| Author | Message | ||
     gregory gibbard (Fj40) New Member Username: Fj40 Post Number: 15 Registered: 01-2004 |
Can someone offer some help hopefully clarity on the stepper motor? My truck is idling unusually high 1100rpm (when in Drive) and 1400-1600rpm (when in Park or Neutral). I just popped in a new Throttle Position Sensor (TPS) today and attempted to clean the stepper motor while I was figiting with the TPS. When I started the truck up, boom it was racing at 1800rpm and gradually worked its way back down to 1400-1500 rpm at idle. This wasn't happening before. I've been trying to hunt down the mystery problem when I have to decel from anywhere around 65-70mph down to just above 50mph and then the truck runs horrible for a while, or until I slow down under 50mph and it down shifts. I've already replaced the VSS and that hasn't helped. I was planning on using some Seafoam Deep Creep in intake, but am now hesitant as I am a bit leary on creating a potential for multiple problems before I figure out this new issue. Biggest question is on the stepper motor. What exactly needs to get cleaned? Is it the push rod portion or is there a way to get at it the actual motor. I just saw the cost of a new one ($200.00) and I would rather prefer to just clean the one that I have. There was quite a bit of gunk on the push rod, which has been unscrewed and cleaned. Is there anything else? I am definitely at a loss with the crazy idle. I have yet to put the old TPS back in, that is probably my next step. | ||
| Jaime Crusellas (Jaime) Senior Member Username: Jaime Post Number: 303 Registered: 05-2003 |
The conical tip should be cleaned so that it can seal properly, and the shaft should be cleaned so that it noes not bind when the motor turns (it will turn in choppy little steps though). The motor is sealed, so you can't clean it. If after cleaning, it still runs lousy, give it at few cycles of starting the car, driving for 10 minutes, and shutting down the ignition. Sometimes this helps get things 'seated'. If this fails, you can get a good stepper motor made by Britparts (the largest LandRover part manufacturer) from either Atlantic British or Nathan at discoutbritishparts.com for waaaaay less than $200. I went through a similar ordeal as you, and the new part did the trick. | ||
| ron morgan (Rpm2429) New Member Username: Rpm2429 Post Number: 28 Registered: 08-2003 |
I agree, I spray the heck out of it with solvent and remember to clean the area where it seats against the throttle housing/mounting area, so you have a thight seal. My truck runs like s--t for about a day, then is fine. | ||
| Brian Brown (Rtiqulatendisco) Member Username: Rtiqulatendisco Post Number: 56 Registered: 01-2004 |
I had the same problem... check your vacuum hose at the rear of the plenum. | ||
| gregory gibbard (Fj40) New Member Username: Fj40 Post Number: 16 Registered: 01-2004 |
thanks guys. we took the stepper motor back out and cleaned the heck out of it and the area that it seats into. Then I took the breather hoses off and cleaned all the built up gunk that was in those. Put everything back together again and started it up. It ran pretty good, idle was where it needed to be about 800-900rpm. I was thinking how wonderful it was, then I turned the truck off and had to take care of few things before heading back into town. When I started the truck up, it was revving high again about 1800rpm. I drove the truck to town and figured we'd give it a day to seat back in and see what's happening. So far, it is still revving high. We've checked almost all the lines. We're planning on doing some vacuum test sometime this week. Does anyone have any other ideas? I do have a couple of questions on the stepper motor. When cleaning it, I would imagine that the conical tip needs to be screwed all the way back onto threaded shaft. Does anyone know if this is correct? I've also read some other threads about using some ($25)GM steppers. Does anyone know of an equivalent for a '99D1? | ||
| Jaime Crusellas (Jaime) Senior Member Username: Jaime Post Number: 306 Registered: 05-2003 |
Gregory, I bought one of the $25 motors, and it was a joke, it wasn't even a close fit. I have a 97 disco, I don't know if its different for a 99. | ||
| gregory gibbard (Fj40) New Member Username: Fj40 Post Number: 17 Registered: 01-2004 |
I was wondering about those $25 miracle parts. Great for GM users, bad for us. I highly doubt it would fit any better for a 99. Can you drop a chevy 350 into a disco? (just an idea. they've been doing that with Toyota's for years. not that I want that headache.) I just got a response back a little while ago from Nathan at Discount British Parts with a much better price than anywhere else. I think I'll be following up with him tomorrow. | ||
| Blake Monchilovich (Azblake) Member Username: Azblake Post Number: 139 Registered: 02-2003 |
I got the IAC valve from NAPA for around $30. No problems in 2+ years, just normal cleaning. | ||
| gregory gibbard (Fj40) New Member Username: Fj40 Post Number: 18 Registered: 01-2004 |
Blake, what kind of IAC valve was it that you ordered? For a rover, or is it the GM equivalent? I still havent' bit the bullet yet. $30 is much better than $130. What year Disco do you have? | ||
| Blake Monchilovich (Azblake) Member Username: Azblake Post Number: 145 Registered: 02-2003 |
'94. Ordered at the counter and it came up as a Borg Warner 21738. Same fitting and stroke. Can't remember if it was referenced to a Disco or I got it off some CB list. I think the location and style changed the following year. Genuine parts seem like a ripoff, especially as most ISO suppliers have to second source as part of the qualification. | ||
| gregory gibbard (Fj40) New Member Username: Fj40 Post Number: 19 Registered: 01-2004 |
thanks Blake. I appreciate all the info. I'll check it out and see what I can find. | ||
| Steve Andrews (Sillybus) Senior Member Username: Sillybus Post Number: 440 Registered: 08-2002 |
Greg - While I played with getting my 99 D1's idle straight, I removed the IAC, unscrewed it a few turns counter-clockwise and put it back in. I left the multi-plug off. Play with it a bit and you can get the idle in a safer range until a proper repair/diagnosis can be done. | ||
| gregory gibbard (Fj40) New Member Username: Fj40 Post Number: 20 Registered: 01-2004 |
Thanks Steve. I've got a IAC that is supposed to show up today. Hopefully that takes care of the issue. So, I'll definitely try doing some adjustments until that shows up. | ||
| Sandy Grice (Apg) Member Username: Apg Post Number: 44 Registered: 02-2003 |
I have yet to find an off-the-shelf stepper motor from NAPA, GM or anywhere that actually fits to say nothing of working. Mind you, '95 an earlier models have one type, the '96 and later ones with OBD-II use a different one. I perrused various parts found on several Rover sites but I've yet to find an IAC that works. My '96 Disco was doing the same thing several months ago. Cleaned the hell out of the stepper motor and housing (for the fourth or fifth time) and so far (touch wood) all is well. Cheers | ||
| gregory gibbard (Fj40) New Member Username: Fj40 Post Number: 21 Registered: 01-2004 |
I received my new stepper motor on Friday afternoon and had to try it, since I was off on a 600 mile trip on Saturday. I put it in and there was no change with the idle. It was still high at about 1700rpm. I let the vehicle run for a while, turned it off and then restarted it again and still no change. I decided to try my old Throttle Position Sensor again, which was the only other thing in the equation that had changed. As soon as I turned the engine over, it was back running as always. Idling about 800-900rpm. Great I thought. This fixes my idle problem, but when we took off for our trip on Saturday, my old problem on the highway was apparent. This is the studdering when having to suddenly slow down at highway speeds but only when I don't drop below 50mph. I couldn't duplicate this with the new TPS in place all week and I tried almost everyday. I am not sure if that was due to the high idle. Thankfully, the truck only stubbled once on the entire trip. We're not sure if the TPS was bad or not, so it is going back and I am supposed to be getting a new one. |
