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Ka24de swap Smoke/misfire problem

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Old Jul 13, 2006 | 10:04 PM
  #1  
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Ka24de swap Smoke/misfire problem

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!
Old Jul 14, 2006 | 09:51 AM
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get a DOHC ECU
Old Jul 14, 2006 | 04:21 PM
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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.
Old Jul 14, 2006 | 10:11 PM
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Why Dont Start it again? What could/could have happen?
Old Jul 15, 2006 | 08:46 AM
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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.
Old Jul 16, 2006 | 12:10 PM
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What you mean the timing is different? Whats different about the two?
Old Jul 16, 2006 | 12:14 PM
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Also what could possibly happen to the motor?
Old Jul 16, 2006 | 08:18 PM
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Originally posted by 240sx89
What you mean the timing is different? Whats different about the two?
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?
Old Jul 16, 2006 | 08:22 PM
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?????
Old Jul 16, 2006 | 08:47 PM
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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.
Old Jul 16, 2006 | 09:20 PM
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????
Old Jul 18, 2006 | 07:30 PM
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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!
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