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Discussion Starter #1 (Edited)
Hello all,

New to posting here. But I need some advice / direction. I recently replaced the engine in a 1996 C1500 Chevy P/U. New long block. Replaced the injectors, plugs, MAP sensor, rotor, Dist Cap, Cam sensor etc. etc. ... When I was all done, I cranked the engine and it ran like a top! Up until it got warm (to temp) then it began to miss. It got worse and worse until it wouldn't run anymore. I got a DTC code of 341 (cam sensor). I let it cool down, checked all connections to the cam sensor, checked the voltage to the sensor and all checked out ok. Once the engine cooled down, it cranked and ran fine again. Hitting on all 8 and running like a sewing machine ...until it reached temp again... then it started the same ole crap. ... Anyone have a solution?? ....

Thanks,
 

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Sounds like you have a crappy cam sensor that goes to ____ when the motor is warm.
 

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I know it keeps telling you #341, but you checked it & it's testing ok so I'd start looking elswhere. Maybe the temp sensor? Works fine & richens it for cold running, but goes out of range when it warms up & leans the mixture out so far that it just can't run.
 

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Thank Stephan and Murdog ... but I've replaced the cam sensor (twice) and it still does the same thing. Gotta remember, it didn't do this before I put the new engine in it. So I don't have any real reason to suspect a bad cam sensor accept that the code it's throwing says so. But now, ??? everything is pretty much the same on the engine as it was before I pulled it. The only difference is a new timing cover, new MAP sensor (I broke the old one) new rotor cap, dist. cap, plugs thermostat, and spider injectors..... so what could be causing this??
 

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Did you check the cts or the wire connection to it? You've done just about everything else, I would start double checking the wiring looms at the connections (every one that you disconnected & re-connected during the engine swap) Sometimes the wire locks in the connectors aren't good & when you plug them in, the wire will get pushed back into the plug instead of making contact.
 

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Discussion Starter #6
Did you check the cts or the wire connection to it? You've done just about everything else, I would start double checking the wiring looms at the connections (every one that you disconnected & re-connected during the engine swap) Sometimes the wire locks in the connectors aren't good & when you plug them in, the wire will get pushed back into the plug instead of making contact.
Thanks Stephan ... but I FOUND IT!!! It was the Crank Sensor!!! .. go figure. I suppose it didn't like being cleaned up and installed into the new timing cover. Thanks for all of the input ... but the crank sensor and the coil were the only two things that I could think of that might have been the culprits as they're both known to give problems of this nature once they get to temp.
 

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So it tested good, but it was bad? lol .... Murphys law :-(
Be aware that a bad cts can act just like what you had with the crank sensor, in case this starts all over again tomorrow ha ha ha
 
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