hi everyone,

i just swapped a 350 TPI from a 89 formula350 into my 87 T/A (305 auto)
both cars have 1227165 ecm's
the 305 t/a has a acxs prom, the 350 ran nichly with a anyf.

the engine starts with the acxs but runs a litle rough and rich since its a 305chip.
with the anyf chip or better memcal the engine doesn't start.

my guess:
the formula350 was vats equipped, my 87 t/a is not

i would would put the correct resistor in some place, to simulate the key, but the 87 doesn't even have the wires for that.

does someone know a way to put the resistor directly onto the ecm wiring connector instead under the steering column?

any help would be greatly apreciated



Roman

 

The resistor in key is read by the VATS decoder module which then sends a signal to the ECM

If you don't have a VATS module in the car then no amount of resistors anywhere will do anything.

All you can do is either get a new prom with VATS programmed out
or use this module wired to the ECM to supply the correct fuel enable signal the ECM wants to see

http://www.bakerelectronix.com/products_vats/
http://www.fieroaddiction.com/passkey.html

 

the module works great, i've had it in all my thirdgens, just make sure you bypass the starter enable relay as well

 

Thanks a lot for the quick answers.
by the way, does someone have a pic of the stock vats decoder module?
since i've got to parts cars around i pretty sure got a working one, just no idea what to look for.
just for the moment i found a old ABWN prom that seems to work, but i'll need to test drive first.

The other two prom's i've got, ANYF and ARAP dont fire up.
is there a kind of list where i can look up what prom or bin file fits what aplication?

my actual combination is a 87 T/A with 7165 ecm and 87' wiring.
The 350 TPI engine, as far as i know came oroginal from a 87 or 88 IROC.
I just swapped in a T-5 and a borg warner 3.27 rear.

maybe someone knows what's the right bin file for that aplication.



Roman

 

1987 F body,350, auto, 3.27

ARAP ;'89 Corvette 350 auto (w/VATS )
ANYF :'89 F-Body 350 auto

The ABWN you have in at present should work fine
There was no T5 behind a 350 so you won't find a factory chip for that

 

$25 for a VATS bypass module?

you can actually make those for around $1. and around $4 if you want to put it in a nearly waterproof case.

 

its NOT the resistor based one.
the bypass module actually generates the 30hz signal that the ecm needs.

Now if this is what you're talking about i will be interested in knowing how you can make this with $1

 

i'm quite serious, you can build a 555 based circuit that will make the 30 or 50 Hz signal for far less than $1.

 

oooh sweeet tahn we are on the same page, would u share how to do that?

 

let's see... for a 50Hz signal, you would need a 555, 1 100nF(.1uF) cap, a 15K and 150K resistor, a .01uF cap and that's about it....

for a 30Hz, the 555, the same 100nF cap, a 24K and 240K resistor and the same .01uF cap.

http://www.taydaelectronics.com/serv...5-Timer/Detail
555, $.10

http://www.taydaelectronics.com/serv...pacitor/Detail
10 X 100nF cap, $.10

http://www.taydaelectronics.com/serv...HM-OHMS/Detail
10 X 15K resistors, $.10

http://www.taydaelectronics.com/serv...HM-OHMS/Detail
10 X 150K resistors, $.10

http://www.taydaelectronics.com/serv...pacitor/Detail
10 X .01uF caps, $.10

http://www.taydaelectronics.com/serv...HM-OHMS/Detail
10 X 24K resistors, $.10

http://www.taydaelectronics.com/serv...HM-OHMS/Detail
10 X 240K resistors, $.10

and of course, you could assemble all of this without a PCB if necessary, and throw it in a small project box from radioshack.

 

So this guy is not struggling to make a profit selling bypass modules @ $179 ?

http://newrockies.com/buy-from-me/

This is his circuit

 

HA, unless he has some REALLY oddball way of bypassing it, yeah he's making a killing.

 

nice circuit, i'll try that.
last weekend i did some drifttraining at hockenheimring racetrack and got some test driving miles too.

The ABWN chip for driving works pretty well, but has has still the two problems that i swapped that chip for the ANYF when the engine was in the 89' formula.

1st. i've got a unstable idle speed, jumping between 1100 and 800 rpm's, an within about 15 to 30 seconds going to lower rpm's till the engine stalls.

when the car is rolling, even at minimum speeds, the engine will idle at 1300 rpm's.
tryed everything, new pcv, new vacuum lines, new iac, still same problems.
when i swiched the prom in my 89 formula some years ago from ABWN to ANYF i had from one moment to another perfect stable idle speed at about 600 rpm when car was standing as well as when rolling.

 

Still some trouble to get things going....

got a prom reader/burner now as well as tuner pro.
just trying to find aout what are the differences i several bin files.

just found the 87 bins like ABWN and ACXS will work on a 32b mask,
as the ANYF or ARAP will go on the 6E mask.

I tried ANYF with the VATS enable flag unchecked, reburned the chip, engine still does't fire up.

is this still a VATS problem, or will the 89 chips just don't work in a 87 car?

 

Did the new chip verify correctly?
Either type will work with the '165 ECM
Most tuning use 6E and delete the CSI function used with 32b

 

yes, the new chip has varified.

is there something on the chip telling the ECM what typ it is, 6E or 32b or simthing on the car side, wiring harness?

If use the wrong mask, several tables will look pretty goofy, especialy the MAF tables and desired idle speed seem to make no sense at all. ignition on the other hand looks prety the same on both masks...

so i guess something will tell the ECU where to look up the correct data esp. since the 6e files are 32k compared with the 16k 32b files
or am i totaly on the wrong way.

the coolant temp switch in front of the intake is missing and plugt on my engine, so CSI is disconectet anyway
it starts a litle harder, but since i'm used to cards without choke, thats no problem.

 

o.k. now i found what went wrong!

one morning i woke up and thought it is imposible there are a bin file 16kb large, and one with 32kb, twice as large and they should both work on the same mast and in the same ECM.
something must be wrong with that files...
I found that guy whou burned some chips for me couple of years ago did instead to burn the file offset to the end of the chip, took the file two times behind each other and filled the 256 chip that way.

when i read that file, the editor looked at the first file only, but the ECM looked up the second file at the last position at the chip.
so whatever i changed in the editor, hat no efect to the car.

figured that out, things get going and the changes in tuning did work.

So now if someone new to the whole thing reads this:
The files for the 7165 ECM, 86-89 MAF cars are 16Kb in filesize.
if you read them from a 256 chip, tell your reader it is a 128 chip so you end up with the correct file size.
if you burn on a 256 chip you'll start to burn at 04000 position.