EGR, EVAP, PCV, ECT, 02's, TPS, IAT
 

Moved pm for more details

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Attachment 499565

Once all the parts are clean, make sure to clean off the Valve Cover opening for the gromment and replace it.
I used a little bit of sealant around the grommet and PCV Valve to help, mainly bevause these should be replaced whenever you do a change. Along with the hoses connecting them to the throttle body housing.
Attachment 499566

4) Engine Coolant Temperature (ECT) sensor

How it works.

Your ECT sensor simply works on resistance and sends that to the PCM then to your gauge. The sensor uses a thermistor which is more accurate at smaller intervals than other types of simple resistance based temperature gauges.

A thermistor is a type of resistor whose resistance varies significantly with temperature, more so than in standard resistors. The word is a portmanteau of thermal and resistor. Thermistors are widely used as inrush current limiters, temperature sensors, self-resetting overcurrent protectors, and self-regulating heating elements.

Thermistors differ from resistance temperature detectors (RTD) in that the material used in a thermistor is generally a ceramic or polymer, while RTDs use pure metals. The temperature response is also different; RTDs are useful over larger temperature ranges, while thermistors typically achieve a higher precision within a limited temperature range, typically −90 °C to 130 °C.
http://en.wikipedia.org/wiki/Thermistor
Where is your ECT located?

On my 2003 5.4L it is located on the front of the engine on the drivers side. See picture below for reference.
Attachment 499567

How can I check it?
First you need to check two things:
1) That your Sensor is working properly, we will use a resistance test for this
2) Check that the plug to the ECT Sensor has voltage.

Checking for a good ECT sensor and plug.
1) To see that the sensor is working proper unplug the connector, it should only have two terminals on it. (This is with the enginge off). Now with the connector off, prob the terminals of the sensor. Place the positive lead on the right hand side and negative lead on the left as show below.
Attachment 499568

Your resistance reading in OHMs should be 60,000 - 40,000 ohms at around 50 degrees Fahrenheit. If it is colder outside your resistance will be higher, so dont worry, that is the way this system works.

Now with everything out of the way let the truck idle until it gets to operating temperate. One it gets to operating temperate re-do step (1) and prob the terminals to check resistance again. Your resistance readings should be between 4,000 and 1,700 ohms from 180-220 degrees F. So it is obvious that resistance increases the colder the engine is, but resistance decreases with an increase in temperature.

It is around 55 degrees here now so I was expecting a resistance reading of around 30,000-40,000 ohms.
Attachment 499569
So I can see that my sensor is working properly.

Below is a general physics depiction of the process a guide that can be use to approximate. (This can depend on elevation and of course your model) This is just a general idea, so as long as the resistance is changing adequately, you should be fine.
Attachment 499570

2) Now all we need to do is prob the connector to make sure that it is getting ~5.0 volts. Simply use your DMM to prob the connector and see what you get. The dark green wire should read +5.0 volts.

Attachment 499571

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Can't wait to see this finished! Thank you!

This should be a sticky lol

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Everything is done up to the 02 sensors. Comments, suggestions, or additions are welcome.

Guys its updated up to index 5... I have a little work to do tonight, so I may or may not be able to finish. I hoep to include (how to's) on fixing these issues and pin numbers on the PCM if time permits. I teach school, so with all this bad weather I have had alot of free time. Feel free to add pictures to the threads, comments, suggestions, corrections, or any of that nature. Thanks

This was a great idea!

Thanks, Hopefully I cant get it stickied.. Just lack a few more

Just got in from doing a little on the side construction work for the gym. Snow day, so I will try to get the remainder of them done today.

Almost done. Just need to link them all together. Let me know what you think, and or add pictures or recommendations.

Wow, nice!

Great Diags and Info. Simplifies quite a bit. With a thread title that should come up in any search.

