Notices
911 Forum 1964-1989
Sponsored by:
Sponsored by: Intercity Lines, LLC

Reference Sensor gap

Thread Tools
 
Search this Thread
 
Old 02-10-2011, 10:13 PM
  #31  
dshepp806
Rennlist Member
 
dshepp806's Avatar
 
Join Date: Nov 2006
Location: Middle GA.
Posts: 2,958
Likes: 0
Received 1 Like on 1 Post
Default

ohm those grounds....

Cool, Rusnak.....
Old 02-10-2011, 10:30 PM
  #32  
User 4221
Addict
Rennlist Member
 
User 4221's Avatar
 
Join Date: Jun 2001
Posts: 7,031
Received 47 Likes on 29 Posts
Default

I would check the grounds that connect to the intake runners since you had the engine out and needed to remove them.
Old 02-11-2011, 12:31 AM
  #33  
rusnak
I haddah Google dat
Rennlist Member
Thread Starter
 
rusnak's Avatar
 
Join Date: Nov 2008
Location: Fresno, CA
Posts: 11,501
Likes: 0
Received 4 Likes on 4 Posts
Default

Originally Posted by Lorenfb
"Could there be onboard memory processing that causes this?"

Remember, the fuel pump relay is not only energized once the speed/ref signal occurs,
but also when the #50 from the ignition switch/starter solenoid applies power to pin 4
of the DME ECM. Any signal noise or a poor ground on pin 4 will cause the fuel pump
relay to energize, thus running the fuel pump. A voltage as low as 4 volts on pin 4
will cause the fuel pump to 'run'.
I posted about that previously, because I asked myself the same question. I had the pressure gauge hooked up, and the fuel pump was putting out 37psi when the key was turned on. I cleaned the dme grounds practically to the molecular level, and cut the zip ties and separated the wires leading to the ignition switch, looking for a stray short or loose wire. I also disconnected the remote starter button, and tried just the switch in the dash - no change.

I had previously "fooled" the DME by pulsing the ref sensor against the fender, which is why I'm wondering if the stored logic was in run mode, not shut down mode. The car was running with no signal whatsoever from the reference sensor at the time power was last cut at the switch. Surely not all processing is done in real time continuously. That would be too much. There must be memory of some sort in the dme brain.

It's an interesting possibility anyway.



Quick Reply: Reference Sensor gap



All times are GMT -3. The time now is 04:45 AM.