My86F150

I have been chasing down some other issues before I could get back to this line of thought. I ended up removing the dual tank filter reservoir and installing an electric switching valve and inline filters. Something else I picked up off the forum here.
Now I am back to using the code reader. I have a code 54 on my KOEO test. Intake air charge temperature sensor open. I replaced this with something I found in China (seriously) when I was putting new gaskets on the intake manifold. The connector on the old one broke off and NOBODY knew where to find an OEM.
On another forum I found the resistance and voltage values I needed to test the sensor.

The resistance values seemed reasonable for the engine temperature but the voltage value never came off of 4.68 V. I do NOT live in a state with those temperatures! This was with the connector attached to the sensor and the engine running.

Bypassing the sensor led to some really rough idling before it warmed up.

Clearly this sensor is junk and I should expect the same from the next Chinese knockoff. Do you know a work around for this or a source for a reliable replacement?
I cannot go on to KOER testing until this is resolved.

Steve83

Code readers are notoriously UNreliable for EEC-IVs - I highly recommend using a simple jumper wire (paperclip, etc.) as explained in this caption:


(phone app link)

This explains how to test these early Ford temperature sensors:


(phone app link)

Since all early ACTs are electrically identical, and function the same way, anything that can be mounted & sealed to the engine, and connected to the wires, will do the job. I'd look for the '87-93 style because it's the most-common (easiest to find in parts stores & JYs) even if it meant re-threading the intake manifold & splicing a new pigtail connector on. But I suspect it'll screw in, and it might even plug up. If you can't find a MotorCraft, look for an Echlin(NAPA), Standard, or Wells/BWD.

If you don't have a Haynes manual, this would be the time to invest in one, but read this caption before buying one:


(phone app link)

For more, I need to see ALL the truck's details in your signature (so they appear with each post) as described in this caption:


(phone app link)

It would also help to put your location in your profile.

My86F150

I have created a signature and updated my profile. I don't know if it will post until I start a new thread. Sorry if it posts twice this time...

I didn't know about the code reader issue on the EEC-IV systems. I have the procedure in one of my books. I'll try that in the future just so I know the technique. I have a Chilton and a 36058 Haynes. Each has it's own merits. I must admit I still have not read cover to cover of either of them. Maybe some day when I am not trying to keep the scary tow truck away I will get to read them all the way through. LOL

REALLY good tips and links. Thank you.

If I can find one of those decent quality ACT's on Rockauto.com, I will probably just replace it. Then move on.

86 F150 XLT 2WD standard cab, long bed. 2K miles on rebuilt light duty 5.0 EFI. Reverted rear end to stock in 2016. Swapped AOD for 4 sp Borg in 2017. Dual tanks w/ Poldark electric switching valve. Grey or brown (depending on how close you are to the rust patina)

My86F150

Just a follow up on the work with this truck. I think I can finally see the light at the end of the tunnel! I got a new temperature sensor from Rockauto.com for an 87 Ford. It worked perfectly. Unfortunately, along the way of fuel tank switching valve and fuel filters, some dirt got by and clogged an injector. On these EFIs, access to half the manifold is covered up by the plenum. I know I spent more money than necessary but I bought four re-manufactured injectors, pulled the plenum and swapped out one bank of injectors. I figured that in a worst case scenario, I would have to take it apart (again) and put those injectors into the other side. I got lucky and it turned out to be on the side I swapped. Runs smooth as a top now. (except for that little exhaust leak) LOL.

Oh well, it's a good thing I like working with my hands. Thank you everybody for all your tips and help getting this truck going.

My86F150

Looks Like I am back to the drawing board. Truck is still running smooth. I got the exhaust leak fixed too. Now I have an issue when I stop and idle for any length of time. The engine starts "searching" for the right rpm. Before I cranked up the idle speed, it would just die when the rpms dropped off, now it catches and keeps going. It sounds like somebody is steadily pressing and then releasing the gas pedal. I also had one incident when I drove it on the highway for about 60 miles and when I slowed down to a stop in the parking lot, it just died. It cranked up, i put gas in it, it started acting like it was out of gas. It cleared up within a minute or two, but certainly made me nervous the rest of the way home. May be related, may not... Lots of new parts on the engine and a new ECM. Occasional low voltage readings for the emission control system, but otherwise no codes being thrown out there.
Any ideas?

Steve83

Bad move. Ignore the diagram & the orifice plugs - read this caption & reset the throttle stop screw (it's NOT an idle speed screw):


(phone app link)

Then put some red threadlocker back on it. IDK why Ford didn't break that screw head off to prevent tampering - it would be a good thing to do, though.

My86F150

I read the link Steve83. It took a while to wade through the details, but I think I can do this. I will need to pick up a tachometer first. As always, making a living comes first. I will update once I've had a chance to get out there and go through these steps. If I interpreted correctly, I should be following procedure B.

Steve83

If you can find one that still works, you can put the factory tach from any '80-86 truck into your cluster:


(phone app link)

Or you can wire up an aftermarket one temporarily or permanently. You could also use almost any OLD tachometer (pre~'00) from the JY temporarily. Some timing lights have a built-in tachometer.

BTW
That fuel valve is made by "Pollack" - not Poldark.


(phone app link)

My86F150

Steve83,
I have looked in my dad's junkyard. He has about a dozen of these vintage Ford trucks sitting out there. None of them had the tach. Amazon advertises one as "rare".
Looks like an aftermarket tachometer is in my future. It is not available otherwise. Thanks for the catch on Poldark. I think that was some show I saw on Netflix. I got the spelling fixed.

Steve83

Well, I have that one for sale, though I don't remember specifically testing if the tach works. It's easy to do, though... So if you don't find an aftermarket one you like, or you don't want to hack one into/onto your dash, e-mail me through my profile here or on SMN. I think it's still missing a "C", but it's certainly closer than it was.