Hi Everyone,

first post.

I have a 1980 f100 with a 1995 f150 5.0L swap. Manual trans

The motor is a fresh rebuild with zero miles on it. I took everything from a donor 4x4 that was running (bad auto tranny), wiring harness, sensors, upper and lower intake, timing cover etc...
Compression is good across all cylinders.
35 psi at the schrader valve on the fuel rails KOEO. barely drops when cranking.
The swap was easy but getting the new motor to run and idle has been a headache.

The truck is a MAF with a 1994 Mustang pcm with a standard trans (T4M0). I have the original pcm (HUG2) but it is an auto trans pcm. I went with the T4M0 because it is a pcm that is MAF w/o BARO and 5 speed.

I have verified correct wiring for the pins on the pcm with the truck harness. It all matches except the motor has the older cam and firing order. Therefore I switched the pins for the corresponding injectors to match the timing. I have even placed the pins back in the original configuration with no difference.

The motor will fire but stutter and stop. I can not get it to idle properly. The only code that will display is 564. which indicates cooling fan circuit. Of course I have a mechanical fan and this wiring is not there to provide feedback to the pcm.
One problem is that after the code flashes and the second code starts to flash the fuel pump kicks on again causing the test to freeze. The check engine light comes on and stays on or will be off and will not come on again unless I cycle the ignition.

I have played with the dizzy a bit to get the timing as perfect as possible but no difference. Even turning the dizzy slightly makes no difference.

Spark seems to be good on all cylinders and I have good voltage getting to the coil.

I am about to replace the TFI module because that is the only component that is from the donor truck's ignition that is not new other than the coil. I get the rated ohm when measuring with a meter.

New parts.

TM40 ecm rockauto
ECT rockauto
water pump oreillys
dizzy rockauto
battery autozone
platinum spark plugs oreillys
spark plug wires oreillys
dizzy rotor and cap oreillys
radiator rockauto
IAC oreillys
TFI push start grey rockauto

 

Meaning you moved a bunch of pins? If not then no it doesn't match the PCM and you still have some work to do.




A '95 truck motor should have the HO firing order, did the builder swap in some unknown cam?

 

No, I only moved the pins that needed to be moved. I have verified the correct wiring to the pcm as stated in the OP. It was not that many pins. I think 6 wires altogether. (4 injector wires and drivers side HEGO plus the serial VIP data + and - swapped around.)

I used an older cam (brand new but older firing order.) Engine builders usually do not install cams in a short block. It is up to the installer (me) to select a cam and heads to make it a long block. We are not talking about a '95 truck motor but a purpose built short block Both cams will work with both pcms. I have had many f150's and broncos over the years and the 15426378 will work in a 13726548 EFI motor. I am sure there are other threads on here that can back that up.

The wire chart is not helpful. You should check the pinout of 94 & pre-SN95 mustang-thunderbird with 5 speed/MAF. Does not contain a BARO or MAP on pin 45.
It is the reason I selected this pcm. I know the chart is just a mashup of several different pcms to make it easy to locate the wires across many makes and models.

Compare this
Ford Fuel Injection

with this
Ford Fuel Injection

For what it is worth, I am experienced and am not asking novice questions here. Sorry for any ambiguous statements from the OP.

 

Yes with batch fired injectors no wiring changes are necessary but with sequential injection it must match the cams firing order if you want a decent idle, but sounds like you have addressed that.

You're right my chart is comparing an early Mustang with the MAF truck so it's not right for your application.. sorry about that.

The weird PCM behavour while pulling codes is a concern.. could suggest there is somethng wrong with it.

Here's a question does the Sn95 Mustang use a CCD(black) or push start(grey) TFI module? Note the signal differences.. these devices are not directly interchangable.

 

I think you may have found my problem.

I did look into the TFI module but assumed they were all pin compatible.
I have the Black CCD module. Looks like my PCM is wanting the push start version.

From a Ford electrical expert at a local shop:

"The DTC reading issue could be due to a Hardware Limited Operation Strategy"

AKA limp mode.

"Codes can not be read from this state." What say you Forums.

From my reading on HLOS, It is a result from an unrecoverable system issue. For example if there is major electrical issues with the system.

I need to either put my Megasquirt on here or get a J3 chip tuner for the t4m0.

I really appreciate the help on the TFI. I will change it out and see if the engine will start and idle. Plus see if the codes are readable.

 

Push start module ordered.

I was finally able to resolve the HLOS and get the truck to fire and run a bit longer than I previously have.

I found the wiring to the HEGO smashed, so I disconnected the harness and removed the wiring for inspection/repair. Then when I ran the KOEO self test, it completed without any problems.
So for all who have had this weird "codes won't complete" or will not read at all...
Start disconnecting sensors and injectors one by one and performing the self test after each.
Also there is a ford service bulletin that talks about the bad wiring in the harness I am referring to. If I find the FSB I will post here.

