CarlosFley Posted September 12, 2014 Report Share Posted September 12, 2014 Hey peeps, so I bought an 88-89 EVU a few months ago and just today got around to installing it. Well, ends up being that it will not idle properly since the swap. It oscillates between 1500 and 1k. It'll literally climb up to 1500, drop to 1k like fuel was just automatically cut off and as soon as it hits 1k climb right back up to 1500 and as soon as it hits 1500 drop directly back down to 1k and so on and so forth. I reset my TPS/ISC with no success whatsoever. I have the magic .50 volts between green/black and green/white, tuned just right, but still nothing. Swapped my 87 back in and she is perfectly fine. Sooo I'm guessing the ECU itself is shot? Idk, give me your thoughts. Thanks. Mods in my sig. Link to comment Share on other sites More sharing options...
StarquestRescue Posted September 12, 2014 Report Share Posted September 12, 2014 I recall a similar report of problems with the isc after a ecu swap, so i would say it is possible. Link to comment Share on other sites More sharing options...
CarlosFley Posted September 12, 2014 Author Report Share Posted September 12, 2014 I recall a similar report of problems with the isc after a ecu swap, so i would say it is possible. So would it be the ISC or ECU? Link to comment Share on other sites More sharing options...
StarquestRescue Posted September 12, 2014 Report Share Posted September 12, 2014 ecu, after all your isc works fine with the old ecu. Link to comment Share on other sites More sharing options...
CarlosFley Posted September 12, 2014 Author Report Share Posted September 12, 2014 Dammit, they sold me a bad ECU Link to comment Share on other sites More sharing options...
ucw458 Posted September 12, 2014 Report Share Posted September 12, 2014 Check for bad capacitors on the ECU. Our ECUs are super hard to break but capacitors do go bad over time and they are easily replaced. Link to comment Share on other sites More sharing options...
Fuze Posted September 12, 2014 Report Share Posted September 12, 2014 Bad ECU's are a rare animal, but I've come across a few over the years. Check the pins on the new ECU and clean them with a small wire brush, small fine file or a little piece of fine sandpaper. A little corrosion buildup on those pins, maybe from sitting on a shelf for a long time, will increase the resistance of the connection and that will cause the ECU to misread the sensors. Sometimes unplugging and replugging a bunch of times will accomplish the same thing as cleaning the terminals. Link to comment Share on other sites More sharing options...
CarlosFley Posted September 12, 2014 Author Report Share Posted September 12, 2014 Bad ECU's are a rare animal, but I've come across a few over the years. Check the pins on the new ECU and clean them with a small wire brush, small fine file or a little piece of fine sandpaper. A little corrosion buildup on those pins, maybe from sitting on a shelf for a long time, will increase the resistance of the connection and that will cause the ECU to misread the sensors. Sometimes unplugging and replugging a bunch of times will accomplish the same thing as cleaning the terminals. Hmm I might try that then Link to comment Share on other sites More sharing options...
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