help with rpm's and idle issue

[thor1701]

ok i've read this place enough to know that normal rpm's at idle are around 500 to 700....now that being the case, when mine get that low, my ex sounds like she's about to die, the lights flicker and the voltage meeter bounces around....cleaned the maf and cleaned the iac, plan on replaceing the fpr and the o2 sensor as soon as they come in, replaced sparks and wires and changed oil, also recently replaced the tranny vac modulator, no codes or leaks that i can tell, tho she smells real bad....

secondly, when driving the highway on level ground, i used to have around someware between 2000 and 2500 rpm's when going 65 mph now im at like 3000 rpms sometimes alittle over

91 explorer EB version 4.0l v6 auto tranny
any sugestions would be most helpfull

 

[mudbug0426]

how many miles do you have? and how often does it want to die when at idle?

 

[thor1701]

a few billion miles i know that, i know the thing had to completly roll over at least once
and all the time when the rpm's go down to 500 600, when i start it up....when i stop at lights, tho once in a while the rpm's down drop when i stop they hover around 1000

 

[mudbug0426]

is the check engine light on? even if not, if you have a scan tool, see if the computer is putting out or has and pending codes. if you dont have one, take it to autozone or a similar parts store and have them read it.

its hard to say without knowing if the computer is seeing a problem or not

 

[thor1701]

yep bought me a code reader and at first it was a code 41, lean system, then i did a tuneup cleaned the sensors rebooted the computer and everything passess

 

[thor1701]

well now the idle doesnt go down to 500-700 anymore, it just hovers at around 1300 and 1500 rpm's
all i did was clean the maf and the iac
i just want it back down to normal 500 700 idle without it acting like its going to die wish she would make up her mind
<sighs>

 

[mudbug0426]

when did you last replace your iac?

 

[thor1701]

i've never replaced it, as far as i know its the original
i just sprayed some cleaner in it to clean it all out
did the maf at the same time

 

[mudbug0426]

i would try replacing the iac if its never been replaced, that could very well be your problem or at least a big part of it

 

[thor1701]

i'll look into replaceing it after im done with the rest of the stuff, the fpr and the o2 sensor, then have to figure out the rpm's when going 65 on the highway, they cant make up their mind what they gonna be lol

 

[mudbug0426]

a few billion miles i know that, i know the thing had to completly roll over at least once
and all the time when the rpm's go down to 500 600, when i start it up....when i stop at lights, tho once in a while the rpm's down drop when i stop they hover around 1000

ok, when you said it completely rolled over at least once, meaning its passed 999,999 miles and rolled back over starting at one?

 

[thor1701]

yes i belive it has
like i said its a 91, and i just bought it like 4 years ago...
and i think it rolled over on me when i was driving it but i honestly cant remember

 

[mudbug0426]

ok, well give me an update on any changes after you put the new parts on. i would still replace the iac valve myself.

do you have any history of work that had been done by the previous owner? any motor work that you know of?

i would also try changing the fuel filter if you havent already

 

[thor1701]

well hopefuly it will be sometime next week, waiting for a fpr to come in that i got online, welp i was out driving tonight and the weird idle started up again, it didnt go down to 700 or lower, it went down to 1000 and it started idleing rough and shaking alittle....yeah most likely i will get a new one, just need to be able to afford it

 

[thor1701]

welp
replaced the fpr replaced the iac and replaced the o2 sensor
im not getting any codes for ****, it still smels like gas real bad, almost to the point of makeing me sick when i sit in my truck, it still idles around 1500 or alittle under and i still have bad rpm's when im doing 65 on the damn freeway,
a man can only read so much on this website lol
i just dont know what to do and i feel like im just wasting money on trial and error stuff

 

[boggs1227]

if no codes are showing up then it maybe related to the fuel system.like mudbug said i would replace the fuel filter for starters also what does the fuel pump sound like when you turn on the key to prime the system ? ...good whirrr ?? ...it's cheap and easy to do and can only help out the engine.you said you cleaned the maf ...did you remove it from it's houseing and clean it with the proper cleaner? did you test out the tps sensor ? if bad it could be telling the engine to dump more fuel in at idle ....and will also screw with your idle speed .

any really bad back pressure in the gas tank when you undo the cap ? could be the that the evap soilnoid may be messed up and or the tank pressure valve is not venting properlly .but the solinoid would give you a code tho if it was going bad....

 

[mudbug0426]

check your fuel pressure and do a compression text next. both tools needed you should be able to loan from a local parts store near by

 

[thor1701]

if no codes are showing up then it maybe related to the fuel system.like mudbug said i would replace the fuel filter for starters also what does the fuel pump sound like when you turn on the key to prime the system ? ...good whirrr ?? ...it's cheap and easy to do and can only help out the engine.you said you cleaned the maf ...did you remove it from it's houseing and clean it with the proper cleaner?

any really bad back pressure in the gas tank when you undo the cap ? could be the that the evap soilnoid may be messed up and or the tank pressure valve is not venting properlly .but the solinoid would give you a code tho if it was going bad....

lets see, the fuel filter is fairly recent, the pump sounds ok makes like an electronic noise like something's moving, tho if i had my way i'd replace it beacuse when im almost out of gas, and im like comeing off the freeway, she turns off on me, then i have to sit for 30 or so seconds for it to start up again, then drive to the nearest gas statoin and fill up, but i cant beacuse i havnt a clue how to drop the tank and i cant afford to have a pro do it, yeah i cleaned the maf, took it completly out and sprayed the hell out of it, and no i dont have any issues with takeing the gas cap off
also i dont know how to test the tps
in the mornings when its cold i have to pump the gas alittle to get her to start also

 

[thor1701]

check your fuel pressure and do a compression text next. both tools needed you should be able to loan from a local parts store near by

like auto zone? and im not sure how to do a compression test

 

[mudbug0426]

yes an autozone works fine, lets start out with a fuel pressure test.

go there and get the tool, tell them you need to test your fuel pressure.

and remember your talking on a forum lol, there are tons of write ups and people who can help walk you through things like dropping your tank to change your pump.

lets try one thing at a time.

if your fuel pump is bad or is dying, your motor wont be getting the amount of fuel it needs which would make it do alot of crazy stuff.

keep in mind you have alot of miles on your motor, these symptoms your having could be caused my multiple issues or parts that are in poor condition