Great Job ibd; -that took some work. :thumbsup:

Thanks [MENTION=113]Jbrew[/MENTION] I may use some info from your link as well. If you seen anything that needs changing let me know.

No problem. Yea that's a good site, - good stuff! Use it, -I have.

For sure. Help a lot of the simple fixes for most new comers. Thanks

That would mean ensuing you were wrong or something. I wouldn't do that to anyone, - it's not my way... :wink: :laughing:

Haha everything can be opinionated besides mathematics lol.

Really surprised this doesn't have more hits. Thought all these common idle/surging/stalling issues would be interested. I think a lot of people have no idea what the abbreviations mean

I subbed abd have been reading it periodically I just haven't posted but I will say thank you good info

Thank Krack.. I just think some of the newbies don't know the abbreviations or about the information systems within these trucks.

Ya probably not it's just random letters to them lol I've been on here for a while and just now started reading up on more stuff this is really informative I'm trying to learn as much as I can about my truck I actually helped my buddy fix his car recently because of reading about the iac it helps to know this stuff

X2 great info especially the pics!

Give it time, it'll get hits.... Constant.

If this thread would have been here when I joined I don't think a would ever had to ask a question lol

haha i might change the title to : Very simply engine fixes: rough idle etc

Trying to make it to 4000 post and then I'm resigning. Jk

You can't resign, your finally learning something. You have to pay that back buddy. :wink: :laughing:

Haha my learning is complete.

Mines not. Still a smart ass. Oh well, nobody's perfect I hope.

Haha I'm tired if responding to illeterates and non searchers.

Hey , you good at it. Your spelling could use some work, -unless it comes with a dictionary. :wink:

Takles slipping lol.

Haha that's why I teach mathematics for a living. We get English teachers to correct our grammar in publications :) silly english teachers

Hey you able or going to do a write up for the iac I searched and can't find any removal cleaning and testing btw Awesome info

I can

My truck lately has been idling like a pig and it even stalled in an inter section today and I have cleaned the maf checked the pcv and all vacuum lines I could see so would like to tackle the iac but never done it before I like doing a little research before hand especially as it's my only vehicle

Its two bolts and a plug on the back of the throttle body next to the firewall. Its a fairly easy job and you dont even have to take off the throttle body. 30 minutes would be enough time to do it.

And as for cleaning it just never seen one apart before

Well here is the thing. It is only a 10 dollar part. Do you really want to try and clean it or just put a new one in? If you want to clean it some throttle body spray cleaner (less harsh than carb and choke) and play with it until it isnt stuck anymore. If it is really gummed up a throttle body cleaning may be in order.

Oh I do plan on a new one just wanted to see if all a cleaning is what it needed

I got you. Its kind of a pain in the ass but if you take off the plastic throttle body cover it will be a little easier.

When I bought the truck never had one lol but ended up with a buddy that randomly had one so score haha but yea just sucks wen ur in the middle I an intersection and stall... So trying to find this damn bug

I know the feeling. lol good luck and let me know how it goes.

Will do and thanks!

Im working on the write up

Thanks ibd2328!

Its fairly simple. Its an electrical valve. So just do the following.

1) Check for voltage at the connector. This is the two wires leading to the IAC valve.
The the ignition on(not running) . You should see 10-12.5 Volts

2) Check resistance of the terminals on Valve terminals itself.
You should get a reading of 5.0 - 14.0 ohms.

3) Make sure you don't have an interal short.
Check reistance from either one of the male terminals on the valve and then use the other prong to ground it to the side of the IAC Valve itself. You should see 10K or great ohms.

If those all check out, its possible the O-ring/gasket is bad and may need to be replaced. Its a simple procedure, just two bolts. They hard to get to, but it can be done with a 1/4 ratchet and an 8mm socket.

Ima give that a shot this afternoon when I get home thank you for taking the time to write this up!

Thank you to the original poster. I am having some of these issues in my truck and this ought to be very helpful in the hunt for the "rough idling" culprit.

