Cold Idle issues and more

[amg61]

I have done some research and am trying to learn about the stepper motor on my 96 Disco, 4.0, but i need a little help. It's still cold up here in the northeast, and when i first start my Disco in the cold, until it gets up to normal temp, the idle will fluctuate occasionally and drop down below 5K. As soon as everything is warm, i'm good to go, and the idle rests in the comfortable 7500 range and runs smooth. Today, just after I started the Disco and drove a couple of blocks, the idle dipped way down, the engine stalled and the oil gauge came on. I started right back up and it happened again. Then, I started up and kept revving the engine up to 2-3K until it warmed up. Finally, at operating temp. the idle held and I was back to normal, but I'm afraid this won't last long. So, what should I do???????

I'm assuming I should clean out the IAC/stepper motor, if I can figure out Rover Chic's picture. I think it is that triangular piece outlined in pink in box #12 in this thread: http://www.landroverworld.org/forums/showthread.php?t=584&page=1&pp=10&highlight=stepper+motor.

Remember, I have a 96 Disco I 4.0L. Is this thing hard to get out and clean? Do I disconnect my neg. terminal first??? I can't tell if those are hex or torx nuts holding it on. Anyway, any advice would be great. In fact, maybe it is another issue all together, but I kind if need to fix it tonight, or just warm the car up early tomorrow before i go out and then fix it later in the day.

On a separate note or two. My glove box door won't stay closed shut. The latch spring stays open too easy and the door falls down. Any ideas??

And lastly, occasionally, I have REAL difficulty turning the key to start the car. Sometimes i have to flip the key over 180 degrees, or push it IN real hard, into the steering column first. and this is with the wheels straight ahead. Any ideas? This happens every once in a while.


THANKS

 

[amg61]

Gee, hate to respond to my own question with another question but then i saw this thread: http://www.landroverworld.org/forums/showthread.php?t=2133&highlight=idle

and the IAC in the picture in frame 5, is actually IN FRONT of the triangular piece that was circled in Rover Chic's thread. So, which is it. It seems like the thing circled in Rover Chic's thread is actually the TPS and the IAC is in front of that. If so, how do I get out the IAC and can i clean it with brake cleaner???? Or, maybe I should be doing something totally different to fix this problem....


Thanks again !!!!

 

[Moose]

Those are classic IAC a/k/a Stepper Motor symptoms.

Brake cleaner is fine. The Stepper has a wiring harness attached to it, you should disconnect that, and then use a 5.5mm nut driver to remove the little bolt that holds it into place.

What is highlighted in post 12 of this thread is the Throttle Position Sensor, and you're right -- the other part on there, which looks like it sits diagonally, is the Stepper. It's directly behind that breather hose that runs from the crankcase to the intake plenum (that breather hose, BTW, is the best way to get SeaFoam into the intake).

Good luck!

 

[amg61]

Moose, I'm so glad you replied. Thanks.

Just to let you know, I did figure out how to get the IAC off, first taking that breather hose off the plenum. The IAC did have some carbon build-up and i cleaned it well with carb cleaner, along with shooting some into the hole where the IAC plunger fits into the engine area. Well, I reconnected it all, and STILL, when the car is cold, it just wanted to SHUT down. I had to keep revving until the car warmed up in order to allow it to idle on its own. All that cleaning did not fix my cold idle blues, bummer!!!! Was there something else I should have cleaned out at the same time, while I had the IAC off, or do I need to buy another IAC? It's interesting that my Disco I 4.0 idles great once it is warmed up, so could the problem be elsewhere?

I do have some seafoam, but I don't know if that would really make a difference with this specific problem, and I don't want to start throwing codes. As for that breather tube, if I were to use seafoam, then I just disconnect it from the plenum and let it suck the seafoam down into the crankcase??? maybe another time. I HAVE to get this cold idle probelm fixed FIRST !!! Any other ideas????

Thanks.

 

[amg61]

Oops. Regarding the seafoam, i pour it ino the intake plenum, not the crankcase, right?? Anyway, let's forget about seafoam for now, unless it will fix my cold idle problem.

 

[Moose]

EDIT: Beat me to it

It's the opposite. Disconnect at the crankcase end and let the fluid get sucked into the plenum. Do it slowly so the motor doesn't die on you. Let it sit for a while and enjoy the smokescreen!


Try that and let us know if you're still having problems.

 

[amg61]

And what about my cold idle problems???????? Somewhere I read that I should have let the IAC sit out and dry for about an hour after I cleaned it, but I read that after i cleaned and manually dried it and then put it back in place. Oh well. Would that really matter??? This cold ONLY low idle, stall, problem is really ticking me off. Any other ideas???

 

[amg61]

Try that and let us know if you're still having problems.

Oops again!! Didn't see that quote above. Do you really think I should seafoam it before I look into anything else???? And would that drying the IAC for an hour suggestion have made any difference??

Thanks!!!

 

[amg61]

OK, i love replying to my own post. Well, i did the seafoam thing along with the stepper motor cleaning and no change. I know the stepper motor in the 4.0L usually doesn't crap out as often as in the 3.9L and i certainly wasn't going to pay $200 from the stealership to find out. HOWEVER, through this site and the web, i found this part at Napa:

http://www.napaonline.com/MasterPag...mber=21856&Description=Idle+Air+Control+Valve

It's Napa part: CRB21856 and is the stepper motor for the 4.0L, NOT the 3.9L.
Guess what? It was only $38.

So, I replaced my stepper motor with this one, and Wow, what a difference. Idles perfectly!!!

So far, so good.

One more thing. On various other posts, people mention that when you change the stepper motor, you have to have the dealer or a mechanic adjust the idle. Well, the paper instructions included with the new stepper motor mention what to do for a Buick, Pontiac, or anyone with a TBI. I tried those instructions and the idle is FINE.

Hope this lasts.....

 

[joey]

glad to hear things are going well, and thanks for the IAC Napa info...