My VIN Y Northstar runs on the 7730 ECM adapted by Ryan Hess, but it does need tuning and I need help with it.

The problems:
The engine runs rich enough to carbon up the exhaust areas and even the bumper and the rear quarter bottoms if there is a cross wind on a long drive. Ryan told me his programming was intended for a VIN 9 engine, and would likely run rich on my VIN Y engine. The engine also has a significant stumble when throttle is applied in anything more than a gentle increase. Any light jab of throttle makes it stumble before it revs up. Subsequent jabs of throttle before recovery of a stumble sometimes causes enough of a stumble to cause a stall. After a stumble, the idle hunts before settling down. A good jab of the throttle does produce a rich burn black smoke from the exhaust.

What I have established:
The problems are the same even on the second engine I have had in this car. The first engine was pulled after a poor hone/ring job, but still suffered from these problems. The current engine is a new one I got used from a guy who bought it new from Speedway Motors and did not follow through on his project. I have tried a new IAC, 3 different MAP sensors (2 used and 1 new) 2 TPS (1 new and 1 used), 3 different intakes and throttle bodies the two engines, and the problems are unchanged by any trial. I am confident there is no vacuum leak, this has been thoroughly explored. The wiring has been confirmed correct to Ryan's diagram several times just to be sure. But the problems persist. I think it is the richness of the program??

My Questions:
Does anyone have experience tuning their 7730 for a VIN Y Northstar? Would you consider sharing your BIN file?
If you have experience tuning for a VIN 9, do you have any suggestions for tuning to correct my problems on the VIN Y?
Where is a good source of info for tuning using TunerPro? I really don’t relish learning this, but it may be the only option?
Cadillac forums I have perused do not deal with the 7730, but only Cad ECM’s so they seem to be a dead end.
Ryan of Sinister Performance is a 7730 expert, but has told me he is not familiar with the Hess code of a Northstar 7730.
Is there any shop in the Minneapolis MN area that might anyone has experience with and can deal with the reprogrammed 7730?

The engine is bone stock, new, relatively free flow exhaust ( stock manifolds, 2" true dual, dual cats and tip resonators) and transmission is Getrag 5 spd.

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Daviero - 88 N* GT

If I am not mistaken Ryan started with the a1 code to get the dis to work and worked from there.Do you have the equipment to burn your own chips? This link will be some good reading http://www.v6z24.com/jbodyf...m-tuning-t73503.html

Burning my own chips is no problem - I have a Moates burner and have burned lots of chips. I am reasonably familiar with TunerPro from tuning the VSS. I just do not know anything about what to change in the BIN to attempt corrections for the stumble and the richness. I have not found a tuning shop I can go to or where to find info to do the tuning myself. The trial and error approach in my opinion will likely make things worse - I need an educated approach. Thus my search for the educated person or the education for me.

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Daviero - 88 N* GT

Edit:

quote Originally posted by jdv: This link will be some good reading http://www.v6z24.com/jbodyf...m-tuning-t73503.html

This link is aboout the 7730 but does not use TunerPro and is about V6 tuning. Also alot of "nothing posts" to wade through....Thanks for the suggestion though.

[This message has been edited by Daviero (edited 06-13-2009).]

quote Originally posted by Daviero: The problems: The engine runs rich enough to carbon up the exhaust areas and even the bumper and the rear quarter bottoms if there is a cross wind on a long drive. Ryan told me his programming was intended for a VIN 9 engine, and would likely run rich on my VIN Y engine. The engine also has a significant stumble when throttle is applied in anything more than a gentle increase. Any light jab of throttle makes it stumble before it revs up. Subsequent jabs of throttle before recovery of a stumble sometimes causes enough of a stumble to cause a stall. After a stumble, the idle hunts before settling down. A good jab of the throttle does produce a rich burn black smoke from the exhaust.

I had a similar problem with my 7730 when i first installed it. The first thing to do is reduce the "delta TPS vs. accel enrich" table. I found that it was programmed for massive accel enrichments. If it's still running rich after that than you can start taking fuel out of the Main VE table. If you send me your email address i'll send you my current Bin file.

quote Originally posted by Zac88GT: I had a similar problem with my 7730 when i first installed it. The first thing to do is reduce the "delta TPS vs. accel enrich" table. I found that it was programmed for massive accel enrichments. If it's still running rich after that than you can start taking fuel out of the Main VE table. If you send me your email address i'll send you my current Bin file.