Can someone tell me if the pictures of the ECT sensor are correct in this??? I have that same sensor on my 2000 5.4 but everyone keeps telling me and everything I look up says I don't have a coolant temp sensor. And I have a cylinder temp sensor instead. So What exactly is that sensor on the front right side of the block? if it is a coolant temp sensor anyone have a part#
If you read my post about my issue you will understand my questions here now. https://www.f150forum.com/f6/2000-5-...issues-257614/

Yes, the picture is of the cam sensor, not the ect. I mislabeled them when loading them.

Thanks for the reply. I was just confused and hoping there wasnt a nother sensor i needed to check out

Hi I have a 1997 Ford f150, 4.2 on the passenger side valve cover there is a hard line that plugs into the valve cover, where does the other end connect to???
Thanks

Wouldn't you know it, I am having problems/codes with my o2 sensor, I'm a million miles from home and that's not covered as yet. Wonderful.:blink:

Do you have a DMM with ya??

Hey IBD. Yes, I have a dmm. After reading the procedures you have already written, I'm looking forward to hear your advice.

Is there a particular thread that you can direct me to explaining how to test the o2 sensor/circuitry?

A little update here, I ordered the o2 sensors from Rock Auto and saved good $ right there. In preparation to changing these sensors I sprayed wd40 on the threads to hasten the removal of the old sensors and what do you think occurred? The error code went away as the spray acted to facilitate a good ground and although the code is gone, I will at my earliest time change the sensor anyway. But it is something others may want to keep in mind.

First off. Great work on these details on the first page.

I have a 2003 5.4, throwing the EVAP large leak and small leak codes. Talking to local mechanics, they lean towards changing the charcoal canister. Some sites say the only issue is the valve needing replaced. From my findings there can be a $50-$300 price range on repairing these codes/issues.

I have located an related article however the owner removed the whole bed to replace the canister which is under the mid bed cross member.

What has been the most common issues/repair method regarding the EVAP system leak codes.

Hi, I have a 97 F150 4.6L 137K setting P0401 EGR flow insufficient, and P1151 Lack of HO2S21 Switches-sensor indicates lean. I had a hard misfire on #6, so the O2S is probably clogged. I have replaced the EGR valve (which wasn't caked with carbon) to no avail, and the EGR tube did not seem clogged. The code-setting is intermittent. I have checked the EVR this morning, and it is good per your test. I tested the DPFE and have about 5VDC with the engine warm 180 deg F. I decided to check output with the sensor connected and got intermittent voltage on the ECM output/GRD of 0 to 0.9 VDC. Is this indicative of a bad sensor and the source of my problems?

Also, Advance Auto lists a EGR Valve Sensor for my truck that I don't find in your write-up: http://shop.advanceautoparts.com/p/b...631/20470049-P

O2 sensor?
 

I've been trying for the last month to chase down an intermittent miss in my '03 5.4. Truck runs fine until it gets warm, could be fifteen miles, could be fifty - then starts to balk and miss sometimes a lot sometimes not. Curiously, the miss will also sometimes just go away on its own after a few miles of acting up. Other trips it will continue to get worse to the end, although it hasn't completely quit running yet.
I've had it into the dealership for analysis, they gave me a laundry list of maintenance items - came to over $1,000 - but couldn't tell me what was causing the problem.
I've cleaned the MAF sensor (twice) renewed most of the grounds around the PCM, checked relays and am currently halfway through changing out 1 COP at a time, so far no change. The baffling thing is the lack of consistency in the symptoms - no special speed, doesn't matter if it's under load or not and can happen sooner or later. Last time it happened it threw a code so I went to Auto Zone and got it read - says possible coil or injector and the code was for the O2 sensor. Anyone have a similar experience?
Thanks for all the info on this forum -

Yup, got the same thing. Working on it.

