ChevyTycoon

iTrader: (1)

Merry Christmas and Happy Holidays folks!

I've been a lurker for over a year now (and read pert-near 3 years worth of archives in that time) since I've swapped an 86 305, MAFTPI (cold start inj.), '165 ECM and 700R into a 72 GMC pickup.

I have a full logging/programming setup via Moates, eraser and writer, TunerPro RTv5 and dozens of 27C EPROMs begging for use.

I've gone through about 30 different combo's and have finally realized that I’ve reached my knowledge limit so I’m reaching out to the experts. I've gone through the definitive 32b tuning guide, as well as SD articles in the stickies as well but still looking for this one thing....

My problem and my question: I (have) continuously hit knock at roughly 3000-3400 RPM on slight inclines on anything over 1/2 throttle. In data logging, I plainly see spark advance regularly hitting 50 Degrees (Spark Adv relative to TDC) even though the Spark Advance vs. RPM vs. Load table (Tuner Pro RT v5) has a max value of 21.15. My initial SA is 10.55 and equals my mechanical distributor setting. Obviously, I hit knock (and throw a code) at anything over 43 degrees, so that's the problem.

My question is, from where does the "extra" timing come? My understanding is that, in TP, the SA v RPM v Load table is WYSIWYG and if that is 'maxed' out 21.15 how is the engine getting to 43+?

As a troubleshooting step, I've set the WOT SA to zero's; Hwy Mode SA set to zero as well. Still 20 extra degree's being logged....

Anyway, if this is a topic that has been covered in the years of archives, I apology for the redundancy but thank y'all for your patience. I eagerly await knowledge.

RBob

iTrader: (1)

There is a forced knock test in the code. Maybe that is adding the SA. This forced knock is to test the ESC system. You mentioned that it is throwing a code? 43 perhaps.

RBob.

ChevyTycoon

iTrader: (1)

RBob: I do receive 1 knock count upon initial startup - and the knock count stays at 1 for the entire time. But I have not ever recorded knock counts higher than 1.

For a better description, I should say that up to a certain point, my SA v. RPM v. Load table = Spark Adv Rel to TDC but past that point its as if additional advance is "magically" added somewhere. When this occurs my SA v. RPM v. Load table < Spark Adv Rel to TDC by up to 20+ degrees.

For a newbie like me, its almost as if there is an additional table somewhere that is referenced but is just not available in TunerPro. And with the SA In WOT vs. RPM set to zero's, I just don't know where this additional "ghost" setting would be.

Exact Code is 43

ChevyTycoon

iTrader: (1)

Still looking for any input from anyone with this same experience, but over the Christmas break I had time to review everything again.
I did find one major anomaly: my base (initial timing) mechanical had moved to 4 deg retarded although my programming had 10.55. While I went thru the effort of resetting base timing to 8(ish) deg, I also experimented by changing the initial spark advance scalar from zero to 10. This definitely altered my SA Rel. to TDC readings and I still encountered knocking even with a low SA table – but it didn’t solve anything.

In the meantime, I’ve sort of “cheated” in order to eliminate the knocking by setting the Max Spark Advance to 38 deg…..
Either way, by the end of my experimenting, I still have the same issue: I have still yet to determine where this extra “ghost” spark advance is coming from.

To hopefully stimulate some conversation, here is a screen shot from the dashboard of my issue. As you can see:
· SA Rel. to TDC number = 42.19
· Spark Adv Rel to Ref Pulse = 34.80
· initial SA setting = 7.38 deg
· SA in WOT ranges from 0.00 to 5.98
· SA Table has a cell value of 23.91. (Data Tracing enabled which correlates to the cell being used)

So, how do I get 42.19 as total timing?

EagleMark

When EGR is enabled it adds advance?

ChevyTycoon

iTrader: (1)

I never thought of that, but I can try it out. But for the record EGR is not on the vehicle (being a 1972) and I have the EGR diagnostic flag not set.

The only other items or the scalars but they are set at 1.95% currently and it stands to reason, then, that "EGR timing" would be added at low RPM's as well.

But I'll try it so thanks for the suggestion

EagleMark

Just because you turned off the flag does not meen you disbled EGR!

There's your sign (spark)!

RBob

iTrader: (1)

ChevyTycoon, everything points to the forced knock test failing. That is where the additional SA is from. And since the ECM isn't seeing any knock, keeps adding SA to force it.

By which you have posted that it is knocking (can hear it). Then the ECM throws code 43, which means that the ESC system isn't working. IOW, the ECM tried to force knock, which it did, but it isn't being reported to the ECM, so the ESC system is bad.

Either the plug fell off the knock sensor, or it or the ESC module is bad.

RBob.

RBob

iTrader: (1)

Just to add, the electric fan switch and knock sensor use the same connector, and are close to each other. You may have the fan switch wire connected to the knock sensor, which will also cause the forced knock test to fail.

The wire for the knock sensor is dark blue.

RBob.

EagleMark

Since it's a conversion, and I would beleive RBob over my idea, I wonder where the knock sensor was placed as well as wirieng mentioned? And if it was correct knock sensor for ECM as well? I have seen conversions mount knock sensor on... well a lot of places but if they are not in block water jacket they are not working properly.

Back to EGR, my thought was not without info, here is a good read from Detroit engeneer on EGR. You'll notice he mentions 20 degrees could be added with EGR... same amount he is finding added?

http://www.gearhead-efi.com/Fuel-Inj...-does-not-hurt!

ChevyTycoon

iTrader: (1)

Thanks Rbob! Interesting. Would this bad ESC module be an intermittent issue? There are times that I can drive 20+ minutes w/out encountering my issue. Living in Denver, if I don't drive up into the foothills/mountains, I may never encounter my "ghost advance". Additionally, when I do encounter my knocking, the ECM properly retards timing (but I often throw the SES light). But after 6 months of frustration, I'm willing to try anything.

As for the wiring option you mention, and as Eagle stated, my wiring harness is a custom unit from TPI Specialties. The ESC is mounted up on the firewall of the truck (a 1972 GMC) and properly wired. I'll double-check the connection at the knock sensor - a good idea! (which is located on the passenger side of the block into the water jacket as it should be)

Another interesting item I encountered today: I have set the maximum spark advance scalar to 36.73 degrees (lowered it some more from 38). This definitely affects the SA Rel. to Ref Pulses as I clearly see that particular item max out at 36.73, but my friggin SA Rel to TDC setting will continue climbing up into the mid-40's (which, of course, hits knocking).

I'll try out a new ESC Module, verify the plug on the knock sensor and try to 'remove' EGR operation. More to follow.

ChevyTycoon

iTrader: (1)

My screen shot of my SA Rel to TDC displaying 50 Degrees, even though the SA Rel to Ref Pulses is maxed at 36.56.

Is the SA Rel to TDC "supposed" to equal the SA v RPM v Load table?

ChevyTycoon

iTrader: (1)

Great article. It got my hope's up, so....

I just burned, and test drove, a chip with my best guess as how to disable EGR:
EGR (Off) 0.00%
EGR (On) 99.61%

My test drive still encountered 48 to 50 Deg (SA Rel to TDC).

So either I don't know/have the correct settings to properly disable EGR OR this suggestion didn't work out for me. If my best guess is incorrect, please don't hesitate to shout out!

EagleMark

I really don't know your bin/mask but usually there is an EGR enable temp, set that to max! So it can never be that hot to enable. Is what I do... you don't have an EGR so this must be done anyway.

RBob

iTrader: (1)

The engine needs to be under load for the forced knock test to run. Hence the need for the hills. Note that in your post above (#3?) you mentioned that the knock counts never went above 1. If the ECM is now retarding the timing, the knock counts should be higher.

