hello my name is Charles i stumbled upon this site seems to have alot of useful info. i have a 2000 Chevy blazer 4.3l auto 2wd i replaced the motor 3 years ago. recenlty within 2 months iv been getting a code p0740 tcc malfunction. iv replaced the vss, etc, and i had a code for 02 sensor i replaced also. stil lget the code back for the tcc when i accelerate over 50 mph. runs great otherwise. well today while at the light my speedo was jumping from 0-10 mph i wasn't moving so im like hmm another clue.... and a noise began yesterday where the fuel lines go into the upper intake along with the wires in the middle its like a steady rattle type noise. like something is loose inside the intake itself. i was hopping that the speedo and tcc problems are related to, maybe the ignition switch? for the noise im clueless hate to have to rebuild this motor now.

any input is much appreciated. thanks!


tcc light p0740 replaced, vss , ects. down stream 02 sensor.
spedometer fluctuates at stop light while in gear. (ignition switch)??
grinding noise under hood (distributor)?? or injector?

 

Have you checked the PCM?
The PCM monitors the throttle position voltage, the vehicle speed and other inputs in order to determine when to energize the TCC solenoid valve.

 

no i have not checked the pcm. any idea how to? check power to it or ?

 

 

my setup is completly different as the ecm is under the hood with 4 plugs...

 

Yes so is mine, but the point still holds about checking all the grounds and connections.

 

ok i scanned it today i had 2 codes for p0420 the tcc codes are not present now i pulled distributor to check noise all good there i look down thru tb and see where my spider lines are leakin and cleanin out the carbon on the driver side cylinder dont wanna put in a new spider injection system the updated one until i find out what this noise is. its coming from the electrical connector that plugs into the spider unit above intake could the injector be making that metal noise? i want to know if im gonna have to put in another motor...

 

ok today i bit the bullet stripped down timing cover removed balance shaft pulley thru on new chain and gear cause of some slack all together and still have this damn noise....