Why don't you start a new thread ? Sounds like a low grade misfire. Those can be tricky , but there are ways to determine and/or narrow it down to the cylinder. From there it's a fairly easy process of illumination. :thumbsup:

Just joined because of this post keep up the good work I was looking around for problems I'm having with my 97 4x4 and came across this so I'm here to stay now hopefully I will find out what's going on with my truck it has a miss, back fires sounds like through the intake and exhaust miss is at low idle and at higher rpms. New plugs and coils egr cleaned and all

Could someone please explain this a little more. I don't understand how testing the harness side can determine that the DPFE sensor is bad. Wouldn't you have to actually test the sensor itself or do you leave the harness plugged in and probe the terminal VREF?

Also it goes on to say;

but in the previous paragraph is says, "With the ignition key on (engine not running), ".

Thanks.

Any suggestions on iat sensor before i take it to get pcm reflashed not getting the 5 volys to plug I jumped the ray red wire to neg termanil on battery it reads 12+ volts but when I turn key on and jum the gray to postive terminal I only get around.012 volts

my 02 f150 w/5.4 motor was in accident and the passenger front was smashed in good . ever since then if motor is cold and u drive it its fine after about 10 miles its starts to stumble and get real rough and lot of vibration when I come to a stop rough idle. so could it just be coincidence and just maybe a fuel filter problem. or ?

Any codes

you should make one on changing the CHT without taking the intake off :thumbsup:

EVAP System
 

I have a 97 f-150 4.2 liter that runs perfect when the fuel tank is toped off but when it drops down to about a 1/4 tank it will no longer idle when you first start it. What I have to do at this point to keep the engine running is manually advance the accelerator by pressing on the peddle. I can then operate the truck by keeping one foot on the accelerator while breaking with the other. Once the truck warms up it will then idle on its own but in a surging manner that oscillates between 700 and 400 RPMs it will continue this rhythmic fashion until it eventually dies.
Once you get to the gas station and fill it up, It will start right up and will idle perfectly.
Any Ideas as to what could be causing this? One other problem it is having relating to filling it up is that once the gas nozzle cuts off; the truck can still hold another 5 gallons. I don't know if that has anything to do with the 1st problem or not.
Any help would be greatly appreciated. There are no engine codes....

Sounds like a venting issue. The charcoal canister is most likely plugged up.

pcv-heated vs nonheated
 

Attachment 486220
Attachment 486221

Attachment 486222
Attachment 486223

3) PCV (Positive Crankcase Ventilation system)




good info on the subject, but my question is about heated pcv. my truck has a heated pcv but the cost difference is astounding. $85 vs $4 for a non-heated pcv. can I use the non-heated pcv in place of a heated pcv without any loss of performance or possible damage to the engine. 5.4L

That's very much untrue. Once you do at least a little minimal research yourself, come back and apply it. I mean , if you can't so much as get the info you posted correct, just how are going understand anyone attempting to help you. I'll help, do all the time, but come on... Perhaps taking it in for service is your only option. Guess we will see.

just what part is untrue about what I posted?

GREAT info!
Maybe you can help. I have a 1999 F150 V6. My temperature sensor, the one in the head, was replaced. Even with the new sensor my temperature gauge over time (20 minutes on the highway) will creep into the red, but the engine is NOT actually hot. It runs normal. The scanner reads 230 which I believe means an open circuit.

To compound this.....my Intake Temperature Sensor was giving off a -40 (open circuit) but would go away after a few miles. The sensor was replaced but I still have the problem with P113 code.

And...my gas guage is now acting strange.

I wondering if these point to a problem with the PCM?

my heated pcv was about 15 or so from Amazon for Motorcraft. On that note a pcv in these trucks needs to be Motorcraft.

I'm thinking that or the harness itself. Pull your battery cables then unbolt the harness from the pcm on the passenger firewall under the hood. Check the pins for water intrusion or corrosion.

