Hi Guys, I got a few questions about IS control system in 1990 Cherokee - to be precise, in my 4L, 4wd Laredo. When I turn ignition On, a spindle in ICM extends to maximum, blocking air passage completely ( I cannot start the engine without keeping gas pedal half-down). ignition OFF, and spindle retracts back completely. Now, does somebody knows for sure, are there any engine sensors, besides of Engine Temperature Sensor, which determine ( via ICM) work of IS motor? I have checked grounds and connections, all seems to be OK. I back-probed ISC, and found when engine is working, ISC gets some strange voltage - 10,5 V. Is it right? An old Mitchel's Shop Man. If I remember, an old Mitchel's Shop Man. said it suppose to be ABOUT 12 V. Could it be a computer? I have checked all connections more generally, did not have time (and determination) to get to computer to check wire after wire. To make sure ISC motor itself is OK, I connected another I knew it is good, and it was the same. Any advise? Would really appreciate, before I dig into that mess ( did it already a few times, and I am getting a shiver just thinking I have to do it again...)
And another question: my engine has to spin for quite a while, before it start to work. I checked compression and fuel pressure - all normal, plugs and cables OK, cleaned injectors - no change. Timing belt changed last year - nonsence work, for after 200k miles, old sprockets look barely wearied, chain with no stretch. Any idea what could cause that heavy start? I read somewhere injectors from Neon fit 4L engine, Does anybody knows something it that matter? Thanks for any help.
Adam

 

Click on the link in my signature and do posts 1,3,4, and 5. No shortcuts. Then see what happens and report back.