Im swapping in a 350 into my 89, 305 T/A.
Im pulling out a 305/TPI, 1989 T/A
The donor motor is a 350, TPI from a 1990 GTA. I have the ECM and chip and no wiring harness.
I know That the 89 is MAF and the 90 motor is MAP.
Can I re-use my 89 wiring harness and pin in the MAP sensor or do I have do swap out the harness too?

 

http://www.eecis.udel.edu/~davis/z28/ecm_swap_730/

Bear in mind there is no reason why you can't run the new engine as a MAF setup reusing all your existing MAF parts
and with a 350 MAF chip installed in your '165 MAF ECM
( also need a 350 MAF knock sensor to replace your 305 one)

 

Got ya.
However, heres my, sorta, delimma.
The ECM I bought with the motor has a Stage 2 performance chip already installed and I'd really like to keep it.
http://www.jetchip.com/Shop/shopdisp...ppp=10&catID=1)
Computer Chip | Stage 2 | Auto Transmission Part #: 19014S

How about this option....
Buy another chip....
http://www.jetchip.com/shop/shopdisp...sppp=10&vall=1
Computer Chip | Stage 2 | Auto Transmission Part #: 18905S
That chip is for a Pre-90 350/TPI.
209 bucks is certianly better than 650+ for a painless wiring harness.
Any advice....

 

Don't be fooled by Stage 1 / Stage 2 / Stage 3 chips everyone is selling.. Most people won't ever notice any HP gains or performance with any of these chips.. If you stay MAF, it will be easier to put modifications on your engine that it will automatically be able to compensate for.. Now, It is easier to use the 4 wires from the MAF and install a MAP sensor. However don't forget to remove the MAF power relay and Burnoff Relay once you do this. THey will no longer be needed. Hopefully the 7730 ECM you are trying to install already has the VATS antitheft system shut off in the chip or you will be fighting that issue until you find someone who can remove it with a chip burning program. This is easily done and I doubt you will be overly excited with it once done.

 

Just finished the teardown today...
Heres my findings on the new motor.
-Its a '90 MAP setup and I'm putting it onto an '89 MAF car. An issue I'm currently working through.
-The TPI setup is unmolested. (No grinding, no port matching) I'm very happy with that.
-Runners are completely undented, still has the distributor cover. WOW!
-Plugs were well used but didnt show any signs of excessive carbon buildup or any signs of water leakage.
-It didnt have a thermostat in it?!?? (Maybe an amateur attempt to resolve overheating issues)
-Intake and heads had never been pulled.
-All pushrods are dead straight and well within length tolerances.
-Roller lifters are fine, no abrasions/scratches, Just signs of normal wear.
-Typical gunk in the upper oil galley, and again, no signs of water.
-Head decks are typical, the gaskets were intact, no leaks anywhere.
-Cylinders need honed but have no scratching/pitting. (Will measure them later)
-Heads are stock, obviously, valves still seat perfectly (Clean and reuse? May Do a valve job, Ive never done that before)

Rolled the motor over on the stand and removed the pan.....
-Rear main seal intact. No leaks
-Oil pan gasked is perfect
-2 bolt mains - as expected
-All 5 Main Bearings are fine
-3 of the 8 rod bearings were spun (all on the 2 front journals) Wonder why! Was this the result of the Perfromance chip on stock GM bearings?
I didnt pull the harmonic balancer yet so the crank, cam and timing chain are still in the block.

Pics coming as I can upload them.....

Amazing thing I learned. You can tear these things down with a MINIMUM of tools. Literally. I was shocked. Had a short breaker bar and 3 or 4 sockets. Had it done in less than 2 hours.
Another cool thing I learned. I started this and totally forgot to buy any Breakfree or PB Blaster. Brake Fluid makes EXCELLENT breakfree!!!!

 

ibmtech
I havent addressed VATS yet.
Corrrect me if Im wrong here...
The key is read, that ohm reading is sent to a VATS module that verifies the proper ohms and sends a Yes/No (1 or a 0) to the ECM. That signal tells the ECM to unlock the Starter and Injectors.
If Im understand you, My current key wont work once I pop in the new ECM?
This assumed VATS has not been programmed out. The website makes no mention of it so I assume its still in the chip.

 

VATS is an automatic feature built into the AUJP eprom and 7730 ECM used with a Map Sensor.. It isn't hard to remove with the right burner and software. But, with an aftermarket chip, I doubt if you will be able to uncheck that box in the programming.. I learned that lesson a long time ago and never forgot it.

 

AHA! found the perfect solution to my VATS. Radio Shack.

Im going to get a 10K and a 1K Cermet Potentiometers. One for gross and one for fine advustments.

Example: Solder them in series.....
My current ECM looks for a 3.01 OHM reading. I can set the 10k pot to 3kohms, then fone adjust the 1kp pot to .01, a total of 3.01. Ill connect that to the VATS leads and the car should start.

The 15 GM VATS values are easy to find, just google them. I will set my pots to the known values and start turning the key.

Why didnt I think of this before. A homemade VATS interrigator.

 

No it doesn't
ECM looks for a fuel enable signal from the VATS module which reads the resistor in the key.
Read
https://www.thirdgen.org/vats_passkey_system

Installing the resistor only fools the module into thinking that the correct key is in place; if the module has faulty outputs
(to starter relay or ECM ) or the starter relay is faulty, the resistors will do nothing to solve a no start problem

In your case you would be best to bypass the relay altogether because with the resistors permanently in place
it is redundant as a anti theft measure and just another potential source of problems

Even easier solution is to install a fuel enable signal generator
http://www.bakerelectronix.com/products_vats/
wired direct to the ECM , do the starter bypass as noted and VATS is gone altogether

 

vetteoz
My current, running, car is a stock '89 with no VATS issues. I swapped out the ignition cylinder years ago. It had become so worn that the key wouldnt turn the cylinder anymore, VATS still worked just fine. I simply installed a new, non VATS cylinder, and left the old cylinder with the wires connected in the hush panel, old key inserted. I do not have resistors. Never had an issue since. My VATS decoder and relays are all working fine.
Once the new motor and ECM are installed, I'll pull the old key and go the resistor route once I interrogate and find the right OHM value.