Update - On Knocking problem but would this cause....

[channer]

I think I might have solved my knocking problem thanks to James McDonald today

I've got about 1/8-1/4" play in my crank pulley/hub. I'll have to take a closer look tonite/weekend but James thought it could be a worn crank key, worn slot on the pulley/hub or a worn slot in the crank.

This poses another questions regarding my hestitation/stumbling at highway speeds (60-70 mph). Could this much play in the pulley/hub cause the crank sensor to send bad signals to the ECM. The hestitation/stumble only happens (that I notice) at hi-way speeds and gets worse the longer I drive until the car no longer runs... after a cool down of 30 minutes, it starts and runs for a little while until it dies again. I've check and/or replaced the coil/module, MAF & fuel pump but hesitation/stumble is still there!!

What are the chances that bad crank signals might be causing the hesitation problem???


dave

 

[Black Car]

Dave,
Do you have access to direct scan?
Do you have an aftermarket tach?
If the interuper rings move 1/16"-1/8" it can shut off the rpm signal to the computer. The car will act like it has shut off or a very bad miss.
The aftermarket tach will go to zero for the time that the interuper ring is out of position.
The DS will show NO rpm and will catch it better than the tach.

This can also happen if the harmonic balance bolt works loose.

Gary

 

[channer]

Hi Gary...

No tach but I do have TLINK. I have notice the RPMs going crazy but mostly at idle... I thought it was the TLINK giving false readings because the scanmaster readings looked normal.

I don't remember looking at the RPMs when I'm at highway speeds. I'll check my backup files on some old recordings.

Do you thing the TLINK as the same way as the DS?

thanks... dave

ps: The temp sensor also jumps all over the place on the TLINK... what would this do to the ECM!!!!

 

[KWIKR 1]

Originally posted by Black Car
Dave,
Do you have access to direct scan?
Do you have an aftermarket tach?
If the interuper rings move 1/16"-1/8" it can shut off the rpm signal to the computer. The car will act like it has shut off or a very bad miss.
The aftermarket tach will go to zero for the time that the interuper ring is out of position.
The DS will show NO rpm and will catch it better than the tach.

This can also happen if the harmonic balance bolt works loose.

Gary

hummm! I had a very bad miss problem this season and was unable to find it . And it sounds exactly like you describe . Almost like someone shut the ignition off for a slip second at mid track . and also ended up with a slight knock on my last run .I'll have to check that . Thanks.

 

[Marty]

RPM SIGNAL LOSS ?

I HAVE A SIMILAR PROBLEM. WHENEVER BOOST IS OVER 10 -12 PSI THE CAR BACKFIRES IN THE INTAKE, STUMBLES, ENGINE KNOCK. THE DS SHOWS LOSS OF SENSOR SIGNAL FROM ALL SENSORS TEMPORARILY AT TIME OF STUMBLE AND MY REV LIMITER ( ARMSTRONG CHIP) FLASHES ON AND OFF BEFORE THE RPM REACHED. IS THE ECM SEEING LOSS OF RPM SIGNAL ?

I WAS ALSO WONDERING , SINCE THE CRAK SENSOR IS NOT ADJUSTABLE TO PISTON POSITION, HOW DOES THE ECM USE THE CRANK SENSOR OTHER THAN RPM? OR DOES IT? DOESN'T THE ECM USE CRANK SIGNAL FOR IGN. FIRING SINCE IT HAS THE THREE SLOTS? CAM SENSOR HAS ONE ON OFF POSITION AND IS USED FOR FUEL INJECTION TIMING. SO HOW DO WE KNOW THAT THE CRANK POSITION SENSOR IS IN THE RIGHT POSITION TO THE PISTON?

 

[KWIKR 1]

The postion of the balancer to the crank is what determines position to the piston .The balancer can only go one one way. The sensor just reads the balancer interuper ring at that prdetermined position.

 

[Marty]

KWIKR 1,
I UNDERSTAND THAT THE BALANCER GOES ON IN ONLY ONE POSITION. THE CRANK SENSOR POSITION ON THE ENGINE BLOCK MIGHT NOT BE IN SINK WITH THE PISTON AT TOP DEAD CENTER. SUPPOSE YOU MOVED IT CLOCKWISE OR COUNTER CLOCKWISE, UNTIL THE INTERUPTOR IN THE HUB REACHED THAT POINT THE PISTON MIGHT BE BEFORE OR PAST TDC. SORT OF LIKE FINDING TDC AND THEN ADJUSTING YOUR TIMING MARK TO 0 DEG. BUT WE CAN'T ADJUST OUR CRANK SENSOR CW OR CCW TO 0 DEG.