Question: Dont have the cash to fix the truck so I plugged up the vacuum hoses for the EGR and the IEVAP sensor,seems to be running and idling just fine the scanner says 695 RPM which is alot better than it was.I have no error codes not even pending ones.
My question: Is the EGR valve closed or open with no vacuum?

I thank you all in advance!

Couldn't Figure out a P0405 code, but then...
 

I recently bought a 2002 4.6 4x4 essentially sight unseen. I brought my code reader and saw it was throwing a P0405 code (EGR circuit low). I knew this was common and easy to fix, so I went through with the purchase. I took it home and peeked under the hood to find a new EGR sensor already in place! This wasn't good, I thought. I checked fuses, and cleaned out the throttle body, but nothing was getting rid of the code! Then a thought stuck me. I looked back at the new sensor, and took double take. The previous owner installed it backwards!!! I popped it off, and put it on the other way. Truck has been running fine ever since!!!

Hahaha that's pretty good.

Damn i just posted asking bout this very topic! But are you positive just see this in haynes manual cuz i have boughyt two and neither shoed 10000 resistance. Perhaps im going wrong swomewhere? Aqny thoughts or advice?

Awesome info and pics. Thank u

I saw only two statements.
1) my truck has a heated pcv
2) but the cost difference is astounding. $85 vs $4 for a non-heated pcv.

So, Brew must be pointing to one of these being in error.
He helps a lot, but sometimes, he... Is like this. My Sr badge only means, I have been here a few years. Check your $20 Chilton/Haynes shop manual, or ask O'Reilly's, or something. He probably read a lot in his earlier days, and expects others to also pay our dues. Let us know, please. If you do this and get stymied, some of us who also don't know will try to dig. We are not loafing but have our own projects.

​​​​​EDIT; I'm old school, so these modern tenth gens are new to me. I cannot fathom a heated PCV, but I'll try to dig tomorrow.

Nice

:rolleyes:

EDIT: They look too different to swap in or out.

My '01 has no heated PCV valve,.but your 2003 might..$90 and is a hose octopus of sorts, as well as a $3 unheated valve.

So I fail on both points I saw.
Heated might be and $85 might be.

Googling this also brought up pictures and how-to-locate.
Look for it. The heated type must be obvious.
Look here,.item 2/2.

https://www.oreillyauto.com/detail/c/standard-ignition/engine-sensors---emissions/pcv/pcv-valve/c24c7c440178/standard-ignition-pcv-valve/std0/oft101

​​​​​​

egr p0402
 

03 4.6 v8 code p0402 my vacuum tube on the top of the egr valve is pulling a vacuum when idling i replaced the dpfe sensor and the vacuum solenoid and its still pulling the vacuum could it be the egr. tube that runs to the exhaust can you test the tube for a clog. i have seen on u tube that the dpfe sensor could not be communicating with the pcm

I haven't heard of them clogging, leaking yes. Tube leak or popet valve malfunction is a 402..check Scorpio here, -

https://www.fordscorpio.co.uk/egrmonitor.htm

EDIT: Scroll past PO402 in red print...keep going to the diagram with 402 displayed, then read below that. The diagram shows the popet as well.

thank you i am confused i just dont know what would cause the constant vacuum at idle there should be none when i pull the vacuum tube off the egr at idle the truck will idle perfect you can feel the line pulling vacuum put it back on and the truck runs with ruff idle so the egr has to be opening and closing thank you

A bad EVR most likley. EVR regulates vacuum via PCM command. Apparently it's not doing so and causing the popet to remain in the open position. That why the PO402 came up... popet valve. The motor is gagging on it's own exhaust gases.

Plug the green line up with something for now (golf tee works), leave it disconnected until you replace the EVR solenoid, These trucks do not need the EGR system to run perfectly fine.

Just reference the diagram in the link I posted earlier to follow what I attempting to explain to you. Again, bad EVR not the EGR valve.

Edit: Damn...guess I lost another one....crap!

:laughing: