Please Help Me Ranger Experts

[fixing_franklin]

Hey guys, so I've got this 1998 Ranger with the 2.5I and 5 speed manual. I've got a problem, my A/C works just fine, but when I turn it on, my idle revs up or sticks. I know the voltage reg. is out or if the ground is just bad on the alternator, so I'm hoping on solving that this weekend. I've had some weird ass battery issues too, like when I shift into neutral it'll read lower than usual. It doesn't move anymore, it likes to stay in the 1/4 way position, I've got a new TPS and IAC but I'm gonna try on the alternator before I do any of that, just want someone who's had this issue before and if there's a fix for it.

P.S. - Brand new battery, brand new terminals and ground, and yes I've tried cleaning the IAC

 

[BlackBII]

Your idle speeds up when you turn on the A/C so that the engine can handle the additional load from the compressor without stalling.

This is normal and most cars do this.

What is the idle speed when the A/C is on?

 

[fixing_franklin]

sadly i dont have an rpm gauge but the automatic ranger i drive at work does lol. but its pretty high, im talking like 3500

 

[fixing_franklin]

while im in neutral it stays the same

 

[RonD]

IAC Valve needs to be cleaned

Idle should bump up with AC on but only about 100 RPM

1998 2.5l 4cyl with manual trans should idle, after warm up, at about 750-800, with AC on, 850-900

After engine is warmed up, and idling, unplug the IAC Valves 2 wire connector, Valve will close and RPMs should drop to 500(barely running) or engine may even stall, either is GOOD, it means no vacuum leaks
If RPMs do not drop then you have air leaks which is also part of your problem

A gasoline engine is controlled by AIR flow, the throttle plate(gas pedal) lets in more air to get higher RPM, the IAC Valve lets in more air to get higher RPM
If a hose or gasket is leaking, then more air comes in so higher RPM

 

[fixing_franklin]

do you think the EGR could have something to do with it

 

[fixing_franklin]

also this new IAC i have has a gasket and seal inside, but when I cleaned my IAC it did not have any kind of seal

 

[RonD]

do you think the EGR could have something to do with it

Probably not, if it was opening/stuck open engine would tend to stall out not idle high


IAC valve was probably taken off before and gasket and seal were not replaced, but don't know

 

[fixing_franklin]

So one can assume that because the IAC doesnt have a seal that could be causing the leak