Re: 85' 5KCST Check Engine Light

["Sherry & Chuck Clark" <clark@rmi.net>]

Dave,

      I would suspect that your problem is related to the knock 
sensor. I had this same problem on my '87 5TQ. I could usually hit 
full boost at 1.3 bar and then I  would get a serious drop in power 
when the light illuminated. The computer is retarding ignition some 3 
degrees or so every time the light lights up. Check your fault codes 
after you have made the light come on and before shutting the engine 
off! Can't remember the specific code but this was my problem. Also, 
make sure that you have only a qualified mechanic put the new knock 
sensor in as it needs to be torqued to the block with the exact 
number of ft/lbs. Something like 12 ft/lbs. Anything less or torque 
it too tight and the light will continue to flash. 

         I tried using  93 octane gas(unavailabe here in 
Colorado-paid big bucks for 1 tank) but to no avail.

         HTH
             Chad Clark