Thanks very much Zac. I saw this huge enrichment too....if I remember corectly..from 0.8 or so at idle to 4 to 5 on the injector pulse depending on the amount of throtle snap.
I sent you an email to respond with.
Edit: Zac, do you run a VIN Y or 9?
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Daviero - 88 N* GT

[This message has been edited by Daviero (edited 06-13-2009).]

Stock injectors and stock fuel pressure?

Even with the vin Y/9 differences you should not be seeing any black smoke. Can you get some data logs of the engine running and demonstrate the problems? That would help confirm rich/lean, AE, idle etc.

I can show you how to tune it, but I need to know what the problem(s) is/are first.......

quote Originally posted by ryan.hess: Stock injectors and stock fuel pressure?

All stock Ryan. Fuel pressure was confirmed with a gauge. The injectors have been cleaned and spray tested so I am using those, not the ones that were in the "new" engine. I'll send you some data to look at tomorrow.
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Daviero - 88 N* GT

[This message has been edited by Daviero (edited 06-13-2009).]

Dave,

I didn't get a chance to reply to your PM, my bins probably wouldn't do you any good anyway with my different cams and intake in the race car. That said, to save yourself a lot of time get an Ostrich emulator and get the car on a dyno. Seriously. I accomplished more in 3 hours than I could do in 3 days of "road" tuning.

John Stricker

John the Ostrich emulator looks like a useful tool. I wonder if I can find a tuning shop that already has one - but while $175 won't break the bank but I try to not buy too many 1 time use tools. I likely won't use this again after the car is tuned.

Zac, thanks for the BIN. I ran it and found it lean for my VIN Y too. The BLM is consistently over 128, cruises at 129 or 130, and reaches 140 under loads. Under hard acceleration it goes even leaner. I moderated your revisions but it is still lean. I work on it some more....

Ryan, I did not record anything today. I spent the day with Zac's BIN trying to richen it up. Instead of looking at some data, I have a few questions:

Should the BLM be 128 or slightly less at all times: cruise, light load, heavy load (hill under mild acceleration), and hard acceleration?
If leaning is the objective, should the timing tables be revised too or left alone?
What should the IAC be with the cooling fan on - 20 + indexed 20 for the fan = 40?

Thanks, Dave.

I thought the same thing, Dave, but to be honest, I've quit burning chips since I got it. There are always adjustments you can make, especially in my case with the race car. For instance, we were at evolution autocross school and it was a VERY cold day. Because most of the events we run are in the summer, the car was running way to rich so I plugged in the laptop, pulled some fuel out of the cold temp side, and made things much better. Not perfect, but much better. That's the kind of thing you can do with an emulator and you don't have to have your whole burner equipment as well as take the time to swap multiple chips.

It's well worth it to me.

I can't help much with the BLM because we're tuning pretty much strictly by the dyno and don't really care what the BLM shows so I've never paid attention to it. The part I'm having trouble with now is tuning above 6000 rpm. We are still going pig rich. I'm almost convinced we need a bigger throttle body before we can do much more.

John Stricker

quote Originally posted by Daviero: John the Ostrich emulator looks like a useful tool. I wonder if I can find a tuning shop that already has one - but while $175 won't break the bank but I try to not buy too many 1 time use tools. I likely won't use this again after the car is tuned. Zac, thanks for the BIN. I ran it and found it lean for my VIN Y too. The BLM is consistently over 128, cruises at 129 or 130, and reaches 140 under loads. Under hard acceleration it goes even leaner. I moderated your revisions but it is still lean. I work on it some more.... Ryan, I did not record anything today. I spent the day with Zac's BIN trying to richen it up. Instead of looking at some data, I have a few questions: Should the BLM be 128 or slightly less at all times: cruise, light load, heavy load (hill under mild acceleration), and hard acceleration? If leaning is the objective, should the timing tables be revised too or left alone? What should the IAC be with the cooling fan on - 20 + indexed 20 for the fan = 40? Thanks, Dave.

quote Originally posted by Daviero: Ryan, I did not record anything today. I spent the day with Zac's BIN trying to richen it up. Instead of looking at some data, I have a few questions: Should the BLM be 128 or slightly less at all times: cruise, light load, heavy load (hill under mild acceleration), and hard acceleration? If leaning is the objective, should the timing tables be revised too or left alone? What should the IAC be with the cooling fan on - 20 + indexed 20 for the fan = 40? Thanks, Dave.

