Tons of backfiring when turning throttle.

Krimzonbear

Standard Bore
Joined
Dec 22, 2016
Messages
4
Location
oklahoma
I recently got my 06 rocket iii running after it died. it was having a high idle issue (3k plus). it eventually stopped running. i replaced a map sensor and the crankshaft position sensor and the fuel injectors, it now runs and idles nicely enough. However when i go to turn the throttle my tac drops to 0 and the bike dies. when it warms up it doesnt die but wont go over 1.2k rpm and backfires like no one business. i drained the gas and put in some premium with an octane booster, along with some seafoam. ran it at idle for an hour it runs smoother but still will not go over 1.2k rpm without throwing a fit. I think it may be the TPS but the bike is not throwing any codes. any ideas or suggestions?
 
I'm surprised you didn't replace the TPS first (before map sensor - and crankshaft position sensor usually just need a clean) with the high idle problem.

When you do replace it remember not to torque that hex screw too much!
 
Was able to replace both primary and secondary TPS, they now are set to the right voltages. Bike is still backfiring above 1500 RPM and cannot go over 45 MPH, unless the bike is allowed to sit running for 30 mins before riding. After waiting it then goes up to 2500 rpm and 70 mph before it backfires. only code being thrown is P0638- Secondary Throttle control system malfunction.
 
does anyone know if this may be related to a bad crankshaft position sensor? the one i bought to replace the old one was used.
 
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