high Idle speed problem.......
Thread Starter
|
Freshman User
Joined: Sep 2004
Posts: 34
Likes: 0
high Idle speed problem.......
1998 Ranger 3.0 eng
my idle speed will not drop down during deceleration right away.
will hover at 2000 maybe more, then drop. problem is intermittant.
not sure what to check for.
anybody have any advice?
my idle speed will not drop down during deceleration right away.
will hover at 2000 maybe more, then drop. problem is intermittant.
not sure what to check for.
anybody have any advice?
Post Fiend
Joined: Jan 2003
Posts: 9,748
Likes: 16
From: Connecticut
First check and make sure there are no upper intake vacuum leaks, check the hoses and connections, and make sure the EGR and PCV systems are all secure, too.
Next I'd suspect a faulty Idle Air Control valve (IAC).
There is also a TSB related to this concern which has to do with reflashing the computer. I'm not sure which engine it apllies to, but it's worth noting:
Next I'd suspect a faulty Idle Air Control valve (IAC).
There is also a TSB related to this concern which has to do with reflashing the computer. I'm not sure which engine it apllies to, but it's worth noting:
Article No. 98-26-8
LIGHT TRUCK: 1998-99 RANGER
CALIBRATION:
8-49A-R06, 8-49B-R10, 8-49S-R10, 8-49T-R06, 9B1M-AA-A, 9B1M-AB-A, 9B1M-AC-A, 9B1M-BA-B, 9B1M-BB-B
WARNING: THIS MODIFICATION IS AUTHORIZED ONLY FOR THE LISTED ENGINE. PERFORMING THIS MODIFICATION ON OTHER ENGINE CALIBRATIONS IS UNAUTHORIZED AND COULD CREATE LIABILITY UNDER APPLICABLE FEDERAL OR LOCAL LAWS.
ISSUE:
The Malfunction Indicator Lamp (MIL) may illuminate and Diagnostic Trouble Code (DTC) P0320 may be stored in memory on some vehicles. There may also be a high idle rpm (1300-2000) on closed throttle deceleration in Neutral or clutch depressed. This may be caused by the Powertrain Control Module (PCM) calibration.
ACTION:
Reprogram the PCM to latest calibration level. This more robust calibration reduces deceleration air flow and reduces the possibility of high rpm with high limit hardware. In addition, the calibration error is fixed to reduce the possibility of unique driver action causing a false P0320 MIL code.
LIGHT TRUCK: 1998-99 RANGER
CALIBRATION:
8-49A-R06, 8-49B-R10, 8-49S-R10, 8-49T-R06, 9B1M-AA-A, 9B1M-AB-A, 9B1M-AC-A, 9B1M-BA-B, 9B1M-BB-B
WARNING: THIS MODIFICATION IS AUTHORIZED ONLY FOR THE LISTED ENGINE. PERFORMING THIS MODIFICATION ON OTHER ENGINE CALIBRATIONS IS UNAUTHORIZED AND COULD CREATE LIABILITY UNDER APPLICABLE FEDERAL OR LOCAL LAWS.
ISSUE:
The Malfunction Indicator Lamp (MIL) may illuminate and Diagnostic Trouble Code (DTC) P0320 may be stored in memory on some vehicles. There may also be a high idle rpm (1300-2000) on closed throttle deceleration in Neutral or clutch depressed. This may be caused by the Powertrain Control Module (PCM) calibration.
ACTION:
Reprogram the PCM to latest calibration level. This more robust calibration reduces deceleration air flow and reduces the possibility of high rpm with high limit hardware. In addition, the calibration error is fixed to reduce the possibility of unique driver action causing a false P0320 MIL code.
Mountain Pass
Joined: Mar 2004
Posts: 249
Likes: 0
From: Santee, CA
I've had the exact same problem since I bought my '99 last April. The first thing I replaced was the IAC, followed by the throttle body, and eventually the MAF (Of course I swapped the latter two for performance units). Ford ran my VIN and told me there were no recalls and only one TSB, siting that there was a potential chafing issue on the wiring harness below the driver's seat on the underside of the truck. They told me that ther were no newer flash updates for the ECU, as well. My truck is in (an independant) shop today to have the PS pump replaced, and they're trying to help me figure out the idle, too. If they can't figure out what's wrong it's going to Ford, and it won't leave 'till it gets fixed. If I find out anything new I'll be sure to post it. I can't handle sitting at stop signs at 1500 RPM and trying to force it into first anymore! 
Mountain Pass
Joined: Mar 2004
Posts: 249
Likes: 0
From: Santee, CA
Well, no luck for me on the high idle issue. My mechanics weren't able to find anything new or that I had missed. I guess I'll have to suck it up and take it to Ford, where they'll deny that there's a flash for the ECM, then flash it but tell me it was something completely different and bill me $500. Either that or it'll take them 3 trips to correctly diagnose it. Oh well. If I don't do it I'm gonna end up replacing the trannie prematurely. 
Either that or it'll take them 3 trips to correctly diagnose it. Oh well. If I don't do it I'm gonna end up replacing the trannie prematurely.
Thread
Thread Starter
Forum
Replies
Last Post
LARIAT 85
Fuel Injection, Carburetion & Fuel System
1
May 7, 2017 04:17 PM
jimbbski
Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W)
4
Aug 9, 2016 10:39 PM
