my son and I pulled the 85 tpi 305 out of his z28 and put a mild 350 in its place....060 over 4vr w/small dish pistons, 350 oldstyle smog heads, cam from a friends chev crate motor(friend of a friend of his older brother)
car is an 86(it was a basket case 4bbl car) has shorty headers, 3" exh w/o converter to 3" split muffler w/3" tips...3.73 posi rear w/ sway bar and 4 wheel disks
16" wheels (non factory)

engine runs, but hard to start, power ok, smells rich, tcc locks up way too soon and slow to unlock(overhauled 700r4 4 months ago) dies on decell occasionaly
knock sensor not hooked up at all (old 1 wire style)

Is the 85 ecm and prom ok for this swap, or should we find a newer system(money is tight as 17yrold has no job)
what else should we have changed

 

The TPI ECM will work just fine, but you need to reprogram your PROM in order to get the tuning just right.

Also, since the knock sensor is not hooked up, that will throw the ECM off.

Since that system is an 85 TPI, it has the Mass Airflow Sensor in it, which was known to be unreliable, especially since 85 was the first year for it.

If money is tight, you could modify your system to a Speed Density rig. You would have to eliminate the MAF and add in a Manifold absolute pressure guage, which would require some re-pinning of the engine harness as well as swapping in a new ECM. A V6 ECM would work just fine, as long as you re-pin it properly and use a V8 PROM and MEMCAL.

 

Ha ha. That's a good one.

Get a Corvette chip or convert to the later ecm. See

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

 

Oh, and by the way.-

'85 Corvettes used 24 lb. injectors. If you use the Vette chip right-out-of-the-box, you should use those injectors vs. the 19 lb. from the 305. Back in 1985, a car dealership installed a 350 engine into a Trans Am (pre-chip programming days) using the Corvette chip and it worked just fine.

The good thing about the '85 ECM is that it is simple. It should accommodate a lot of differences regarding gear ratios, etc. You may also want to check out www.corvetteforum.com - look thru the C4 sections.

As far as the '85s durability/reliablility goes, I've had my MAF for 22 years now and have no problems.

 

Thanks Guys...
The corvette prom and injectors sound like the way to go.
I stole back my brothers advance timing light so we are going to work on that some today..
I am a Trucker, so not much time to work on his car

He is driving it everyday again, his older brother raised the idle to about 750 in gear and it is not dying so much