85 IROC TPI 1227730 conversion from 1226870

[EagleMark]

Well if it's from cardone it's a 50/50 shot it'll work. But I'm surprised Autozone even has them listed? It's probably a mistake like when they were the only one that had a LT1 starter solinoid... it was a regular chevy small block...

[Tunedperformance]

I see that you have also had some good luck with there remanufacturing as well.

[EagleMark]

Yeah so much for USA quality products... last 5 years I've had better luck with cheap chinese knockoffs...

[zaut]

I am not sure. The first one I ordered was for a 86 5.7l F car. It was supposed to take 21 days, but it came in the next day. I didn't ask when I ordered the AUJP memcal assuming the same situation. It's been about three or four days now.

[zaut]

I am getting a good grip on scanning and summarizing my BLM vs VE% tables. Does anyone know what the scale or relationship of BLM number to the VE%. I understand under 128 is rich which means I need to lower the VE%. I've tried adjusting VE% based on percent change that the BLM is from 128. Assuming the BLM is linear, my process should yeild close results but I keep overshooting.

[zaut]

I'm getting closer and closer to getting my fuel correct. I am running into a couple issues that are confusing. It seems that in general, when I adjust a VE% in the tables, the outcome is as expected. Lower the number, get higher BLM and vice versa. However on some occasions, the opposite happens, it seems to only happen when I am trying to go from rich to lean. In certain areas, I lower the VE% and the BLM goes down more. Does anyone have an explanation on this? Also, I know 128 is ideal, but what is acceptable? When should I stop? Tunerpro changes the font color from blue to red at like 132 and 124. Is that my target, to get everything within 124 to 132 or should I be shooting for a tighter grouping?

[EagleMark]

The changing color is just how the alarm is set in TunerPro. 124 to 132 is fine. Even if you got a perfect 128 everywhere when weather changes so would it!

The areas your having trouble in may be from other factor. When I tune VE from BLM I turn off PE, DFCO, EGR. Lean Cruise etc... everything that I can get my hands on to turn off. Because everything is an adjustment based off VE table! My only exception is AE because it is just horrible to drive without AE and would probably result in faulty data. When done with VE I turn stuff back on.

You can always make a note in TunerPro XDF by right click, edit XDF parameter info and add a + or = or- or note after the title to remind you what you have on, off, changed etc...
Always start data log after warmed up and a little drive. Then log, take a peak at BLM history table and try to fill in as many spaces as possible. It's impossible to fill in all.

Another thing that may be affecting cells your having issues with is if they are on edge of recorded BLM data and you have not smoothed cells outside that. Remember the VE cell is interpolated to 4 surrounding cells.

[zaut]

Thanks, I was thinking that the surrounding cells were causing the issue. The anomaly was mostly occurring when surrounding cells were on the verge of being too rich. If 124 to 132 is fine, then I am there. I have been shooting for 126 to 130 and getting almost everything in that range. Being an OCD electrical engineer, I was going for perfect. I use Excel with pivot tables to see the BLM numbers. I can summarize the whole range of RPM vs MAP vs BLM in minutes that way. I use averages and the grouping function to get there. With respect to scanning, I have everything off except PE. I see how it affects my BLM at WOT. I will do a few more scans with PE off and if good, move onto the spark tables. Should I do the same and leave everything off to get the timing correct? My only issue with doing the spark is that I am still waiting for the correct MEMCAL for the car/knock sensor. Should I worry about not sensing the knock or is that the true feedback for having the correct advance?

[EagleMark]

Being an OCD electrical engineer, I was going for perfect.

PE is also a calculation based off VE.

Once VE tables are done and smoothed turn on everything to work on spark, so spark has correct amount of fuel to work with in all situations. I would wait and use the knock sensor as a tool.

Lots of guys use an LT1 timing table for base, but have to be careful how you implement it as a starting point as to your ECM spark bias settings compared to LT1 bin. It's a very smooth table compared to other bins. You'll see big changes from stock timing to performance timing table you end up with.

