Ok, I've looked and don't see the answers I need. Here's the situation. '98 D1 that's been running like a top. Only engine changes so far were safari snorkel install a few weeks ago which required me rotating the MAF 180 degrees to fit the intake hose. No problems for a week after driving.

Then I park my truck outside overnight for work (she's usually garaged...never been that cold), and when I get outside it's in the 20's. Starts up without issue, then low-idles for a 2-5 seconds while it figures out what's happening with the cold, then goes up to 1100-1200. Drives home no problem, but when I get there and put it in park idle shoots to 2000 rpm.

I shut her down thinking it's a fluke, but the problem is still there after a few days. I start up the truck in park, shoots to 2000 rpm...drops back down to 1100 as I reverse out and into drive. No CEL, no engine codes or pending codes on the UG. No hesitation, drives great.

It being Xmas day, everything within 30 miles is closed so I can't run out to buy carb cleaner to test for vacuum leaks. Here are my questions.

1. How much time do I have to fix this without doing damage? days? weeks?
2. Where ARE the vacuum lines? RAVE isn't very specific, though I was able to find the stepper motor
3. With the huge weather change being the only change, and no codes to go with the high idle, would I be safe to assume I can skip all the other troubleshooting steps and just have the MAF reset?

Thanks! Merry Christmas!

Troubleshooting High Idle
96 Discovery High Idle Problem...Advice Needed! - Land Rover Forums : Land Rover and Range Rover Forum

 

If it was me, I'd put the MAF back into the original position and see if the condition goes away. Can't imagine why that would have any effect(unless something came loose internally during the move), but since the problem occurred the first time you parked it in the cold after you flipped it, I would want to eliminate that possibility.

 

I'd have a look at the engine coolant sensor - if it reads very low, the ECU would send more gas and no codes (because ECU thinks it really is very cold). Mine reads ambient when vehicle has been parked, and -40F when unplugged. Shows up as coolant temp on a scanner.

IACV could use a good carb claning also.

 

Thanks for the input, I'll start digging in tomorrow. Went outside to check it out cold and took a video...sits at 2000rpm in park, then drops to 1200 when I drop into reverse. On the UG engine coolant temps stable at 123-126F throughout, intake temp sitting at 66F. TPS on the UG shows 20.8% regardless of gear selection.

Funny thing though...the MAF reads 0.15-0.16g/s in park at 2100rpm, then goes to 0.2g/s in reverse/drive and 1200rpm. I'm assuming the MAF is reading air flowing into the manifold from the intake. I'd also assume that higher rpm would be associated with higher air flow? If this is true, then I'm guessing I broke my MAF and should replace it.

Any other gauges that might help on the UG? Here's the action:
http://www.youtube.com/watch?v=HBglT...ature=youtu.be

Thanks guys! (love this place)

 

A quick thing to check (I had this issue twice) is where the throttle cable adjuster clips into the metal bracket.
My adjuster had popped out and that caused the throttle to be kept open a bit,

Let us know if that helps

 

Also a good point. BTW, 126 is too low, it needs to be warmer. You may have no thermostat, or one that is stuck open. Should come up to 180 - 195. I was making in the 180 range the other day at 50 mph in 28F.

If stuck open, and low temp, won't go to closed loop fueling when it should and mpg will suffer, plus more fuel is sent to get it to warm up.

 

Great, thanks guys. Stopping by autozone on the way home from work tomorrow to pick up some carb cleaner. Also will take a look at the throttle cable adjuster.

With regard to the engine temps, it comes up to 180-190F during daily driving. The video was with a cold engine...just on and off.

 

Ok, time for some closure. Here was the IACV when I pulled it.



Getting it off wasn't bad...remove the multiplug, ended up using 5.5mm socket to get it out. Used the same gasket as it looked fine. Cleaned it off with a bit of carb cleaner, reinstalled. Verified throttle cables were GTG. Fired up, nice...smooth...quiet idle at 1000 rpm. Left the MAF rotated the other way, though I'm going to replace it soon as the inner screen looked a bit beat up.

Thanks again

 

Your idle should only be about 6-800 I think.

There were 2 things causing my high idle.

1. make sure the throttle cable is adjusted (and mounted) properly.

2. my cruise control link to the throttle body mechanism was/is too short. Still not sure why...if I try to unscrew from the ball-endcap, it pops out before I can get enough slack. At any rate, this caused the TB to be slightly open at all times --> high idle.

 

Oh yeah, while driving it settles down to 700-800rpm. Keep forgetting to mention I'm reporting cold numbers...haven't driven the truck since Monday.