Hey everyone,
I am at a loss with what would cause my 1996 D1 with the 4.0 GEMS engine to go to 2K RPM's on every start whether it's cold or hot. Back tracking my steps and pinning it down to about when it started happening would have to be right after I cleaned the throttle body and linkage. I cleaned the TB because I was getting some dead spots when accelerating. Wound up being the TP sensor. I replaced the TP sensor, IAC valve, re-cleaned TB and checked vacuum system. It only has these high RPM's at start then it drops slowly down to about 650-750 and idles fairly well. I am about to remove the Plenum/TB to make sure there isn't something I just cant see but I figured I would present my problem to fresh minds. Any suggestions will be appreciated.

 

normal

 

Sounds like a iacv issue. Iacv is supposed to close at startup if yours ismdirty it might notnclose all the way and then open up in reference to where it thinks is closed. And then correct itself after startup, my guess

 

Hey spence he said he replaced the IACV so it shouldn't be dirty. Gunny, when you replaced everything did you have all your values reset with testbook or have you just let it reset over time? If you did not have it reset I would suggest finding an indie with testbook (not the aftermarket software but the real deal) and have them reset everything. I would advise you to not go to a LR dealership unless you want to pay a ridiculous amount for 2 minutes of work. Good luck.

 

When you say hot, do you mean the engine is fully warmed up? If you drive it 10 miles, turn it off, restart it immediately, does it idle at 2000 rpm?

 

I will pull the new IAC valve and check it out to make sure there isn't any build up on the seat. If I don't go to a LR dealer to reset with textbook, then would any garage have it? And yes, when I said it goes to 2K at every start up cold or hot. I meant cold and fully warmed up. Thanks for all the help so far. I'll keep you posted with what I find.

 

Also, how long does it sit at 2k upon startup? 5 sec., 30sec.? at cold this may be a bit high but they do rev up to around 1.2k for a few seconds then drop slowly and steadily to 700 ish( they should anyway). At hot it should go up to between 700 to 1k at the most and drop right away.

Is the IACV you replaced brand spankin' new or was it a used unit? And you are right in checking the seat in the plenum for the plunger. Definitely check the seat around the butterfly valve too.. they can gunk up pretty bad and let air past at idle which of course gives you higher idle or even a wandering idle at times.

good luck!

 

Yea if not iacv defiantly ecu.

 

yeah if its a split second to 2k rpm that is normal