idle not increasing when a/c is turned on.. new iac and nothing

[Hardwareman]

NO, no problems shifting or anything. Mine's a manual transmission too, is yours? I've actually got some major problems going on right now and can't quite figure it out.

When my Ranger first starts up in the morning or just from sitting for a while it idles horrible and sounds like a "pop pop pop pop" coming from the exhaust when in gear and decellerating. After it warms up it's not near as bad but still a bit noticeable. I just changed out my DPFE sensor and that did'nt fix it so I think I'm going to check/replace my EGR valve.

If my EGR valve is stuck open it would allow a lot of excess gas into the intake and cause what I'm experiencing I think, which is why I'm thinking the problem's not as bad at idle you know? Cause things are warmed up and the engine can tolerate a little more air through the intake.




Allen

 

[BobbyB2300]

Cuban dude:Have you cleaned your Mass Airflow Sensor(MAF)? Are you getting any codes?

Hardwareman: EGR problems are the root of all evil in these little four bangers. Remember, there are three components to the EGR system; DPFE, EGR solenoid, EGR valve. Any break in the chain will cause these problems. DPFE is just the most common.

 

[cubanfisher]

well mine is automatic and this idleling problem is getting very annoying. dont know wat else to do, btw do you get the 10 volts at the iac?

 

[Hardwareman]

Cuban dude:Have you cleaned your Mass Airflow Sensor(MAF)? Are you getting any codes?

Hardwareman: EGR problems are the root of all evil in these little four bangers. Remember, there are three components to the EGR system; DPFE, EGR solenoid, EGR valve. Any break in the chain will cause these problems. DPFE is just the most common.

Thanks Bobby,

I have'nt changed out the EGR valve or EGR solenoid yet, only the DPFE sensor. I have an extra EGR solenoid so I'll probably change that out today and see if there's any change. I don't have a vaccum pump otherwise I'd of checked the EGR valve already. Maybe I'll go to AutoZone today and rent one. I've been very busy at work this past week and have'nt had the time to dig into it. I really appreciate all your help.

Cuban, I don't remember if I have the "at least 10.5 volts" at the IAC connector but I promise I'll check it today and post up the results. Take care.

Edit: I guess while I'm there I'll check the vaccum lines going to the EGR valve/solenoid as well. Do you guys know wether or not the vaccum causes the EGR valve to close or open?


Allen

 

[Hardwareman]

Ok Cuban I went out and checked the IAC connector and sure enough I'm getting the full voltage from the battery to the sensor. I've already changed out the sensor and nothing changed so I'm starting to think that I have a bad PCM.

I'm starting to run out of things to check and replace you know? Plus, I just talked to a guy last night on the phone who told me he had a misfiring problem that he could'nt figure out so he changed out his PCM and his Ranger started to run puuuuurfect again. Makes me wonder. I still need to investigate the EGR solenoid and valve though.

At this point I'm probably going to end up replacing the PCM at some point because I just need this problem gone.




Allen

 

[cubanfisher]

ok now that egr comes into the topic this is a newbie question. i have a 94 ranger.

im not sure if i have one, atleast it looks like i have one on top of my fuel rail and has a vaccuum line that goes in the vacuum distribution tower. all i know is that i take off the line and plug the end and i hear no difference.
is that the egr?

im pretty sure i down have a valve or anything. yet again i have no idea but i have a feeling that being a 94 and not a 95+ makes a difference on the egr.

 

[Hardwareman]

Yeah, you have an EGR valve all right. They started coming out in the early 80's I think. It should be connected to your intake manifold somewhere. It's got a vaccum hose going into it. What you're talking about is more then likely the "FPR" that's on the fuel rail. I don't think you have a problem with that.

I still can't see how that (egr) would affect the IAC not working however.



Allen

 

[jobar]

Hey guys, sorry im so late but im having the same problem. The only difference in mine is, when my rpm's drop they pick back up when ideling. But, when I drive down the road it kills the engine. Any ideas.

 

[Hardwareman]

OK, well just got done swapping out the rear coil pack. I swapped the front one out about a week ago. So that rules out the coil packs. Swapped the fuel injectors, plugs, wires, both crank and cam sensors, cleaned throttle body, MAF sensor, intake, new PVC valve and hose, you name it I've done it.

I also changed out the intake air temperature sensor becasue I had an extra one of those laying around too. I'm just grabbing at straws now but I'm pretty sure if it's not the EGR valve then it's definitely the PCM.

They do go bad you know.





Allen

 

[Bryan22]

Ya i'm kinda in the same prediciment as u hardware man! I've changed a buncha stuff to no avail, how much is a new PCM and where would you find one? you think one out of a junk yard would be a good idea, or would that be waste?

 

[Hardwareman]

Ya i'm kinda in the same prediciment as u hardware man! I've changed a buncha stuff to no avail, how much is a new PCM and where would you find one? you think one out of a junk yard would be a good idea, or would that be waste?

Well it depends really on what's going on with your Ranger bro. What is it doing? See, I've changed out and/or checked every sensor and wiring in each of the circuits and all is good. There's really nothing else that I can change out except the EGR (which it very well may be) or the PCM.

I have to check the EGR though because the symptoms I have are basically only at idle and the EGR "definitely" can/will cause that. After that, I'm willing to bet money that it's the PCM. As far as acquiring another PCM, you actually have to go to either e-bay (or another place online), or like you said.......a salvage yard. If you do go to a salvage yard, try to get a PCM out of a known wrecked or crashed vehicle this way you know the vehicle was running when it arrived at the wrecking yard.





Allen

 

[cubanfisher]

hey well i still dont think i have an egr. im almost certain i dont have one ill take a picture of my engine bay today and if anyone can locate it for me. or if anyone have a picture of one in a ranger.

 

[cubanfisher]

heres a picture of a diagram with the egr valve i think can someone pinpoint it on this pic on A5 theres a egr type sensor which i do not have on my truck

 

[cubanfisher]

any idea?

 

[BobbyB2300]

It's right above the EGR solenoid C174. It's round and has a vacuum tube in the center that is connected to the EGR solenoid. It's on top, close to the firewall. Maybe somebody pulled it off to defeat the emmisions. Or, maybe this is a beast I've never seen before. This diagram shows the entire EGR system except the EGR valve itself.

(edit: I just noticed you say you have no DPFE at A5, that is an EGR system component. I'm thinking this truck doesn't have California emmisions. Maybe that's why there's no EGR valve).