Yes, you want to aim for just under 128. BLM will not come into play under moderate/hard acceleration, those would be the power enrichment tables.

Do not adjust the timing. KISS.

Ideally you want the warm idle IAC position to be about 20 steps. Adjust the throttle body stop screw only if necessary. With the fan or AC on, it will be higher. I don't know what it is off the top of my head.

The BLM's are still *applied* at WOT, just not modified.

quote Originally posted by Will: The BLM's are still *applied* at WOT, just not modified.

And if they are being modified, you have problems.

Here's a good reference on how a GM ECM works, with maths and formulas given:

http://sunflower.com/~leroy/P4/

Keep in mind this was for a turbo car, but everything else applies.

quote Originally posted by jstricker: Dave, I didn't get a chance to reply to your PM, my bins probably wouldn't do you any good anyway with my different cams and intake in the race car. That said, to save yourself a lot of time get an Ostrich emulator and get the car on a dyno. Seriously. I accomplished more in 3 hours than I could do in 3 days of "road" tuning. John Stricker

OK. I got myself an Ostrich emulator and have had some time to play with it. My intent is to get the hang of it by calibrating the speedo and not waste time on the dyno when I do go to one.

I have not got the hang of it though - I can't even get the speedo correct.

Tunerpro reads the correct speed according to my GPS, but the speedo output is wacky. My RSC is a little less than 24000 for Tunerpro to read the right speed from the ECM, so the IPD SHOULD be 6 right? But IPD of 6 is way to fast. IPD of 31 is also way to fast, like 50 mph in 1st gear, but IPD of 32 is about 0.6 factor too slow. Since IPD has to be a whole number I am stumped.

A little about the car:
It is a US car with a miles per hour speedo, but I used a diff and reluctance VSS from a Canadian Quad 4 car with a kilometers speedo.

I have some issues about how to use the emulator in emulation mode too, but more on that later....I like to get the speedo set first.

Any ideas? (Sometimes I wonder if these Gremlins seek me out, or if everyone gets them!)

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Daviero - 88 N* GT

The VSS feeds the speedo first which in turn feeds the ECM. Am I understanding you that the speedo is wrong? (as opposed to the TunerPro output on your laptop which is from the ECM)

quote Originally posted by Hudini: The VSS feeds the speedo first which in turn feeds the ECM. Am I understanding you that the speedo is wrong? (as opposed to the TunerPro output on your laptop which is from the ECM)

No, with the 7730 ecm, the VSS signal goes to the ECM, and the ECM in turn has an output signal for the dash and cruise. The dash signal requires a conditioning circiut that is detailed on Darth's website. This is the setup I have.
To calibrate VSS input to the ECM, the road speed constant (RSC) is adjusted in in the BIN file which tells the ECM the pulses per mile(ppm). To calibrate the dash output of the ECM the instrument pulse divisor (IPD) is revised.
The Fiero VSS was 4000 ppm and my reluctance VSS from the Quad 4 is 24000ppm
So the IPD should be 6 to get back to 4000ppm to the speedo right? But this does not work - see my post above.
Tunerpro sees the correct speed from the ECM so my RSC is correct. The speedo does not, so the IPD is not making sense.

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Daviero - 88 N* GT

[This message has been edited by Daviero (edited 09-05-2009).]

Anybody have any experience with the Ostrich emulator and speedo calibrating that you can share?
See my last two posts to see what the problem is. The problem seems to defy logic and I am stumped!

