I am still chasing my idling problem. My truck seems to idle fine in drive but in park it surges. I was watching the injector pulse width when it starts to surge and it sometimes jumps from 1.2ms to 30ms. I shut the engine off key in run and watch the pulse width and it will do the same thing. Has anyone ever seen this? Bad ECM maybe? What am I missing?
ECM question
- Thread starter sy2756
- Start date
leroy
Donating Member
For the surge, check for vacuum leaks, check timing, and fuel pressure.
You can also run down the list here: http://www.syty.org/old/d&e-surgechuggle.html
Jim
You can also run down the list here: http://www.syty.org/old/d&e-surgechuggle.html
Jim
Thanks for the replys. What is the difference between the truck idleing in park vs drive? It seems to idle fine in drive.
I have replaced all of my ingintion components, checked my timing.
I have also checked for vacuum leaks via the bike tube trick, but here is where I have another question. My throttle body shaft leaks pretty bad using the compressed air but if you spray starting fluid or propane around it the idle does not change. These are both ways of checking for vacuum leaks suggested on this board so which one do I believe?
I have replaced all of my ingintion components, checked my timing.
I have also checked for vacuum leaks via the bike tube trick, but here is where I have another question. My throttle body shaft leaks pretty bad using the compressed air but if you spray starting fluid or propane around it the idle does not change. These are both ways of checking for vacuum leaks suggested on this board so which one do I believe?
I have pulled and cleaned the IAC and passages, looked fairly clean to start with. Put it all back together same deal. IAC counts are between 30 and 40 in park and a little higher in drive. Adjusted the throttle stop so they were about 20 in park(??). Same problem.
I also checked my fuel pressure, 42 psi with the vac line disconected.
Is the TB shaft repairable by a machine shop? Looks like its not a servicable part. I'm guessing a replacement would be about $200-300.
Thats a lot of money for something that may or may not fix this problem.
I also don't understand why this would cause a problem in park/nuetral and not in drive.
I also checked my fuel pressure, 42 psi with the vac line disconected.
Is the TB shaft repairable by a machine shop? Looks like its not a servicable part. I'm guessing a replacement would be about $200-300.
Thats a lot of money for something that may or may not fix this problem.
I also don't understand why this would cause a problem in park/nuetral and not in drive.