240sx89

hey guys sorry if this question has been asked before but i search and could not find anything.


Well heres my Problem.... I have an 1989 240 that I swap a DOHC motor into. Used the 89' stock everything and rewired the 89 harness. So I have and 89 ecu and harness with a DOHC Motor. The Car starts, runs fine at an idle with an occasional misfire and light to no smoke. If i drive it , its has a mild misfire or sputter and no smoke. If you get on it , it gets a rough misfire and smokes alot.
Anyone have any ideas?

Light Bluish/Grey Smoke
New Cap, Rotor, Plugs and Wires.
Adjustable Fuel Pressure Regulator set at 35psi. at an idle
AEM Intake
Plugs are dry when checked so its not loaded up with gas.

Please Help Me Out Thanks!

RediJedi

get a DOHC ECU

rollhard

The SOHC harness and ECU will NOT work on the DOHC motor. If I were you, I would not start that engine again until you have the DOHC harness and ecu. I hope your motor isnt damaged.

240sx89

Why Dont Start it again? What could/could have happen?

BigVinnie

iTrader: (2)

First off the timing between the 2 engines are completely different.

The IAC and TPS are positioned different, and have a different voltage output.

DOHC's come with a knock sensor.
Stupid idea to run sohc ecu's on a dohc engine that has all different equipment.

240sx89

What you mean the timing is different? Whats different about the two?

240sx89

Also what could possibly happen to the motor?

dkdeleon

First of all the (sohc) is a single overhead cam and the (dohc) is a duel overhead cam. the sohc is 12 valve and the dohc is a16 valve. hence, the timming differences.
Not to sound like a dick but what are you doing swaping motors yourself if you do not know the difference between the 2 motors?

dkdeleon

?????

240sx89

Because I do know the difference between to two motors. I also know that neither motor has a cam angle sensor and the timing can be set on both motors so that extra cam cant make that much difference. so if you could please give me a better explaination on why it wont work. Cause i actually looked it up and big vinnie is wrong, the voltage output on those to sensors are the same.

240sx89

????

240sx89

Hey Guys

I got the car running right!! It can be done with the SOHC ecu and wiring harness.If you pull the distributor out a little and retard the timing a notch or two, then set the timing with a timing light, the car will run beautiful! Thanks guys for trying to help!