HT4100 4.1, 4.5, 4.9 Discussion, Cannot getg into E.6.3 ISC Motor in Cadillac Engine Discussion; I cannot get into the E.6.3. ISC Motor Diagnostic to check the ISC Minimum. Can anyone help?
Got a 88 ...
Yes, I need to check the ISC settings. I got a new one and it need to be set. With E.6.3 you can retract the minimum air screw to its minimum tocheck if it's touching the throttle. I cannot check that. Without checking that I cannot solve my problem. Once the car is warm it has a idling problem, its shaking when I accelerate. Sometimes its even shaking when its in PARK. I replaced the sparkplugs, all wires are fine, Cat should be fine (I got good values on that) Maybe the ECM could be the problem?
Automobile(s): 1988 Allante' (sold), 1984 Eldorado, 84 Sedan DeVille
Re: Cannot getg into E.6.3 ISC Motor
You need to read the section on understanding how to enter diagnostics. Moving from section 70 to the test procedeures is what I assume you dont understand. Once "ECM" is displayed at the end of the code search you need to press hi fan which ,to the computer, is answering yes. By factory manual do you mean the GM manual, not Haynes or Chilton. The on board diagnostics are capable of not only supplying fault codes but showing engine RPM, timing, coolant temp and many other parameters once you are familiar with navigating thru whats available.
I know the diagnostic and it's function. That's not the problem. The GM manual says after 70 appears press HIGH and then ECON to get to E6.3.. After HIGH it shows E9.5 on display (which is good) but then I push ECON to get to E6.3 and nothing happens. I can't get to E6.3...
any other suggestions on my shaking problem. It's not a hard shaking but it's not the smooth drive of a Cadillac I'm used to. Thanks for any suggestions
OK, well, first of all, the ISC is not causing your problem. It does not control anything other than idle speed. Here's what I'd check, given your misfire when warm:
1. Have you replaced the cap and rotor? These might be worn. Cheap to replace and eliminate.
2. Check the EGR valve. If this is sticking open, it will cause your drivability issues. Misfiring, shaking at idle. Push up on the underside of the diaphram. Make sure it's not sticking.
Thanks for your reply and help. I've replaced sparks, rotor, cap and EGR valve. It works very much better. But still when it's warm it shakes a little while acceleration but less than before. I thought maybe the fuel injector filter might be clogged. any ohter ideas?