Finished a cam swap on my 05 Ultra today. Installed S&S 585 cams and went for a test ride. Ran great for about 7 miles then lost the throttle response and limped it home the last 1/2 mile. It has EFI but will not start unless you crack the throttle like a carb. Bike has 35000 miles on it, 103 ci with head work and a PCIII. From what I can find out a P0108 code is a high map sensor or the ECM. Any thoughts or ideas on where to start would be appreciated.

BBB

 

How about a different tune???

Jim

 

Are you sure the MAP sensor is connected? Induction module tightened down?

 

First thing I'd do is remove the PCIII to rule out a problem that it is causing

 

maybe IAC?

 

Did you remap it for the new cams? Could be a loose connection, bad MAP sensor or maybe the induction module needs cleaning, take the AC off and look down the throat, lotta engine fumes go thru there causing a filthy buildup.

 

You need a dyno tune for a cam swap. I'm surprised it ran at all

 

Just a few possibilities. A high MAP signal is normal usually when the throttle is at or near WOT. But I believe the ECM can detect a MAP reading that is inconsistent with the throttle position. So if there's not enough vacuum at the sensor location (engine side of the throttle plate) to match the partially closed throttle plate position it means something is wrong. There should be more of a vacuum with that throttle position. But there's not. Thus the high MAP signal error code. And limp mode. Causes could range from a throttle plate not operating properly, severe air leak, faulty sensor, throttle cable out of adjustment, an intake valve not opening (adjustable push rods?), plus other possibilities like a bad ECM, tune, etc.

 

if you don't have adjustable pushrods,,,i would think the valves are not closing all the way......if you do have adjustable,,,might want to check em....