Bill usn-1

Any one have a valid GM part # for the NETRES chip. I run the 7747 and have searched by the number off the chip, the chip numbers listed on Ludis' site and the GMECM site. I have not been able to get any of the number to cross on the partsdirect or other parts sites. There's lots of V6 chips in the JY but the V8 7747's are getting a little scarce. Anyone work at a GM dealership that can tap some resources?? Thanks.

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Bill
USN-1
77 Innocenti (mini) 1275cc 7747 TBI/DIS
75 scout XLC 345/727/JP-D300/3.73's/33's/SOA/EFI

Bill usn-1

anyone?

junkcltr

What you wrote doesn't make sense. Clearly state your question.

Bill usn-1

OK, I'll try it again.

There are 2 removeable chips under the cover in the 1227747 ECM.
1 contains the bin file and is a 2732 chip.

The other one is the NETRES chip or limp home chip.
There are 2 of them that I know of. 1 for the V6 and 1 for V8's.

I am looking for the GM part number for the V8 chip.
So I can go online or to any GM dealer and give them the number and they can look it up and order it.

Right now the number on the top of my chip is 16060837.

DIY-EFI list this...54995 Custom limp home fuel controller chip

And Ludis list this....CALPAK IDs: “Z”: 16051637
Which I think is the number for the V6 chip.

I know of several people that have picked up V6 7747 ECM's and just swapped the chips for the V8. The chip was only about $14.
But I can not locate the part number now!!

HTH to clearify

Thanks

RBob

I can't help with the part number. However, you may be able to use the term CALPAK and an app such as a '90 full size van with a 305 or 350 in it (IIRC vin K).

The other thing is that the V6 CALPAK will work on an 8 cylinder application. There isn't any cylinder select function to worry about. The V6 CALPAK will provide slightly larger PW's then the V8 CALPAK while in limp mode. There is a write up someplace that describes the function of the various resistors. These would need to be modified anytime the stock injectors or fuel pressure is changed.

RBob.

Bill usn-1

Thanks RBob.
I and others I know have ran into misfires and poor running when trying to use the V6 chip.
So to avoid problems I always use the V8 chip.
Are there any base line parameters that are used from the Calpak in any of the normal operations?
How about start up?

Can you completely remove the calpak on the 7747 and not affect the operation?

I never thought it made a difference which one you used till guys using the V6 ecm on thier V8 (with a new BIN)were having a hard time getting it to run right until they changed it out.

RBob

Removing the CALPAK will cause an eror code to be thrown and a solid SES. Don't know how it affects ECM operation.

Now I'm curious about running a V6 calpak on an 8 and having problems. I'm need to review my notes on these things and maybe even try a V6 calpak on a live engine. I can't see it being a difficult issue to correct.

RBob.

Bill usn-1

A couple years ago I swapped one out myself on a motor I had a good tune on.
I didn't see any difference.
But then I had a guy I was helping via email and he couldn't get it to stop loading up. He swapped out the V6 calpak and it ran fine????

Since then I just always use the V8 calpak.

Not knowing code, I'm dependent on guys like you.

Thanks for anything you can provide to clearify.

Brent

16060836 is the one.

16060837 is the number of the chip without the plastic carrier and IIRC its a GM internal number.

Bill usn-1

Thanks,
That did it!!!

Item Number List Core Price Price
16060836 $21.07 $0.00 $15.80
Electrical - Ignition system - Module - Calpak
Stamped 16060837 1988 - 1991
Add to Cart Contact Us
16060836 $21.07 $0.00 $15.80
Electrical - Ignition system - Module - Calpak
Stamped 16060837 1992 - 1993
Add to Cart Contact Us
16060836 $21.07 $0.00 $15.80
Electrical - Ignition system - Module - Calpak
Calpak 1992 - 1995

And it works for the 16051637/6

The best prices I found were on http://www.gmpartsdirect.com/

RBob

I wonder if the other folks were in limp mode. In that case, yes, they would load up the engine. In reviewing my notes there is pin 9 that is very much different between the two. On a V8 it is open, on a V6 it is 4.6K to ground.

That calpak pin (9) goes to the RFD which also has a cap to ground and a pullup to ignition switched 12 volts (according to the schematics). In my notes I have a question mark as to what it is for. If it does make a major change then cutting pin 9 on the V6 calpak takes care of it.

RBob.

Bill usn-1

Since I wasn't there I can't verify if they were.
From their description it sounded like they weren't in limp-home?

Do you know if there are any other values that are different between the 2 calpaks?
cutting pin 9 would be a good test for a bench.

I think I have a V6 calpak so as soon as my truck arrives over here, I will do a little experimenting.

Thanks for the research RBob.

And the PN Brent.

RBob

The mux select, rfd enable, and calpak present resistors are the same. The 9 RFD programming resistors are different. If the engine is stock, the injectors are stock, then using a V8 calpak is the best bet. Once anything changes then it doesn't matter. This is because the calpak calibration no longer matches the stock engine. It is interesting that GM used the same calpak for the 305, 350, and 454 engines in vans, f-body's, and Caprices.

RBob.