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Engine swap problem

2271 Views 7 Replies 4 Participants Last post by  Chillerguy
Hello, I bought a Honda off a friend as a project it had a cracked block, I swapped the block from a local junkyard and now I am having trouble starting it.

To further explain after swapping it the engine started I let idle for a bit and then turned it off ( it was over heating, changed the thermostate) , 5mins later I went to start it again I would get weird rpm spikes then the engine dies while at 2000 rpm.

Noticed the key sign showing up when the engine dies, but the key is the one that came with. the car and i did not swap the ECM and it does lock and unlock the vehicle if it was an immobilizer issue the car wouldnt start at all..?

Any input would be appreciated I tried almost everything I dont want to just sell it to a junk yard I encourage any help. thank you in advance.
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If the green key is flashing and the car shuts right off, somethings up with the immobilizer. It might need another key reprogram.

For the idling issues - the throttle body is electronic and when it's messed with, the computer gets confused and starts idling weird until it gets a TPS reset with a special scan tool. This could be your issue so I would check for fluctuating idle when first starting the car.
If everything is connected correctly, I would inspect the PCV Valve and the EGR valve. The PCV Valve gets old and the ball will not rattle which will need replacement - an OEM one will run around $20 on eBay. The EGR Valve gets dirty over time and could get a nice cleaning with (I think) brake cleaner.

This is my top knowledge when I was facing idling issues a year ago. I did these 2 jobs and I now have a steady idle.
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