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4.0L OHV & SOHC V6 Tech General discussion of 4.0L OHV and SOHC V6 Ford Ranger engines.

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Old 08-19-2005
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Idle Problems!

Okay, I've got some problems here.

First-off, I'm driving a 2002 FX4 w/Manual Trans. Now to the unknown problem.

Sometimes when driving, and say the light turns red ahead, I'll push in the clutch and take it out of gear, but the RPMs stay up near what I was driving at (last was at 2500-3000), until I slow down. I dont know, but assume that all Rangers do this for some reason?

Second problem is this: I was just driving to the grocery store, about to turn it, when all of a sudden I notice I have no power steering! I look down, and my Chekc Engine Light is on! Now, obviously the engine stalled, but I can only assume it went down to Idle too far. I know I didnt stall it by leaving it in gear because otherwise I would have come to a rough stop. The Radio was still on and going, so I had no idea. I have noticed this also before, but never has it stalled. The truck idles a little bit above 500RPM, and sometimes when coming to a stop, after it comes down from 3000ish RPM (as mentioned above), it will dip down below, but then bounce up. Was this just a fluke that it stalled, or what?

Right as I parked the truck at the store I opened up my glove compartment and looked at my warranty info. Figures, I'm just over by 200Miles. And I know someone is going to say something about checking my Vacuum lines, but how and where are the only questions I have.

Anyone?
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Old 08-19-2005
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Clean out your Mass air flow sensor, located on the intake tube.

That should do it. If not..

IAC sensor is jacked, or dirty..
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Old 08-19-2005
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Quote:
Originally Posted by FoMoCoEdge
Clean out your Mass air flow sensor, located on the intake tube.

That should do it. If not..

IAC sensor is jacked, or dirty..
Brake Cleaner? Or no?
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Old 08-19-2005
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That should do it.
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Old 08-19-2005
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that improves your Idle? using brake cleaner?
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Old 08-19-2005
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For your MAFS sensor, use electrical contact cleaner that leaves NO film/residue behind. For IAC, you can use brake cleaner I believe but 99% of the time, when the IAC goes south, cleaning it gives very short term relief if any.

If your MAFS is dirty, cleaning it will help your idle a lot. Seems his IAC is taking a dump IMO. Mine is starting to act like his truck...when coming up to a stop sign or red light or making a turn w/ my foot off the gas, RPMS will dip to 300rpms on the tach gauge and the engine will almost stall out then they will jump up to about 700.
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Old 08-19-2005
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i agree IAC, i had the same issue, its like 40 some buck new from the dealer too
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Old 08-19-2005
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(Sorry to hijack the thread...) For you guys that changed out the IAC, how many miles did the truck have when you changed it out?
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Old 08-20-2005
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Ahhh....My truck has done that (IAC poblems) for the past 6-7 months. Went through 2 IACs...I never thought the MAF cleaning would help, i'm doing that tomarrow.
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Old 08-20-2005
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what would be the name of the cleaner I need for the MAS
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Old 08-20-2005
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Quote:
Originally Posted by Morph
Sometimes when driving, and say the light turns red ahead, I'll push in the clutch and take it out of gear, but the RPMs stay up near what I was driving at (last was at 2500-3000), until I slow down.
If the idle is hanging at 2500~3000, as stated, you can forget about the MAF as a cause. The MAF has a major influence on the air/fuel ratio. At idle and part throttle, the engine runs at stoichiometric (chemically balanced A/F) mixture and stoichiometry produces the highest possible engine speed. Any deviation from stoich, richer or leaner, will slow the engine speed, not raise it. Yes, a dirty or defective MAF can cause stalling but it cannot cause the RPM to hang.

By far, the most common cause for the high or low RPM problem is a sticky/dirty IAC valve, even more so if you run an oiled gauze filter like a K&N.

The Throttle Position Sensor can occasionally give a high idle problem on deceleration but it is rare. It happens because the PCM cannot sense the closed throttle position so it keeps the IAC open too far and too long.
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Old 08-21-2005
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Thanks for all the replies, I think I'kk be visiting the Dealer tommorow, see what happends.

Also, For RangerEdge02, I currently have ~40,000 mi on it.
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Old 08-22-2005
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Is the IAC on the right side of the throttle body and held on with 4 bolts is this the right thing?
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