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Daviero - 88 N* GT

I can't help you with the speedo calibration because we didn't use a speedo in the race car when we put the northstar in. We had GPS as well as a Terratrip rally computer that reads off the front wheels via a magnetic pickup.

I believe the ECM delivers a fixed pulse output per mile to the speedo, IIRC. It's very possible that in order to get the speedo to read correctly you might have to have the ECM reporting through tunerpro the wrong wheel speed, if that makes sense to you.

IOW, you can adjust the parameters in tunerpro until the computer is reading correctly as compared to your GPS. At that point, the ECM will output a fixed PPM output to the speedo which may (or may not) be what the speedo needs to read correctly.

John Stricker

Edited to add: Don't make a big deal out of the fact you're using an ostrich emulator. It doesn't matter if you're using that or burning chips, they're both doing the same thing. The only difference is that in one case you hit the "upload" button and change the emulator immediately, in the other you save the bin and then flash it to the chip, which you replace in the ECM. It doesn't matter which way you do it, it all amounts to the same thing.

quote Originally posted by Daviero: Anybody have any experience with the Ostrich emulator and speedo calibrating that you can share? See my last two posts to see what the problem is. The problem seems to defy logic and I am stumped!

[This message has been edited by jstricker (edited 09-05-2009).]

Thanks John. I was hoping you had this figured already. I'll just have to keep trying. I have already adjusted the roadspeed constant (RSC) in the BIN so Tunerpro and the ECM see the correct speed verified by my GPS. It is the darn instrument pulse divisor (IPD) that I cannot figure out to get the speedo to read right. My reluctance VSS is 24000 ppm, the speedo requires 4000, so the IPD should be 6? But IPD of 31 shows way to slow on the speedo and IPD of 32 is way too fast :-(
This is why I am stumped.

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Daviero - 88 N* GT

I too have the 7730 and the Ostrich. I'll check to see how mine is wired. Could easily be as you described. The stock Fiero goes VSS->speedo->ECM. Did you rewire yours to go VSS->ECM->speedo?

EDIT: I just checked the wiring diagrams and the VSS does feed the ECM first on the 7730 conversion.

I'm using the $8F code so I cannot offer too much. On mine the IPD is 1.00 as I'm using the stock VSS with a RSC of 4000.43. It sounds as though something else is going on with the code. Check the "Edit Item XDF info" by right clicking the Road Speed Constant. Under the Conversion tab at the bottom mine shows a formula of 7372800.000000/X + 0.000000 . Yours similar?

You could try using 31.50 for an IPD. If that doesn't work maybe modify the .xdf to allow 1 or 2 decimal places. Mine is showing 8 bit, floating point, 2 significant digits.

[This message has been edited by Hudini (edited 09-08-2009).]

quote Originally posted by Hudini: I too have the 7730 and the Ostrich. I'll check to see how mine is wired. Could easily be as you described. The stock Fiero goes VSS->speedo->ECM. Did you rewire yours to go VSS->ECM->speedo? EDIT: I just checked the wiring diagrams and the VSS does feed the ECM first on the 7730 conversion. I'm using the $8F code so I cannot offer too much. On mine the IPD is 1.00 as I'm using the stock VSS with a RSC of 4000.43. It sounds as though something else is going on with the code. Check the "Edit Item XDF info" by right clicking the Road Speed Constant. Under the Conversion tab at the bottom mine shows a formula of 7372800.000000/X + 0.000000 . Yours similar? You could try using 31.50 for an IPD. If that doesn't work maybe modify the .xdf to allow 1 or 2 decimal places. Mine is showing 8 bit, floating point, 2 significant digits.

Yes, mine is the same Hudini, for both the RSC and the IPD. Your post gave me more info about Tunerpro though, since I had not used those windows before. Thanks for your insight.

It seems that the IPD cannot be a decimal number, but I see by the IPD conversion formula that of IPD= 1.000000*X+0.000000 that I should be able to change the formula to force a decimal? I'll try this.

What I would really like to know though: Why is IPD = 6 incorrect, and how can IPD of 31 possibly be too fast while 32 is too slow? To solve the problem one has to understand what is wrong. I do not. Otherwise it is just blind trial and error.

Surely I do not have to tear apart the trans to install the nylon gear and analoge VSS on my Quad 4 diff to solve this problem?

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Daviero - 88 N* GT

I know I typed up a reply that said this... whahoppent?

Anyway, if the IPD is stored as a 4 bit value (I don't know that it is or not), then the values it can take on are from 0-31. If you try to make it 32, it will recycle to 0.

Try numbers between 6 and 31. Trial and error.

Been a long while since I posted.
I had fun this summer once I figured out the Ostrich tuning, logging, and fooling with the data. I have the lower end of the maps tuned way better now looking at the BLM and the INT numbers but the high end has to be done on a dyno. Something for next spring.
I abandoned the speedo since I could not figure it out, but I have to do it eventually.
I have tried every number from 1 to 31 for the IPD. 1 to 30 are way too fast. 31 is too slow. 32 goes way to fast agian!
The ecm spped readout showing on TunerPro is bang on right. Go Figure?
I am using a Getrag 5 spd with a Quad 4 diff and notched wheel with an inductive VSS
It is wired correctlly - I have checked several times. I do not have a ground from the speedo, only one wire from the conditioning circuit to the speedo - purple if I remember correctly. The yellow ground is not used. I read this and I'd have to dig to find it. Is this correct? Might this be the trouble?
In desperation I could do one of two things:
1. Take apart the trans and go back to the nylon gear VSS drive - alot of extra work.
2. Put stick-on numbers on my speedo - pretty crappy lookin'

[This message has been edited by Daviero (edited 01-02-2010).]

If nothing else works, a Dakota Digital speedo signal convertor could work.

quote Originally posted by Will: If nothing else works, a Dakota Digital speedo signal convertor could work.

Yes, I don't mean to discount that Will, but what I have should also be able to be made to work. It must be able to be figured out. Theory is to compensate for higher RSC with the IPD, but my speedo still defies this logic.
I have also read that the Dakota Digital output is rough at low speeds?
Maybe I have to try IPD numbers higher than 32? Does this make since given the HEX protocol of the programming?

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Daviero - 88 N* GT

My IP divisor is "6"... I don't know where that number came from (some formula.. it's actually 128 decimal), but it is hex 80.

The IP divisor works in set increments. Values like FF, 80, 00, etc. I'm trying to dig up the GM document on the IP divisor... But you should be able to take the decimal # 256 and divide it into 8ths and convert them back into hexadecimal for some numbers to try. I would plug them in using a hex editor or tunerpro's hex edit...

Unfortunately I don't have a copy of tunerpro on this laptop, but I'll see what I can find...

edit: post my link:

http://northstar.7p.com

[This message has been edited by ryan.hess (edited 01-06-2010).]

I totally forgot about translating the value to hex... d-oh!

Info on the IP divisor:

code:

---

00h     0        = do not divide (aka div by 1)
80h    128       = divide by 2
40h    64        = divide by 3
C0h   128+64     = divide by 4
20h    32        = divide by 5
A0h   128+32     = divide by 6
60h    32+64     = divide by 7
E0h   128+64+32  = divide by 8

---

Hex value, decimal value, IP division.
Please note: I have not tested these values, they were pulled from the net. But even if the division is not per the table, the hex values should work to perform *some* division.

[This message has been edited by ryan.hess (edited 01-07-2010).]

Hurray!! And I mean it!
This problem took me over a season to correct! Whooda thought that a divisor of 6 would require a number of 128 for the IPD?
Thanks Ryan and Will.

I actually got really frustrated before seeing your responses and jacked up the car in the shop to try several IPD's while stationary, using the ECM vehicle speed input in Tunerpro to compare to the speedo. I had calibrated the ECM value by GPS earlier. This was way faster than road testing - should have done it earlier. I found by sheer luck that IPD = 134 and 138 and140 and 142 all had the same result but was about 6% slow. After reading about your numbers Ryan, I did a search for GM IPD values on the net and read some more. IPD 128 works the same as all the other numbers, and I revised my RSC to fine tune the speedo readout 6% faster for the same Tunerpro Tach readings.
Now to figure out the digital cruise I have hooked up but not working yet.......

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Daviero - 88 N* GT

Darth pointed me to this thread. Does anyone know if a 7730 ECM will work on a 2002 Northstar? Lost another job so I am getting ready to start a swap sometime this spring.

quote Originally posted by OH10fiero: Darth pointed me to this thread. Does anyone know if a 7730 ECM will work on a 2002 Northstar? Lost another job so I am getting ready to start a swap sometime this spring.

Aftermarket ECM required for this year if Im not mistaken.

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Is this where I insert something witty?

[This message has been edited by mcaanda (edited 02-13-2010).]

Can anyone confirm this? And while on the subject of 02 N*, what was different about the engine that prevents me from using the 7730 ECM to run it?

quote Originally posted by OH10fiero: ...what was different about the engine that prevents me from using the 7730 ECM to run it?

Ignition system from what I have been told is the biggest reason in requiring another ECM. The later model N*'s have a coil on plug system where as the prior years do not.

But you still have to send a signal to the plugs to tell them to fire, so what is different between the igition moduels that do not allow the ECM to work it, if that is the only problem then maybe there is a way to make it all work after all.

quote Originally posted by mcaanda: Aftermarket ECM required for this year if Im not mistaken.

As mentioned in the other thread:

quote HP Tuners says they support tuning of the 2006-09 Cadillac Northstar PCMs including the 2006 Cadillac DHS which was offered with the non-VVT LD8 and L37

I believe the 06 DHS PCM might work with the 02 N*; assuming HP Tuners can successfully disable VATS in the 06 PCM (their software SAYS it can).

-ryan

Looking at their site the cost to get one car running is a bit high, I know for a fact that I do not want to spend that kind of money.
Anyone know who already has this software to tune a car once I get the swap done? If not I will need to come up with something else to do this.

If I recall correctly, Ajxtcman was working on a setup that used an LS1 PCM for the newer northstar engines.

Edit to add link
https://www.fiero.nl/forum/Forum2/HTML/087521.html
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* 97 Olds Cutlass DD
* 86 Mustang SVO Rear Ended, R.I.P

* 86 Fiero GT, Soon to be Northstar

[This message has been edited by 17Car (edited 02-14-2010).]

quote Originally posted by Darth Fiero: I believe the 06 DHS PCM might work with the 02 N*; assuming HP Tuners can successfully disable VATS in the 06 PCM (their software SAYS it can). -ryan

Hey Ryan, I cant seem to locate the other thread, but that is actually really great news if it can infact be done. Could you link that please?

This would / could change the way that I end up wiring my N*. I have the ECM already, but it could go either way w/ the chance of putting a GM ECM in there.

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Is this where I insert something witty?

quote Originally posted by mcaanda: Hey Ryan, I cant seem to locate the other thread, but that is actually really great news if it can infact be done. Could you link that please? This would / could change the way that I end up wiring my N*. I have the ECM already, but it could go either way w/ the chance of putting a GM ECM in there.

It was discussed in my 7730 swap thread for Fiero 2.8's here: https://www.fiero.nl/forum/F.../HTML/000088-24.html

quote Originally posted by 17Car: If I recall correctly, Ajxtcman was working on a setup that used an LS1 PCM for the newer northstar engines.

I don't want to speak for AJ because I don't know if what he was working with was a newer generation engine or not.

But I do know GM used a 1999 LS1 PCM on the Shelby Series 1 car that ran an Aurora 4.0 V8 (smaller version of the Northstar). The 99 Shelby Aurora PCM (as I'll refer to it) was programmed to work with a manual transmission and earlier generation Aurora/Northstar (1999-earlier). There is tuning software for these PCMs (which I have) but they will not work with a later Northstar because of the different crank sensor setup used in 2000-newer engines and it will not work with a 4T80-E transmission.

So unless AJ has found an LSx PCM that works with the later 2000-newer Northstars, you are stuck with either using a 06-newer DHS PCM tuned using the HP Tuners software OR an aftermarket ECU. This is what appears to be the case based on what I have read. If anyone has different info, please chime in.

Sorry to hijack the thread...

[This message has been edited by Darth Fiero (edited 02-14-2010).]