As for the SA relative to TDC, need to add the base timing to the maximum spark advance scalar of 36.73*. So the max at-crank timing is 10.55* + 36.73* = 47.28* BTDC.

The min SA and max SA are constraints of the distributor.

Can disable the forced knock test by setting the enable temperature high (151* C):

LC22C: FCB 173 ; 90C, (194) MIN COOL TO ENABLE error 43
; CALIB = (Deg C + 40) * 256/192

There is also a minimum LV8 value that can be set high (255):

LC22D: FCB 170 ; If LV < 170, Disable error 43

I haven't looked at this code enough to know something, but other code that has a forced knock test won't add PE SA until the test passes. Don't know if this is true of the $32B mask or not.

But can always add some PE SA directly to the main SA table.

RBob.

ChevyTycoon

iTrader: (1)

Thanks, RBob. I am a bit ashamed to admit that although I know the lines you provided are directly from the source code, I don't yet know enough to know how to edit those lines. Getting sidebar'd here, but even reading the white papers out at TP (there is a paper about creating ECU's), I don't know how to actually find Location 22C (LC22C) using only TP. Even opening the $32b XDF/ECU via notepad doesn't provide me anything close to resembling LCXXX identifiers. Again, thats a sidebar topic but I sure cannot thank you enough for providing me what is very valuable information and I apologize for not being able to apply it (at least at this stage of my self-education).

Either way, I'm going to try a new ESC module and verify knock sensor wiring per your earlier suggestions.

more to follow and thank you folks for your inputs!

ChevyTycoon

iTrader: (1)

Hey EagleMark - I found a scalar for EGR operation at a certain temp and set it at 180 deg C.

but still didnt help me. Thanks though!

RBob

iTrader: (1)

ALT+T (Tools) then Item or Parameter Finder (version dependent), Then select the at this address and plug in 22C.

RBob.

ChevyTycoon

iTrader: (1)

Thank you. Unfortunately, I do not have a 22C location in any $32, $32b, $6E or even $6e Extended mask. Additionally, using Parameter Finder, searching for 'this address' or 'words in the description' or 'words in the title' for knock, error, 43, 22D, 22C or any other combination I can think of, nothing is found (except the scalar's i've already mentioned)

Admittedly, the $6e mask does include many more variables of "knock" than either $32/$32B. But still nothing at 22C.

ChevyTycoon

iTrader: (1)

On another interesting, but maybe equally frustrating, note....

there are two different ESC modules available:

86 - 87: P/N 16022621 (alternate p/n 16126761)
88 - 89: P/N 16052401.

I have the 86-87 ESC in the truck - so maybe its incompatible with the 1988 Bin's and $32B mask that I've been using for the last year.

Going to try a plain, old 1986 Bin and $32 mask to see if that may be of any factor...more to follow.

Oh yeah, $55 and $79 respectively so I'm going to eliminate any other possible variable before replacing things. But the more more bin/mask combinations I'm going through - the more it points to a physical issue as RBob is pointing out.

Off for Elk Hunting for the next two days so Happy New Year to everyone!

RBob

iTrader: (1)

The ESC modules are compatible across the years. No issue there.

Enjoy the hunt and to you a good year.

RBob.

Tuned Performance

iTrader: (92)

I have one , not sure if im priced right.

https://www.thirdgen.org/forums/engi...lectronic.html

garyk1970

Two thoughts for me.
1) there should be no knock counts while normaly driving.you mentioned 1 count.counts should show 0......(in a perfect world).
2)your ecm isn't seeing knock.its trying to induce it.can you tap on knock sensor key on engine off and see knock.
like rob stated look to see if wrong wire is hooked up and knock sensor is in the correct location.do you have another knock sensor to try?

ChevyTycoon

iTrader: (1)

Thanks for the plug! Sorry, but I purchased one on my way home and didn't see this in time. Good Luck!

