alright i got this 89 car today with no engine... and i have a 86 305 TPI in my garage ready to be dropped in....

i took a quick look at it today and figured out that the bulkhead connecter in the engine bay is the same as the 89 car but under the dash where the ecm is there is a few connecters that come off the harness that go through the passenger side fender...(guage wires)? are different connecters.. except for 2 of them..

did these wires get changed in between 86 and 89? what are the wires for?
and would i be able to splice the wires together if they are the same ones but just different connectors?


any info is appeciated


thanks
adam

 

Was the '89 car originally TPI?

I know '89 didn't have the cold start injector, but not sure of any other differences. It isn't the gages, because they don't go through the ECM bulkhead connector.

You realize the '86 system technically isn't emissions legal in an '89.

 

yes the car was originally an L98 and i have a an LB9 that im going to put in its place.

yeah i realize that its not legal.. but how is a smog guy going to know that the engine is an 86 unless he knows about 3rd gens?

as long as i have the air pump in working order isnt that all that matters?



and what are those connectors? they come off the the ECM wiring strand and are supposed to connected to something in the passenger side dash.

 

ok i was looking at the passenger side dash wiring again of the 89 and there are 4 connecters that are supposed to connect to the ECM strand

89 harness:
1 is a 7 pin connector(86 harness has this)
1 is a 8 pin connector(86 harness has this)

1 is a 2 pin connector(86 harness has this)
1 is a 6 wire connector(86 DOES NOT have this)



the 86 harness:
1, 3 pin connector that is not on the 89 harness... what is the 3 pin connector for?

 

im sure someone has ran into this problem?

 

Sorry I have no info on this ,but I'm in similar deal I'm putting a 406 flat top in an 88 RS,with a TPI and computer out of a 86 IROC with a 305. So I'm watching your post with intrest.I'm talking to a GM mech to see what were getting into, but no info yet.If he comes thru I'll let you know.Thanks and Good Luck on your car. Chuck

 

could these wires be related to the VATS?

i've been searching all over and cant find anything

 

This is gonna sound really dumb, so bear with me...

If your 89 L98 car still has the wiring, then why are you trying to change it? Wouldn't you just drop your TPI sbc where the other one came from? What is so different that you can't just drop in the engine and use all your maf stuff? Aren't they both maf cars? you can re-pin for the 86 ecm...

 

the car does not have any of the wiring for the engine in the engine bay... that is why im using the 86 harness... if the 89s harness was still there i would just use it on the 86 engine


when im talking about the wiring of the 89 i mean the under dash wiring that connects to the to the strand that goes through the fender and comes off the ECM wiring of the 86 harness



just to make it clear even though its kind of confusing how im explaining it...

my full 86 wiring harness that is connected to the engine has 1 plug that connects under the passenger side dash that doesnt match my under dash wiring of the 89 car

the 89 has a 6 pin connector
the 86 has a 3 pin connector

all the other ones match except for these 2.


my question is does anyone know what these connectors are for?

im going to ge pictures tomorrow maybe someone will reconize them.



once again any info is greatly appeciated

 

ok im even more confused now... alright out the the 4 connectors that come off the ECM strand and connect to the underdash part of the harness

only 2 match up heres one..


ok heres the first connector that i just figured out did not match up.
89 is first then 86 is second picture

 

heres the second connector that is not matching up...
this is kind of confusing...



the first picture is of the 89 connector under the dash

the second is the underdash connector i cut out of the 86 before i got rid of the car... they look somewhat similar except for the blue wire

the third is showing how the 3 pin connector on the 86 engine harness connecting to the small piece of 86 underdash harness i cut out of the car
the connector it connects to is a 6pin connector