By Redsrover (Redsrover) on Wednesday, September 26, 2001 - 03:22 pm: Edit

Is there a simple adjustment to reduce the idle rpm speed from 900 to 700 where it is supposed to be? The engine runs like a top, perfect except for the extra high idle.

Thanks

Red

By danno on Wednesday, September 26, 2001 - 03:26 pm: Edit

the idle is set from that factory and covered by some plug (in the LR workshop manual). check to see if the throttle cable has the proper amount of slack in it and that the throttle butterfly fully closes.

By Redsrover (Redsrover) on Wednesday, September 26, 2001 - 03:33 pm: Edit

That's the base idle under the plug you're referring to. Mine's been reset (no plug) so I suppose an allen wrench may do the trick on the idle. Who knows?

Red

By Danno on Wednesday, September 26, 2001 - 03:38 pm: Edit

if everything is working properly, i say go for it.

By Robert Mann (Oldscout) on Wednesday, September 26, 2001 - 03:45 pm: Edit

I bet you have a vaccum leak.

By Mike Beiergrohslein (400mcs) on Wednesday, September 26, 2001 - 04:03 pm: Edit

Mine did the same there was a hole in the tube (on the right side of the air intake) which the engine compensated for by a high idle, required resetting by LR dealer

By Discosaurus (Discosaurus) on Thursday, September 27, 2001 - 05:35 am: Edit

The normal idle speed is governed by the ECU and really can't be adjusted without screwing up other "things".

You probably have another issue (air leak, open loop O2 sensor, stepper motor).

How old is your truck ? Amy recent MIL's ??

keith
discosaurus

By Redsrover (Redsrover) on Thursday, September 27, 2001 - 05:49 am: Edit

Well, its a 1997 model and I just had an o2 sensor replaced after it went back (was cracked off roading). Explain the "open loop" idea please.

Red

By Robert Mann (Oldscout) on Thursday, September 27, 2001 - 06:04 am: Edit

Open loop:
When the engine is cold or the ecu is not getting the right spec from all of the sensors it will go into open loop and use a set of parameters that will run the engine close too but not at perfect tune. Open loop after warm up will trigger the CEL.

By Redsrover (Redsrover) on Thursday, September 27, 2001 - 10:45 am: Edit

So if I have this "open loop" situation you describe, I should get the CEL illuminated once the engine is warm? The CEL will confirm this?

By Robert Mann (Oldscout) on Thursday, September 27, 2001 - 11:05 am: Edit

Open loop is just one of a hundred things that will trigger the CEL. Open loop is just the output of a ECU that is not getting the info for its mapping in the Eprom. Think of open loop as a get you home mode when things are not right.

By jpitman on Sunday, October 07, 2001 - 05:55 am: Edit

sounds like an air leak. i HAD THIS RECENTLY, AND AT SERVICE DEALER found an oil leak on inlet manifold gasket. Fixed this - high and erratic idle went away, almost. There is a Service Bulletin on this, and a change to routing of the Purge line to the inlet plenum. I can dig up the number if you want. Somebody sent me the detail pages of it. Dont play with the base idle adjustment without noting where it started (ie no of turns out from closed).
JP