[zaut]

Sorry for not getting back quickly. I had to start a yard project. I'll look at the LT1 spark table.

[zaut]

Now that I have my fuel looking pretty good, I need to get my knock sensing working. Well, as Mark predicted, Autozone (Cardon) is not going to be able to get me the AUJP MEMCAL that I need. So I revisited using the ESC module and Knock sensor from a 350 engine. I did some studying of the 1227730 EMC schematics from the Ludis website. I believe the ESC module will work by examining the schematics. The ESC input is B8. This input is in parallel with the output of the MEMCAL knock filter on CAL 32 (pin 32 of the MEMCAL). I also found out from Thirdgen that the EMC is looking for about 3.9K ohm to ground on F9, the knock sensor input to the ECM. If it does not see that resistance, it sets code 43. So what I did was cut the knock filter off of my MEMCAL and added a 4K ohm resistor from CAL 29 to CAL 31. CAL 31 is ground. This simulates the knock sensor and the 100 ohm resistor that is in series with the knock filter. Because of bad weather I couldn’t test drive the car, but I do not get a code 43. What I don’t know is what is to be expected in knock count data. With the car running in the garage, I got one count in about ten minutes of running. I tried hitting the block with a hammer but there is no clear shot at it without jacking the car. So my question is, what should I be seeing with respect to knock counts?

[1project2many]

Being an OCD electrical engineer, I was going for perfect.

Wanted to mention OE tuning allows a window of +/- 10 on BLM with INT falling with a much smaller window. The fueling code is not accurate enough to resolve it better.

Knock counts will either be reset to zero when the ecm is initialized or will begin at whatever random value is found in dynamic RAM on startup. The actual knock indication is apparent as delta counts. Occasionally there may be random, sudden, large changes in knock count which may be a software issue although generally these won't affect performance. I have seen this mainly in $58 (SyTy and turbo Sunbird) although it's not exclusive. If this happens it's easy to resolve the issue. For example, a change from 10 to 50 knock counts over one data frame at idle with no additional load in an otherwise well running engine is not likely to be knock. If you can't get to the engine to tap it you can always advance timing enough to make slight knock. Usually 2-5 degrees additional under light load for one or two tests won't hurt anything. You might also try enabling high octane spark test if it's available in code. That test simply advances timing and additional 2-5 degrees during acceleration to check for knock and if none is found, timing is taken from the high octane spark tables.

HTH

[zaut]

I am going to jack the car up and tap the block from underneath. It’s not that difficult to do. More than anything I was interested in knowing what or how often I should get knock counts. If the engine isn’t knocking; I assume I should get zero counts. I’ll do the recommended procedure in the service manual. It says to run the engine at 1500 RPM and tap near the sensor. You should get a RPM drop when you tap. I'll also watch for knock count changes.

[EagleMark]

As long as the engine is running and your recording data the knocks should show up! The 1500 RPM sounds like a trick to notice without data.

Also found this and has some great info on $8D and thought it would help you.
http://www.edgesz28.com/edgesz28/sup.../super8ecu.htm

[zaut]

I followed the recommended procedure to test the knock sensor. At first the ECS did not work. I was getting counts but no timing changes. I discovered in the BIN that the system will not retard timing unless I am going over 2 MPH. I fixed that and the system works. I tapped on the block and got some spark timing retard along with an increase in knock counts. If I unplug the ESC module, knock counts start climbing like crazy and I get as much timing retard as available in the tables. I plug the ESC back in, and timing goes back to normal. I loaded the LT1 spark tables in my BIN. On a test drive under heavy acceleration up a hill I was able to induce some knock. The sensor picked it up and retarded the spark about 5 degrees. My conclusion is that what I did to the MEMCAL and using B8 as the ESC input works fine. I would suggest or ask how to make this change available somewhere under web site. Maybe it should go in the fuel injection write-up articles.