I am planning to do the 305 to 350 swap this winter and have a few ?'s.With the exception of the distributer wires and the 9th injector will the 86 harness work with an 89 tpi motor?I dont want to swap the harness unless absolutly necessary.What about the ECM?does it need to be switched?

 

Yea, it will work other than what you mentioned. The actual MAF and fuel pump relays on an 89 are different (some of them) but serve the same purpose, so you dont need to worry about changing those.

 

Whats diff about the dist ? Ive interchanged them.

-- Joe

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/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
1989 Formula 350 4-bolt mains, Forged .030 TRW pistons, SLP 51010 Roller Cam, Comp-cams roller lifters,
Summit 1.5 roller rockers, World Products Sportsman II 2.02/1.60 heads, Edelbrock TPI Intake,
Cloyes Double Roller timing chain, Mellings oil pump: 13.5 @ 100.23 MPH

Since close of track : Ported SLP runners, Ported Plenum, AFPR, Autometer 100lbs F/P gauge, A/F ratio gauge, MSD 6AL.

http://www.joesperformance.com

 

86 is the coil in cap style, 89 is the divorced coil setup. The wires going to the distributor on the 86 use a different connector than the wires that hook up to the module mounted to the distributor on the 89. The coil wires on the 89 are also not on an 86.

 

The alternator wiring will be on the wrong side of the engine. '86 has it on the passenger side, '89 has it on the driver side. Connectors for the alt are also different I suspect.

Distributor wiring as previously mentioned is different.

Lack of 9th injector I think was also mentioned.

The firewall harness at connector C100 (firewall, just under the relay bracket on drivers side) may be pinned differently. Some 3rd gens run the fuel pump feed there, for example, while others run it thru C207 which is near the ECM and has the dashboard outputs.

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1982 Z-28

See http://www.mycar.net/mafb/registry/detail.cfm?id=276 for details

 

On that subject the AC wires are on the opposite side too, but both of those arent part of the harness that runs to the ECM. If he uses the 86 accessories it wont matter anymore. The 89 oil sender is also different than the 86, it incorporates the fuel pump cutoff in the sender rather than having 2. That wiring is also not a part of the ECM harness.

 

Thats wild. I pulled apart a few 87s and they didn't have HEI dist. What year did they change over to the externally mounted coil?

I know our vette has a HEI coil and its a 90,
but all the TPI f-body's thats passed
through my shop were external mounts.

-- Joe

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/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
1989 Formula 350 4-bolt mains, Forged .030 TRW pistons, SLP 51010 Roller Cam, Comp-cams roller lifters,
Summit 1.5 roller rockers, World Products Sportsman II 2.02/1.60 heads, Edelbrock TPI Intake,
Cloyes Double Roller timing chain, Mellings oil pump: 13.5 @ 100.23 MPH

Since close of track : Ported SLP runners, Ported Plenum, AFPR, Autometer 100lbs F/P gauge, A/F ratio gauge, MSD 6AL.

http://www.joesperformance.com

 

Most changed in '87 'vettes later.

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Chronologically challenged. But still kicking!
'92 CAMARO RS
305 TBI 5/spd (now TPI)
B4C Alt.
Cam change:TRW 198/210 ,450/.460 114 LSA
Stock TBI manifolds
'85 IROC 3" Cat. back Exhaust
14.94-92.00 mph
SDPC base and "350" Vortec coming soon!
'69 camaro-BB/Lenco,1050 dominators, /Pump Gas/no drugs 8.97-150+/3200lbs.
SoCal Thirdgen F-Bodies

 

I am still undecided on which accessories to use,the 86 v-belt or the serpentine system.I will probably go with the serpentine setup and extend the wires the the accessories.I guess I have to use the 86 oil sending unit?
Will I have any problems with not using the 9th inector?
How about the ecm,do I need to change it or get a 87 or 88 350 chip?Will it matter?

 

I'd ditch the cold start setup and run an 89 chip. The stock chips arent really all that expensive, just got one a couple weeks ago for 38+tax. The 86 sending unit setup will work fine.

If you have the serpentine and dont mind a little rewiring and need to charge the AC (or have the means to do so), then switch it over.

 

how will the 89 chip work without the VATS?Or does the chip have nothing to do with it.

 

DOH!
Forgot about that little detail. It wont work without the VATS decoder box That is unless someone else knows a way to feed the ECM the correct signal.

I have burning stuff so I kinda forgot about it, sorry. It wont work so well without the cold start, you will have longer cranking times than you normally would. My 86 was real stubborn about starting when I forgot to reconnect it. You could always get someone to make a chip for you with the vats turned off though. Pretty simple change.