Seanjcoyle

Hi guys. I current bought an engine from a 96 fb oft with 40,000 miles on it. This engine I want to swap into my 93 z28. My questions are...

What sensors do I need to swap between the two?
Can I use my original harness from the 93 with the 96 vented opti?
Are there any mods I should do while the motor is out?

Thanks in advance for your help!

Injuneer

For the Opti, you will need a new short harness from the gray connector on the bracket on the passenger side of the intake manifold to the Opti. Available from EFI Connection, if the 96 short harness doesn't come with the engine.

You will need to keep your 93 throttle body, since it has the TV cable connection for the 4L60 trans (which trans in your 93?), and the 93 IAC motor and connector are different. Also need to keep your 93 fuel rails and intake manifold. Or you would have the relocate the fuel lines. The 93 rails are better for the 93 batch fire injectors. Use the 93 injectors, unless you plan to get a new chip burned for the 96's larger injectors.

Use you 93 exhaust manifolds if you plan to keep EGR and AIR. 93 plumbing is different. And you want to use your 93's single-wire O2 sensor in the driver side manifold.

Swap your 93 knock sensor into the 96 engine. Impedance is different.

Your oil pressure sensor is above the oil filter. 96 is o the top edge of the block behind the intake manifold. Just have to reroute the wire.

You will not have anything to connect to the 96 crank position sensor. No problem, not needed (it's for OBD-2 misfire detection). Just leave the 96 CKP sensor in the timing cover to plug the hole.

Remove AIR pump from 96 engine (bolted to front of block), keep your 93 pump (bolted to chassis), and use the AIR/EGR plumbing from your 93.

93 tach runs directly off the coil, with a filter in the line. Keep that circuit intact, connected to the 96 coil. 93 coil has a double connector, 96 coil has a single connector, but it's a better coil. Either rewire to connect to the 96 coil, or swap coils if you don't want to rewire.

Seanjcoyle

Thank you Injuneer! And yes I do have the 4l60 trans. Are the egr/air pump worth keeping around or should I just remove it? I live in South Dakota so emissions are not enforced here

Injuneer

Do you have a cat? AIR is used to heat up the cat on cold start, which reduces emissions and prevents damage to the cat. No effect on performance. If you don't have a cat, you don't need the AIR pump. Since it only runs for a couple minutes at startup, it is not part of the tailpipe emissions test.

EGR is used to quench high combustion chamber temps under operating conditions that produce them (e.g. - lugging the engine at low RPM), and prevent detonation (knock) and reduce NOx emissions. If you have a tailpipe emissions test, you could come out high on NOx without the EGR. Again, no effect on performance, as long as the EGR valve isn't leaking. It is not used at WOT or above 3,500 RPM. Deleting the system technically needs some tweaks in the program since there are apparently some minor timing changes that take place as well.

Seanjcoyle

I do not have a cat. I bought the car a couple weeks ago. List of mods I was told it had done to it when I bought it.

Rebuilt transmission with red alto friction disks and Kolene plates
Eaton posi differential with 3.42 gears
Lingenfelter Performance Aluminum Driveshaft
Eibach Pro-Kit Springs,Bilstein Shocks, sphon Front and rear sway bars, Boxed trailing arms, Adjustable Pan-hard bar, Poly graphite lower control arm bushings,K&N Air Intake with LT4 elbow, MSD Optispark, water pump, AC Delco Ignition Module and Coil, Rear Hatch Supports, Radio rebuilt to facilitate non-Bose speakers, both window motors, New A/C compressor, filter drier and expansion valve, drivers wheel bearing, Ball joints ,Tie Rod Ends,ssCamaro rims
Magnaflow muffler, poly trans mount

Injuneer

Here's a great chart showing the LT1 differences from year-to-year:

From Shoebox

http://shbox.com/1/4th_gen_f-body_ye...onversions.pdf

Seanjcoyle

Thank you

Seanjcoyle

Just out of curiosity... Would it be worth it to do the complete swap with a 96 wiring harness and ecm?

Injuneer

Toss-up..... 93 OBD-1 and 96/97 OBD-2 are the most difficult to tune. 93 because of the need to burn a chip, 96/97 cost of the software. OBD-2 has more emissions checks and codes that have to be deleted. Any PCM after 93 is looking for a 4L60E to control. If you got the 96 trans with the engine, that would not be a problem. The 96 would have to come with the MAF sensor, or you would have to buy one. You would gain misfire detection with the 96 PCM.

96 PCM has the advantage of a replaceable knock module, allowing the use of the LT4 knock module if you go to full roller rockers. On the other hand, it's getting hard to find an LT4 KM, and if you find one it can be very expensive.

You will have issues trying to connect the 96 engine harness to the 93 body harness connectors. Shoebox has the pinouts for the various years. Tach wire might be an issue. Not sure if there are differences with the 93 vs 96 PCM with any interfaces to cruise control or ABS.

No easy answer.

Seanjcoyle

Ok thanks. I think I'll stay with the 93 harness.

Seanjcoyle

Update on my project:
I learned that the new engine must be a 94. It has a spline drive non vented opti. And a throttle body with no TV cable provisions. Which tells me it's a 94(correct me if I'm wrong)

Injuneer

93 and 94 Opti's are identical. Throttle body is different as noted.

Seanjcoyle

Should I use my msd opti or keep the original

Injuneer

How old is the stocker on the 94? Do you even know if it's a GM unit?

I'm no fan of the MSD, but it would probably be better than a high mileage GM unit, or without regard to miles, better that any aftermarket unit.

Seanjcoyle

The engine is only suppose to have 40k on it. I took a file to the points and the rotor to clean the little amount of carbon buildup that it had. It looks like an original gm non vented opti