Hello everyone new here. I have a 95 f150 that is having idling issues and is sucking gas. It is idling low and ruff at idle and if you are driving it is idling high. While I am driving if I let off gas and put in neutral idle stays up. I have had eng light come on several times but will not stay on so it can be scanned and showing no history. I have gone thru and changed wires, plugs, cap and rotor along with timing chain and water pump. Needed it but still has not made it any better. Any thought?

The reasons I did the tuneup stuff. It has been 50,000 mls sense I had changed plugs, wires and stuff. 120,000 mls on the timing chain. and 231,000 mls on the original water pump so yea I would say it need to be done.

I have track it down to looks like the EGR sensor. If I unplug it the idle and vacuum comes back to the 20 in. hg. that the book say'es it suppose to have. When it is plugged in it has about 12 in hg and idle like crap. When I unplug either the green line in the EGR or the sensor vac comes back to what it should and idles smooth out. Is this my issue or is it masking something else?

Thanks a ton!!!
Jaime

 

How are you checking for codes? There should be stored codes because of the CEL coming on. Very rare instances, it's a bad PCM. But let's not go there yet.

 

When you say EGR sensor, are you referring to the electrical connector that plugs in to the EGR position sensor, or are you referring to the vacuum line that plugs in to the EGR valve? Better yet, while the truck is running and at idle, pull the vacuum line to the EGR valve, if it has vacuum, you can check with a gauge, then its probably something causing the valve to open when it should close, either a solenoid, incorrect line routing, short, or ecu commanding open when it shouldn't. let us know how youre reading the codes.btw, we love pics!

 

There are no codes coming up. I have taken it to my cousin who is asa with a machine and nothing comes up. Any thoughts?? Yes the EGR position sensor plugged in runs like crap unplugged runs smooth. or leave it plugged in and pull the vac( green vac line on EGR ) runs smooth.

 

How is he running it? These fords are unique in that there's two code reading modes, one is with the vehicle not running and the other while it is running. Sometimes diagnostic situations arise where it will only show the codes in one mode, not the other. I would be sure he's checking in both modes. Also, with the key on, engine not running, does the check engine light come on? Would almost seem like the ECU, because at idle, the computer should be sending no voltage to the egr solenoid, to keep the valve closed, so even if the position sensor were showing open, it would only want to command it to close, but for some reason, when a sensor in that system goes offline, it commands the close. If a malfunction in the sensor or solenoid existed, it should cause the ECU to show some kind of code or malfunction.

 

I think he does it both ways. He hooks it up not running after a few he say'es start it up. So guessing both. Yes on the eng light being on when you click on ignition. It has always done that thou. but I think it use to go out after a few not sure. That's what sucks about all these dang sensors. Cars and trucks ran just fine with out them. Could a MAP or the TPS possibly be causing this as well?

 

At the very least you should be getting the 111 / 111 "all clear" code. If not, there is your problem which prevents anyone from diagnosing the issues at hand. Many times the diagnostic connector pins are corroded which makes pulling codes difficult. Use some contact cleaner or better yet use a small screwdriver or nail file to shine up the contacts. Until you can pull those codes you are shooting in the dark.

Start with the Key On/Engine Off (KOEO) test and Continuous Memory (CM) display. Once you have any issues taken care in those tests, then move onto the Key On/Engine Running (KOER) tests.

 

Cool thanks. I'll give that a try this week. Get some contact cleaner and get my Oring picks to scrape them off to see what happens. Then go from there.

 

Why not Ohm the EVP?

But I agree, without getting your codes, you are shooting in the dark.

 

Ok everyone got some codes off it. The lil info I can find is the IAC and the TPS. Thanks!!

KOEO
121, 565, 121, 565, 112, 212, 124, 212

KOER
412, 121, 411, 632, 412, 121, 411, 632

 

121 is most likely a TPS problem. Use a meter to verify the output signal.

565 is a problem with the vapor canister purge valve (CANP). Check the connections.

112 can be caused by not warming up the engine before running the KOEO/KOER tests.

212 (Loss of IDM input to EEC or SPOUT circuit grounded.) is usually caused by having the wrong Ignition Control Module (ICM) installed in the truck. Your 1995 uses the CCD-style (black colored ICM) ignition system. If someone has installed a Push-Start (gray colored ICm) it will trigger this code. Some have reported driveability issues because of this as well.

632 is operator induced, you never cycled the O/D switch during the KOER tests.

124/411/412 are interesting. This is not necessarily an IAC issue. If there are any vacuum leaks, with a resulting high idle RPM, then you can have these codes pop up. Check for vacuum leaks before going too far. I might also suggest cleaning the IAC before blindly changing it out.

 

I went thru the TPS the other day was a bit off from what the book said it should read.

CANP? What and where is that?

The vehicle was warmed up. ? My temp sensor has been broke for a bit now think that may be why that one came up?

I will look for the ICM to see if that is the wrong one.

Yeap missed the O/D test.

I went thru the vac lines the other day checking to see if any may be loose. Found nothing. I also sprayed carb cleaner around all vac lines and around the intake to see if the idle would change got nothing. I pulled the IAC and the EGR cleaned both of them as good as I could.

Thanks for the help

 

On a 5.0/5.8L engine the Canister Purge (CANP) solenoid is located near the throttle body:


This solenoid allows the fuel vapors from the charcoal canister/fuel tank into the intake when the PCM commands it to open.

There are two different engine coolant temperature sensors. One is the Engine Coolant Temperature (ECT) sensor that sends feedback to the PCM. The other is the temperature sensor for the dash gauge.

Here is a photo showing the location of them on a 5.0/5.8L engine:

courtesy of subford

You are interested in the ECT sensor.

What is the idle RPM in drive and neutral with the engine warmed up?

I am not a fan of the spray method to find vacuum leaks. These fuel injected engines have vacuum reservoirs all over the place. Any and all of them can cause a vacuum leak and still pass the spray test. Did you check the coffee can looking reservoir on the passenger side fender? It frequently rusts out on the bottom. There is another small plastic reservoir on the blower case that can crack and cause a vacuum leak. The HVAC system is all vacuum controlled, a few cases of a broken vacuum motor or hose under the dash have caused a vacuum leak.

I also question your earlier statement about pulling the vacuum line off the EGR valve. There should be no vacuum applied to it under idle conditions. Typically if there is vacuum present and the EGR valve opens slightly you will get an EGR position related code.

Start repairing the items that are triggering the first few codes, once they are fixed clear the codes, drive the truck and check again.

 

Cool I was wondering what the round can looking thing was. Will an ohm test work for it?

Looks like the ECT is the one that I had changed. So need to look at the other one.

Engine idle when warm. Well it is 2 different ways. Sometimes it about 1100rpm and sometime it around 500 rpms.

That is not all the time on the EGR vac. Sometimes there is vac sometimes its not.
It would be diff if it was the same all the time, but its not.

I'll keep checking for vac leaks and check the CANP and TPS more and/or replace and recheck.

 

Got up early this morn switched out the TPS and IAC sensor WOW what a difference it made. Like a new truck. I'll drive it for a bit then then run codes again to see what I get. Thanks for all the help!!