the clock sensor and the engine block.

[fastacton]

The ESC gets a full 12 volts, I've never measured the wire going to the knock sensor to see what voltage it gets, however. Normally 100k is correct for the knock sensor, but there were a good number of knock sensors used and I believe that most manual transmission versions were 4k. If you're showing no resistance or infinite, it is definitely bad (assuming that your meter is working properly).

[lionelhutz]

I have never measured the wire from an ESC to the knock sensor either so can't help you there. Considering the circuit, I wouldn't have expected that wire to have a voltage on it.

The knock sensor should measure 4k ohms or 100k ohms though. Offhand, I just don't know which one your EFI system should use.

[joegreen]

Ok so i do need a new knock sensor and esc. I found this list of knock sensord and esc modules. ESC Module Knock Sensor Motor
----------------------------------------
16052391 ....10456287 ....5.0L V8
16052401 ....10456288 ....5.7L V8
16128261 ....10456288 ....5.7L V8
16065711 ....10456288 ....4.3L V6 and 5.7L V8
16128251 ....10456288 ....4.3L V6 and 5.7L V8
16131171 ....10456288 ....7.4L V8 I never saw one on a Big Block?

My current esc module is the 16052401. I found some new old stock modules on ebay. I was looking at a 16128251. Would that esc module work ok with the 7747 with a 5.7 v8. I know it says it will work i just want to be sure because it also mentions its for a 4.3. Also if i get a knock sensor at the junk yard i know to test it for 100k ohms but what ac voltage should i be getting out when i tap the block or the sensor? Thanks

[joegreen]

I managed to score the metal bracket that bolts to the intake manifold that holds the map sensor and the esc module and the other vacuum thing with all three of those parts still attached for $17 shipped. Anyway i put in the new used esc module and i still dont have 5v going to the knock sensor. Can someone test their blue wire going to the knock sensor on a known good system and let me know if there is any voltage. Thanks

[joegreen]

Can someone with a working knock system test their blue wire going to the knock sensor and let me know if it reads any voltage? Thanks

[fastacton]

Just a few millivolts with key on engine off. Don't have a throttle body installed at the moment, so can't check engine on.

[joegreen]

Thanks. I bought a new knock sensor off of amazon. It's supposed to arrive Saturday. I hope that's all I need to get my knock sensor circuit working.