EagleMark

I thought the same thing! Key on engine off! Was just proved wrong in another thread, engine needs to be running for this test. I re-read the manual and it does state engine running. Not sure if this applies to all ECM/PCM?

ChevyTycoon

iTrader: (1)

So, the latest update attempting a new ESC Module....

Purchased a new module, installed it then drove. Net-net is this did not solve anything: still hit knock then threw a code.

I tried a few different things to try to attempt to narrow down on anything and what I learned today is somewhat wierd:

I drive the truck up a hill, hit 1/2 throttle, watch the SA Rel to TDC increase up to the mid to high 40's, hear the pinging and knocking, then see the Retard Degrees log 6.80, then see the SES light come on and stay on. Knock Counts never move past 1 (from the time I start the truck)

Wierd thing: i drive with teh SES light until the next stop light, turn off the truck, wait about 3-5 seconds, start the truck: knock counts jump from 180 - 220's and the SES light goes out. I can then, at stop lights, stop signs, whatever, stop the truck and restart the truck and my knock counts increase. So...during startup and especially turning off, knock counts increase by the dozens. So either the knock sensor is registering something when I turn it off, or something else entirely is messed up.

Either way - I'd say the knock sensor is working. Combine that with a new ESC module and i'm back to square one...

garyk1970

Another thought is only hand tighten the knock sensor......overtighten will make it too sensitive. Are you are timing is set correctally so the ecm is in its expected "window" of timing control?

Tuned Performance

iTrader: (92)

never heard that one !

garyk1970

Then it sounds like you haven't been tuning long.......there's possible timing inaccuracies in every car.
even verifying 6* timing on mark can be wrong.I've seen 5* off because of a combination of issues :
1) hall effect sensor off on Dist
2) harmonic balancer markings off
3) timing tab marks off
4) timing tab mounting off

I'm talking fractions of an mm......it adds up...

This explains why some cars will accept more timing than others........the op maybe should redeuce timing a couple degrees ......

Also the knock sensor torque spec on a buick grand national is 15 ft lbs ...these cars should be simular.....don't use and thread tape.don't over torque.

EagleMark

That I have heard all of.

But I did not know over tightening of Knock sensor could change what it reads... or why plummer tape on threads would effect reading? I thought the sensing end of knock was in end, not in body or threads.

But now I could understand overtightened could cause damage/squeezing of sensor on end...

garyk1970

My above post sounds harsh.that wasn't my intention.thread tape could possibly desensitize the KS.overtighten could make it too sensitive ...
accurate KS info is crucial .....sound travels through the body of sensor.....imho

EagleMark

No harshness received or intended!

Just like to learn and share. Little details like this intrigue me!

garyk1970

Cool.it went out to tunedperforc too.......I have a GN that's in the elevens with a bone stock drivetrain and bolt ons. The Gta is a new challenge to me. I've learned alot here already.when dealing with these ecm's of this era and Turbo charged regals as well, knock becomes one of the most talked about subjects.

ChevyTycoon

iTrader: (1)

Good input Gary - but I'm 100% validated on my initial timing setup. I am currently at 8 Deg BTDC. Verified by an adjustable timing light, as well as a marked balancer (done when I was degree'ing the cam).

As for your #1 - I may need to verify that; any suggestions how? But if my balancer marks = timing tab = timing light = 8 Degree's, this may not be worthwhile to chase.

As for the knock sensor installation - to be honest, its been over a year since I built and installed the motor, but I'm recalling that stock GM replacements include thread sealer on them. I would not have used anything further than that. But I also have to consider that a faulty KS could be contributing nonetheless

I think it may be worth repeating: My SA will continually increase right up to 48-50 Degrees REGARDLESS of my SA table(s) settings. I don't think this is a mechanical issue but a programmed one.

EagleMark

Might want to go back to a stock bin and varify? Paste in your VE and spark table, make as few changes as possible at first Sometimes you make so many changes somthing goes wrong...

