Iowa280zx Posted May 22, 2009 Share Posted May 22, 2009 To start off.. I have a 83 280zx that I recently did the turbo swap on. My engine is from a 81, I have installed a 83 dizzy, running a efi harness from a 81 that has the drop resistors bypassed and beyond that everything is stock. The car previously had a 81 turbo ecu that went bad. I tested it with a buddies that also had a 81 unit and it started, drove and all that jazz. I found a turbo ecu from a 83zxt, installed it and am having some odd problems. The car will start and idle but the second you even attempt to hit the gas it will die. Also if you pull the afm harness off the car stutters for a second but keeps on running. If memory serves when i had the 81 ecu on the car wouldn't run at all without it hooked up. I searched all the wiring diagrams that you can get and didn't find any real differences between the 81-83 setups. Is there something I'm missing here or did wiring change that would cause that to happen? any ideas? Quote Link to comment Share on other sites More sharing options...
RUZN Posted May 23, 2009 Share Posted May 23, 2009 Yeah well I did the ECU Swap.. everything was dandy. Then 4 weeks later I start running rich and worst off at a stop light I go to go and almost die.. all I see is puffs of black smoke out back and the smeel of raw unburned fuel... Nooo Idea! checked friggin everything re wired everything, just changed thermostat. tried rerouting coolant tubes from turbo (cause I swapped in a 300zxt turbo) nothings worked. Best I can do is its now bad mainly Just when turbo kicks in at 2500RPM thats after after 5 timing sessions LOL.. tried every timing possible some work better at highway some better at idle but nothing cures my over fueling at about half throttle... Quote Link to comment Share on other sites More sharing options...
RUZN Posted May 23, 2009 Share Posted May 23, 2009 O2 sensor totally carbon fouled and only putting out .01Volts LOL put in my stock one and Boom 0.45-0.22 Volts and runnning great again yay! Quote Link to comment Share on other sites More sharing options...
roger.svoboda Posted May 25, 2009 Share Posted May 25, 2009 the ecu you are using could be bad. when I did an engine swap on a z31 (turbo for turbo) the original ecu that worked fine with the original engine went sour. Had to use the one out of the donor car. Quote Link to comment Share on other sites More sharing options...
Iowa280zx Posted May 25, 2009 Author Share Posted May 25, 2009 are there differences between the 81 - 83 afm's? I could see that making the car do what it did, but on the other hand there really isn't much to those units. Quote Link to comment Share on other sites More sharing options...
roger.svoboda Posted May 27, 2009 Share Posted May 27, 2009 if you look inside you will see lots of chips, transistors, resistors, diodes and capacitor on two boards I wouldn't call that not much. Pulled one apart that wouldn't work found a blown diode. I'll replace that and try it out. actually that one is off a z31 so maybe the 280zx is much simpler. Quote Link to comment Share on other sites More sharing options...
BleachZee Posted May 27, 2009 Share Posted May 27, 2009 Sounds a bit like a 280ZX running with no AFM plugged in... I tried this once and the car would idle but die as soon as the throttle was touched. Also make sure your head and block temp sensors are still plugged in. Quote Link to comment Share on other sites More sharing options...
DuoWing Posted May 27, 2009 Share Posted May 27, 2009 That's a possibility what Bleach said. You may have a bad connection somewhere or right at the AFM. Also check your timing, check for vacuum leaks, and again make sure your CHTS is plugged in. Even if that's plugged in it can go bad. Every Z I've had so far that had a CHTS has had the CHTS go bad. Quote Link to comment Share on other sites More sharing options...
BleachZee Posted May 27, 2009 Share Posted May 27, 2009 I've never seen an L28 CHTS go bad, but for some reason the Z31 (same sensor type from Nissan) goes bad all the time... weird stuff Quote Link to comment Share on other sites More sharing options...
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