First post on this website. So first, Hi all.

Second, I have a 2000 ranger xlt trailhead 3L with an odd sort of idle problem. In certain situations, the idle is just simply to low. the engine won't die, but it will sit around 500 and kinda sputter. If i just tap the gas, the idle will go back up to where it should be.

It is intermittent. It happens usually when I have to brake hard or in bumper to bumper traffic. It will also happen just braking normally, but with much less frequency. I can prevent it by popping the truck into neutral just before I have to brake. Usually, when it happens once, it will continue to happen for a few minutes. Sometimes it can go a week without doing it once. Sometimes, it does it for 20 minutes at a time. Like I said, its very intermittent, and only seems to happen while either braking/deccelerating.

Things I have tried (or done recently due to maintanence):

replaces abs/speed sensor
Brake booster test (per haynes)
Plugs, wires, air and fuel filters
oil change
checked and cleaned iac and pcv
checked all vaccum lines

The documentation online appears to point to an iac or some other electronic vaccum dealie next to it. I would rather not just start throwing parts at it and was hoping someone here might know of somethign I have overlooked.

Anyhelp would be appreciated.

 

First, welcome to FTE!

Based on what you describe and what you've recently done, I would suspect the IAC valve is bad. Keep in mind that, if an IAC is bad on a more recent vintage Ford engine, cleaning it won't do much of anything. Only some of the older IACs could be cleaned.

Another possibility I can think of would be that maybe the EGR valve is sticking open occasionally (the EGR valve should be closed during closed throttle conditions).

You might also consider cleaning your MAF sensor and throttle body:

Cleaning Your MAF Sensor

Cleaning Your Throttle Body

 

Thnxs for the info. I took my truck to my dad's shop today and got it hooked up to his scanner. He ran it through a bunch of tests (around 30 minutes) and it had absolutly not one single code. It did have a slightly higher than normal TPS number (.8 insteasd of, i think he said .5 is normal, don't remember though). IAC numbers came back inside acceptable range, as did egr.

Did some quick flash thing (not the full reflash). Won't know of that fixed it or not for a few days. Solution for the moment seems to be drive it for a few days. If it does it again, bring it to teh dealership for a reflash. If it still isn't good, then replace the TPS.

I'll update this again when I get a solution.....

 

Hey, if it only does it when the fuel tank is nearly full, check this TSB out. Mine has a full-blown case of it. Dealer says the solution is basically a vent line replacement. Would love to get mine fixed, but I'm a little financially challenged right now so I'm just dealing with it. It really is only an annoyance and only when the tank is 3/4 or more full. BTW thanks FTE, looking into this problem is how I found this website in the first place.

Make : FORD
Model : RANGER
Year : 2000
Service Bulletin Num : 0194
Date of Bulletin: MAY 14, 2001
NHTSA Item Number: 620157
Component: ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL
Summary:
SOME VEHICLES MAY EXHIBIT A STALL OR IDLE DIP (BELOW 450 RPM) DURING DECELERATION OR WHILE TURNING THAT WILL ONLY OCCUR WITH A FUEL TANK LEVEL OF 3/4 OR GREATER. GENERALLY THE STALL OCCURS WITH NO MALFUNCTION INDICATOR LAMP (MIL) OR DIAGNOSTIC TROUBLE CODE (DTC) PRESENT. THIS MAY BE CAUSED BY A RESTRICTION AT THE Y CONNECTION IN THE REAR FUEL VAPOR LINE. *TT

 

Nah, mine does it basically whenever it wants to. Full tank, nearly empty, and anywhere in between. It never idles below 500 when it does it, and seems to hold it at 500 like the truck "thinks" that's what it is suppsed to be doing. That is until I tap the gas, and it begins to idle correctly again.

Started doing it again. Going to take it to a dealership sometime this week to get the system flashed.

 

I hear ya, there's nothing worse than an "un-diagnosed" problem...just give me a good old-fashioned flat tire any day...at least I can fix that Good Luck