EGR disabled and EGR timing tables zeroed just in case

What about the forced knock test RBob was pointing out?

.

ChevyTycoon

iTrader: (1)

I dug out my original chip, Eagle. And what do you know? No SES Code, no pinging, no SA exceeding my tables. So I'm going to try and change just a few variables at a time to see how/when I encounter my condition.

It's frustrating in that I've gone through stock 86, 87 and 88 Bins using both $32 and $32B masks that DID cause my problem. If I compare my original chip with any other stock bin - I have over 600 differences. I'm thinking that maybe the masks that I'm using just aren't correct.

For example:
$32 has a table called Spark Correction - LV8/2 vs. Coolant Temp. Located at 0x102
$32B has no such table that correlates Spark, Load or Temp. No location defined for 0x102
$32B-Extended has a table called Coolant Compensation Spark vs. Coolant Temp vs. LV8. Located at 0x10F

This is where I'm still learning: determining which mask works best with which bin...

In theory, I should be using a $32 since its a 1986 'setup', but understand that $32B should be interchangeable....however, at least with the masks that i have, they may not be.

I just don't know which mask my original chip used

EagleMark

Sweet!

We've been having that issue with what mask too with some oddball cars like a 2.5L TBI engine with a 1227727 ecm... which I think ended up being $3F... we did not have a bin to look at.

What is your original bin?

There is a way to look at hex in bin and see what mask, but I don't know how to do that...

Found it! We were talking about a certain ecm though, I'm not sure this works on all bins...

ChevyTycoon

iTrader: (1)

Wow! Cool information. Even better, it worked!

9th byte=32

RBob

iTrader: (1)

But that doesn't tell you if it is $32 or $32B. At this time the best bet is to get an bone stock BIN for the '89 MY. It will be maskID $6E, and go with it.

RBob.

Tuned Performance

iTrader: (92)

I have sent him all the 32, 32B and $6e I have ever personally read that are unmodified so he should be set.

ChevyTycoon

iTrader: (1)

pic of the Hex

ChevyTycoon

iTrader: (1)

Well, crud. Thanks RBob! Sounded like a good idea though

Yes, it's probably about time I venture into $6E territory - I have been very reluctant yet to do so since I don't feel very confident on my knowledge of the lesser masks, $32/$32B.

And tunedperformance has sent me about 40+ factory bins so I have quite the library started now.

EagleMark

Your missing a couple key points, one Rbob recomended it, two Mark Mansuar author of TunerPros car is $6E. It will be easier and better support.

Tuned Performance

iTrader: (92)

lean cruise , no cruddy ninth injector !

ChevyTycoon

iTrader: (1)

Two VERY good points, Eagle!

Tuner: Ha. What could possible go wrong?

RBob

iTrader: (1)

If that hex editor is displaying the BIN correctly, that BIN is corrupt. Don't use it.

RBob.

Tuned Performance

iTrader: (92)

omg that jacked !! sorry I told you arar or arap forgot you had a 305. use

any of these bcc apym, apyr, apyt ,apyy ,anyh, anyc, anyd ,anyz

ChevyTycoon

iTrader: (1)

RBob: that is, uh, my original chip..

Does this look any different? (if i check the Byte Swap button - this is what i get)

RBob

iTrader: (1)

That's better. There is a hex editor built into Tuner Pro. Open the BIN and hit CTRL+H. No need to guess on whether to byte swap or not (little endian versus big endian).

RBob.

ChevyTycoon

iTrader: (1)

Today, undertaking the dive into using $6E (downloaded directly from TunerPro website)

maybe over-thinking this, but there are a few items that i'm unfamiliar with and seeking guidance (using my original Bin + $32B experience) with which items to modify. Using the stock APYM Bin as my baseline

Flag's:
Analog MAF Meter - should i check or leave unchecked?