TPS help on 98 Ranger 2.5

[kjw86ca]

Hi,

Can anyone give me a step by step or a picture on where I can find the Throttle Position Sensor on a 98 Ranger w/ the 2.5L? I think I need to replace it, I am having high idle issues after shifting from gear to neutral (RPMS climb steadily to around 4500K and then drop down.)

Any help would be great! Thanks.

 

[slolearner]

cylinder shaped thingy attached to throtle body on back side ...has a wire going to it from top I believe.....

 

[Bryan22]

the one on the back of the throttle body is the IAC it controls the idle. the TPS is on top of the throttle body. but i would not just start replacing things. you might start by cleaning the IAC and see if that helps.
so when you take your foot off the throttle and take it out of gear it winds up to 4500rpm? if you punch the throttle in neutral does it come right down or does it take a while?

 

[ecogenie]

the one on the back of the throttle body is the IAC it controls the idle. the TPS is on top of the throttle body. but i would not just start replacing things. you might start by cleaning the IAC and see if that helps.
so when you take your foot off the throttle and take it out of gear it winds up to 4500rpm? if you punch the throttle in neutral does it come right down or does it take a while?

Guess the person who posted this never came back. I am having the same problem with same engine. The throttle takes time coming back down after it is punched. I was told that it could be the EGR valve and to put a BB in the vaccum hose and this would fix the problem. What are your toughts on this?

 

[Bryan22]

just read your message.was confused, haha. but, i doubt it's the EGR. usually if theres a problem with the EGR system you'll get a code on the newer vehicles. and it'll more than likely drag the rpms down to almost stalling. No make em hang.

As i told the OP you should start by cleaning the IAC and make sure it's not getting stuck open. it's basically a bypass valve for air going into the intake manifold. and if it's stuck open or not closing completely when it should, it'll cause a high idle. Also could have a small vaccum leak somewhere, someone could have messed with the screw on the throttle body... many things. But i'd start with checking vaccum lines and cleaning the IAC and let us know what you find.

Good luck!

 

[greenpus]

Guess the person who posted this never came back. I am having the same problem with same engine. The throttle takes time coming back down after it is punched. I was told that it could be the EGR valve and to put a BB in the vaccum hose and this would fix the problem. What are your toughts on this?

how much time are we talking about? Is this truck new to you? The 2.5 on this truck pauses and does take some time to drop back to idle. If you're talking about taking more than 3 seconds than you may have an issue.
On the 98-2000 2.5 there are wire connection issues with the TPS and ford sent out a bulletin to replace the TPS connector. First thing I would do is buy an electronics cleaner plus dielectric grease. Spray the connectors on the IAC and the TPS sensors. Reseat the connectors several times to help clean the connectors and spray again. Let the connectors hang and dry for a few minutes. After the connectors are dry, put dielectric grease in the connectors and plug in. If you still have issues with idle then replace the IAC. Many will tell you to clean the IAC but it's pointless. Replace it.

 

[tajvelocity]

just read your message.was confused, haha. but, i doubt it's the EGR. usually if theres a problem with the EGR system you'll get a code on the newer vehicles. and it'll more than likely drag the rpms down to almost stalling. No make em hang.

Hmm, then maybe my problem is with the EGR. Not trying thread jack a jacked thread, but my 99 2.5 has loopy/low idle and stalling issues. I think my Hayne's manual said to check the IAC, you take it out and shake it. If it rattles, the valve is working. Maybe that's BS though.

 

[greenpus]

Hmm, then maybe my problem is with the EGR. Not trying thread jack a jacked thread, but my 99 2.5 has loopy/low idle and stalling issues. I think my Hayne's manual said to check the IAC, you take it out and shake it. If it rattles, the valve is working. Maybe that's BS though.

IAC don't rattle. The PVC does. Two different things.
The IAC is a solenoid that opens and closes. Haynes sucks.

 

[tajvelocity]

Thaaaat’s right. It’s been a while since I’ve checked them. I unplugged the IAC and the idle got worse, meaning I suppose that it was working. The PCV rattled.

 

[Bryan22]

it could be the egr. take the vaccum line off of it and apply vacuum to the valve. if you don't have a pump, you can just suck on the other end of the vacuum line. doesn't take much to open it.

If the truck idles worse or dies, then the egr is probably working. if nothing happens the egr is most likely stuck open.

I'm not sure if the newer(your) vehicle is equip with a DPFE, if it is, it could be going bad. i had a bad dpfe trying to open the egr more than it should've and make the truck die, but my truck threw a code. I'd think your truck being a 99 would throw a code if you had a problem with the egr system.

anyways, just give that simple test a try and let us know.

-edit-

Just read your thread, and you stated you allready checked the EGR. assuming that it isn't giving you any codes, i'd look more into the fuel system. Still you can test the egr for free so give it a try, but i wouldn't bet on it being the culprit. Get a fuel pressure guage (i got one for $10 at harbor freight, and it works just fine) and get some readings at the rail and report back.

Good luck!

 

[ecogenie]

Got the answer from FordRangerForum.com !!! Take a BB as from a BB Gun and take off the vaccum hose put the BB onto the ERG hole then put the hose back on. No more problems when shifting gears and the engine rebbing up as pushing the gas peddle to the floor. Crazy as it sounds it really does work. Just do it!!!

 

[Bryan22]

i wouldn't recommend doing that. probably won't pass smog now. and it's a band aid. Plus i just can't believe that worked. haha. but it's your truck, if your happy then run it.

All the EGR valve does is introduce burnt exhaust gasses into the combustion. If the egr opening is causing it to actually rev up, i'd be looking for an incoming source of fresh air somewhere between the egr valve and exhaust manifold. That or maybe a hole in the EGR diaphragm letting air through the vacuum line(vacuum leak). Still like i said if you're happy to not pursue the real problem, it's your prerogative.