High idle speed?
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Joined: Jul 2004
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High idle speed?
I have a 1997 Mazda B4000 4x4 truck, with 90K miles on it. After putting around 300 miles on it this weekend, I realized that the truck was idling higher than it used to (1500 to 2000 rpm). However, when you come to a stop, the rpms slowly step down to about 800 rpm (which is what it used to idle at). Does anyone have something similar happen, or any ideas what could be causing this? Other than the intermittent 4 wheel drive problem listed on another thread, I don't appear to be having any other problems. Actually, that's not true. Having some issues with the temperature gauge, but sounds like that may be standard with these trucks. The gauge tends to read low, and when I turn off the truck, it stays at whatever level it was reading while running (both oil temp and voltage level go to zero when off). Is this normal, or is the sending unit most likely toast?
Thanks for the help,
Matt
Thanks for the help,
Matt
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Joined: Nov 2003
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my '92 xlt 3.0 with 115k miles was doing that since new (I'm original owner) and last year I changed the idle air control valve (IAC) and that seemed to help (although a good cleaning of the old one probably would have sufficed and saved me money). I changed both O2 sensors a few months ago and I have not had the problem as consistently as I used to. It does it very very rarely now and I think that may have been a great contributor to the problem. May be worth a try.. 
Posting Guru
Joined: Nov 2003
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From: California Desert
There is a TSB concerning this. It is a faulty connection in the TPS (throttle position sensor) wiring harness. You can get a service kit from Ford I think...but it might be a little pricey. I just clean every intake sensor and connection every 3 months or so and I don't have the problem anymore. Actually...I haven't had to touch anything past the MAF in a while...maybe one of the cleanings fixed it? Who knows...but cleaning the TPS and the IAC would definitely help as XLTDAWG suggested.
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Joined: Aug 2004
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From: Central Texas
Howdy Maticuno
My 99 Ranger ildes at near 1200 and it is annoying to say the least. I'd like to know where to find out more about the TSB you wrote about. Your post is very interesting to me.
Big Jim
Big Jim
Last edited by Big Jim M; Aug 24, 2004 at 09:46 AM. Reason: bad spelling...
Posting Guru
Joined: Nov 2003
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From: California Desert
Here's the thread with the TSB info on it: https://www.ford-trucks.com/forums/s...d.php?t=236750
Senior User
Joined: Aug 2004
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From: Central Texas
I think it is FIXED!!!
Here is an update. In the past few weeks I have changed out for NEW the IAS and the TPS... With absolutely no different idle results. Then I read the reply's here and thought to myself that a new thermostat and sending unit could not hurt and would be pretty cheap too.
So today down to the parts place I went and came back with a gal of prestone and the two parts described above.
I installed the parts and hosed all of the greenish fluid off of the engine and driveway. When I first started the engine it popped and cracked some from all the hoseing I did to it I guess. Then it went to about 800 after a short around the block drive. I have owned it about 9 months and have not seen 800 EVER!
The sending unit has TWO wires coming from it instead of the normal (to me) one wire most seem to have. Maybe one goes to the computer and the other is to the temp gauge on the dash... and it was telling a lie to the computer! I don't care if it keeps on working.
Big Jim