Codes are
564 lo speed fan
563 hi speed fan
565 canister purge
558 egr

all of this is disconnected

I am still waiting on a new TFI push start module. I placed the auto trans pcm (HUG2) in the truck and tried to start it. It runs really rough and will not idle still. I think there may be an ignition problem so I will test that. but it seems to run at part throttle. It fluctuates in rpm a lot before it dies.

I am looking into any vacuum problems so I did a minimal vacuum routing by plugging all the ports on the intake tree. except the FPR and the pcv.

As soon as I get a noid light and spark tester (and the TFI module) I will post more results here plus pics.

 

Being that the idle is acting weird I would also confirm that the IAC valve is functioning correctly as I have had issues with them in the past. Also two you may want to make sure that the temperature sensor for the computer itself is functioning as it should or is connected at all as I have had that cause a hunting idle/rich condition all the way up until it was warmed up and at temp.

 

Idle air control was replaced with a new unit. I should have listed that in the OP.

I have also tested it for correct operation and resistance. (not sure if the ecm is operating it correctly.)

Do you know of a good way to test for leaks around the upper and lower intake and vacuum lines? I usually get a big cigar and pull smoke from it using a vacuum pump so that it fills the space allowing for a visual indicator of a leak.

The ECT is new and I tested it using a 5 volt source (from a USB charger) and plunging it in hot water, measuring the resistance. The intake air temperature sensor is original but I tested it by dunking it in hot water while measuring the resistance. The sensors appear to be ok.

So I am leaning towards a timing/ignition or vacuum leak issue. It could possibly be a fuel issue at the injector so I am awaiting a tool to test them.

 

For testing for vacuum leak I'd recommend spraying something like carb cleaner around the intake and listen to hear any changes in how the engine runs, if it changes any while you are doing that then you know for sure you have a gasket leaking for some weird reason.
Also just to be safe if the vacuum test comes up with nothing check the wiring going to various sensors like the coolant temp sensor for breaks or wires touching together and shorting. Hope that helps you some.

 

Please read the entire thread.
All sensors except egr and related are good.
I can not get it to idle or run at all. So spraying the intake down is pointless. Not to mention... Spraying flammables at my engine is not safe and not something I want to do.
How many engines have you burned down by doing that?

Also can I sue you for the advice if I hurt myself?

 

Someone asking for help and then shoots them down is just pointless.

Can you lay your sarcasm on any thicker when others are trying to help?

Wow! Is all I can think of.

 

Sorry if I offended anyone. Sarcasm, what???
You sir are just cluttering this thread even further. Did you even read the thread?

 

No engines have been burned down during these tests, done a few myself and this has been done for years as a good indicator for finding vacuum leaks. So long as you aren't a moron that lays it on super thick then lights a match next to it the worst danger you are in is a bad smell from the carb cleaner. now back on topic I was under the impression you could keep it running via holding the throttle open and then proceed to spray some in the areas around the intake where it connects the two halves as well as around the head to intake areas simply to confirm that there is no leaks. Also for clarification I never meant spray down the intake, I meant on around on the outside of it, because if you have a leak at lets say the base intake gasket where the head and intake meet then the air that would of been sucked in is replace with a fuel and adding the fuel will make the engine run different, most likely it will rev up because it is no longer running lean as can be.
Hope that helps and like the other user said if you really want help or advice lay off the sarcasm and the rude remarks. This a forum, not YouTube.

 

AGAIN, Sorry if I offended someone.

Jeez, do yall take this too seriously or what. Should not I be the one to judge if it helps or not.

No I am not a moron but spraying carb cleaner at a stumbling engine is just setting myself up for failure. If it would partially idle and I would not have to jog the throttle to attempt to keep it running I would spray it. (Hmm maybe with my fourth hand I can hold the carb cleaner while goosing the throttle and spraying the intake.) Now that's sarcasm....
I have done this before and it is crazy dangerous. Ask any ASE mechanic. Shade tree much?
I do appreciate the responses but like any opening post on this forum looking for help, the poster is looking for feedback that fits them, not someone else......
Spraying the intake and lines won't work for me.

 

The only other thing I can think off is to check the PCM for blown or bloated caps inside of it if you have not and even grab another good maunel trans PCM just to confirm there is not some break in the board that you'd never see unless you stuck it under a microscope and checked every trace in the board. If everything else from the sensors to the TFI being correct and the pip in proper functional order that is the only thing I can come up with off the top of my head, assuming this is electrically based issue. No worry's sir we all here mean well its just some of us take some comments the wrong way, especially when the morning coffee has barely set in yet .