Hello Everyone,

I recently acquired a 1994 F-250 2WD with a 5.0 and E4OD transmission. The day of purchase I drove the truck approximately 30 miles from the seller's house to my home. The truck lacked power and shifting was a bit harsh but it survived the drive home.

Prior to purchase, I used my Innova code reader and discovered both the TPS and O2 sensor were out of range. I replaced both with the battery disconnected, and am now unable to get the truck started. I have spark, fuel pressure is 38 psi while cranking, and I have 12 volts at the injectors with the key in the run position. However, I used a noid light and discovered at the very least that the number 6 cylinder is not receiving a pulse. My understanding is that the injectors are bank fired so it probably means that cylinders 5, 7, and 8 aren't firing either.

I replaced the battery cables today in case a voltage drop was the culprit. The battery terminals were over-torqued at some point and had split which lead me to believe they weren't making a very good connection.

What should I test next?

Thank you in advance.

 

Have you run the KOEO tests and Stored Code (CM) again?

Did you measure the TPS output before and after replacing it?

 

Hi Randy,

The only two codes I am now receiving are 116 and 536. I believe the 116 is due to the engine not reaching operating temperature and am not sure what is causing 536. Since it has to due with the brake system I am assuming it's unrelated.

I did not measure the voltage of the old TPS before removing it. I will measure the voltage of the new one when I get home from work.

Thanks

 

Code 536 is a Key On Engine Running code. That means you did not step on the brake pedal at the right time during the KOER tests. You should start with the Key On Engine Off (KOEO) tests and stored code (CM) display.

The reason I asked about the TPS output is the computer will shut off the injectors during cranking if it senses the throttle is wide open. Given you did not get a code during the KOER tests, it may be good but still suggest to check the output with a meter.

 

Disregard the code 536, My code reader had low batteries and one of the pixels wasn't working. The correct code is 636. I haven't ran any KOER codes yet; only KOEO.

I wasn't able to measure any voltage at the TPS. I was measuring between the black and green wires on the 2V and mV scale. I was using those cheap plastic wire splices you get from Harbor Freight.

I tried starting the truck again and it ran for about 3 seconds than died. I used the reader and returned codes 116 and 636.

The previous owner mentioned that the engine had been replaced at some time. The truck is using the old 15426378 firing order vs. the 13726548 firing order that is on the sticker in the engine compartment. In addition, the spark plugs I replaced were Autolite 2545 because the Autolite 25s I ordered from Rockauto didn't fit.

I'm beginning to wonder if there is a mismatch between the wiring and computer or something. I'm open to any suggestions.

Thanks again.

 

That truck should have MASS air and with the E4OD it would also have SFI PCM.
So NO it is not bank fuel injection.

So the firing order may be wrong as the PCM must be for the same firing order as the Cam.
I would check to see if the PO also changed the PCM.

/

 

I'll pull the PCM and check it tonight. I'm beginning to think there is a wiring harness/PCM mismatch.

Thanks guys.

 

You might also post the calibration number off the drivers side door post "B" pillar so we can check to see if the PCM is the the one it came from the factory with.
Attachment 283763

/

 

Hey Guys,

Below are pictures of the calibration sticker and computer tag. Please let me know if you need anything else. Any help/guidance is greatly appreciated!



Calibration Sticker


Computer Information

 

That is the PCM that came with the truck. It would be for a 1994 5.0L F250 with SFI and E4ODE transmission.

 

I'm glad the computer is correct. What should I do next? Do you think the difference in firing order is the problem? My understanding is that the harness connector is the same for both SD and MAF computers. Is that correct? Is it possible a SD harness was installed?

Thanks again for all the help.

 

You will have to check the wire colors on the injectors with the above diagram to see if it is a MAF harness or not.
Yes the computer plugs for both system will plug into the PCM but they will have different pin outs in the plugs.
The computer you have is for the MAF system also.

 

Thanks for all the help subford. I'll see if I can check the injector colors tonight.

Since the computer is setup for SFI, does that mean it is firing the injectors 1-3-7-2-6-5-4-8? My next guess would be there is a camshaft/injector order mismatch. I still need to figure out why the TPS didn't show any voltage.

One step at a time I guess.

Thanks again.

 

Yes the PCM is firing the injectors in the 1-3-7-2-6-5-4-8 order.

But I do not think this will keep it from starting or running. It just will not be running at the best that it can.
I take it it is still using the MAF sensor. The difference in the wiring could be from the engine plug on.

You ask if it was bank injection or not and that is all I was trying to point out that it is not bank injection when using the NOID light.

Right now you need to check the TPS voltage and recheck with the NOID light.

 

Good news! Injectors 5 through 8 match the diagram so I am assuming 1 through 4 are OK too. That means the harness is MAF, correct? I went ahead and put the computer back in then reconnected the battery.

The bad news is I still do not have any voltage at the TPS. I was measuring the green and black wires in between the harness and the sensor itself.

Where do I go from here?

Thanks again!