jlchenier

i just took out the computer out of my 90 gtu and the plugs are completely diffrent than my 86gxl how can i get this 86 gxl motor to work in the gtu or where can i find out how to do it

Gibenstein

iTrader: (2)

Cuz you have to swap the ecu to. Meaning if you do it the easiest way is to swap the 86 gxl motor along with the s4 ecu as the wiring harness's are different I believe. There like 10 bux on ebay or you can find them cheap here.

jlchenier

i got the ecu what about the plugs in the car do ihave change then to

Gibenstein

iTrader: (2)

What plugs ? Spark plugs ? I dunno what plugs you speak of ?

Gibenstein

iTrader: (2)

Here http://www.rotaryresurrection.com/series4swap.html

jlchenier

the plugs that go to computer in the gtu there differnt than the ones in the 86 so do i have to change the interior wiring harness

jlchenier

if someone can call me on this i would greatly appreciate it you can call me collect i dont care at this point this is driving me nuts 508-765-7633

Gibenstein

iTrader: (2)

From the website
"Remember that anything electronic, or anything that an electronic part bolts to and would not otherwise bolt to on the older setup, must be retained from your old engine. Your car still has to think it is an s5, even though it has an s4 block."

jlchenier

ok that help a little bit but i dont have the gtu motor all i got is the gxl motor with eveything on it

Icemark

The only way you are going to get that (s4) motor to work in a stock ECU/harness 89-91 coupe, is to swap the front cover, and use the 89-91 harness, plugs, sensors, MOP, Front cover, etc onto the S4 bare block.

You would have to re-wire the whole car otherwise if you are trying to use a S4 engine, harness and ECU in a S5 car.

And next time you post... put the question in the title... I have updated the title for you.

Parastie

What icemark said is true. I have a S4 engine in my S5 car. What needs to be changed is the front cover (because you have to use the electric OMP) and the flywheel. also, you'll have to make a block off place for...something that the s4 engines have and the s5 does (i don't remember exactly what it is, but it's at the very top of the engine, underneath the intake manifold). Also, you'll need to grind down some of the posts on the engine that support the intake manifold, the S4's supports are too high. Goto http://www.rotaryresurrection.com and read up on the S4-S5 swap, all you'll need to know is there!

jlchenier

OK BUT i dont have the s5 motor got the car with no motor im just about ready to go carband get rid of all that stuff anyone know where i can get the s5 frontcover and intake and stuff like that

Parastie

Check ebay or the buy and sale list on this forum.

RotaryPower27

Hey if you still have the engine from the 90 you can use all the external components on your s4 block and then just plug it directly into the s4 electronics. That way you dont change anything electronic. You have to make a egr block off plate becaust the s5 doesnt have it on the block like the s4. I made mine out of a peice of metal then i got some cork gasket and some silicon and made a sandwich and bolted it on

RotaryPower27

guess i should have read all the posts. disregard my last one. except for the egr block plate you still will need that

Icemark

Without any of the S5 parts, you are simply f#@ked. Go get the right motor... the only thing that a S4 motor has in common with the S5 is the basic block will bolt in.

But if you don't have anything (including the engine harness) from the S5 motor to put on the S4, then I would probably go stand alone ECU. I thought there was a stand alone now available in the sub $800 range.

And putting a carb instead, is just asking for even more headache.

jlchenier

really i tjought going carb would be easier no electronics on the motor

Parastie

If you go carb you need to take pictures and show everyone. Also, you'll more then likely get worse gas mileage and will never pass emissions if your state has it.

jlchenier

yea i figured that about the mileage but ill live with that as far as emissions no i wont pass in mass. but i got a few ways around it

Icemark

Driveabilty plumits with a carb, as well as mileage and generally even HP (depending on carb tune)... and then you haven't even discussed the distributer problems