My friend recieved this from his empire motor sports contact:
"I know you didn't ask for any advise, but I hate to see your friend stuck.
If he greatly increased his injector size he will need prom changes. The
85 ecm is lousy compared to the later MAF ecms (1227165).

The options your friend has, as I see it:

-Contact Ed Wright or such tuner. (many chips are bogus, Ed Wright seems to
be popular)
-Convert to the 165 ECM and contact a tuner.
-Convert to the 165 ECM, hit the Prom board at Thirdgen.org, and burn his
own."

I have decided I am going back to the stock 19#/hr unjectors right now, I am moving to texas in 3 weeks, need the car running right. It ran fine before i swapped em, but that was with a stock 48mm throttle body.

Question is: Am I going to run way lean if i leave the 58mm throttle body on with the 19# injectors? Should i go back to stock?


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1985 Trans Am, 355 TPI, 2 stage NOS
1999 Z28, Stock with plans

 

I wouldn't think you would run lean with the larger TB because you are still restricted if you have the stock (or non-ported) manifold or a non-ported plenum. 58mm is overkill I would think unless you have a heavily modified 350. The engine is too choked up downstream from the TB.

Also, what size injectors did you put in to replace the 19#? If you went 22 or 24 you should be ok, anything larger then yes, you should burn a PROM for it, but then again some of the more knowledgable guys here might tell you different.

One thing is true though, and I know this for a fact. The '85 "870" ECM sucks big time. Best mod ever done... getting that POS out of there. I have a link on my web page to the instructions on how to swap to the 165, thanks to Mike Davis.

------------------
Kevin Irving
85 Trans Am WS-6, 305 TPI, custom burned '86 PROM with '87 "165"ECM, Accel Supercoil & 8.8 Wires, Rapidfire #2 @ .055", MSD 6AL, 1.6:1 Roller tipped rockers, Homemade AFPR, K&N cone, no airbox, Aluminum Driveshaft, Wonderbar, TB Coolant Bypass, Ported Plenum, Descreened MAF, Syclone Fuel Pump, JET Airfoil, Mobil 1 synth in all but transmission.

15.556 @ 86.65mph, Nov 10, 2000.... I know it sucks.. but it will get better!

http://www.geocities.com/transam85tpi/

Member - The Tidewater Trans Am Club, Norfolk VA http://www.geocities.com/ttacva/

[This message has been edited by Kevin Irving (edited May 04, 2001).]

 

i have 24# in there now and they flood me like a bastard. I am putting the 19# back in this weekend. I dont have time to get a swap going as i am moving in 3 weeks. Its a 355 now, but the car was originally a 305. Its modded kinda nice, decked, .501 lift cam (int/exh), siamesed ruinners, ported maf, ported plenum, stock manifold, upgraded electrical system, ceramic coated headers, cat back, torque converter.

it could get bogged down in the stock manifold, but from there on out and up to it, should be free flowing. Thats why i am concerned i guess, i dont want to lean out, especially when i touch off the nos.

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1985 Trans Am, 355 TPI, 2 stage NOS
1999 Z28, Stock with plans