Hello all....new here. I have been chasing my F150 for a few weeks now, and do have some fixes I think. I just wanted to get yalls opinion.


When cold...the truck starts great! After it gets to operating temp and I cut if off, then it takes a while to fire. It will turn over just fine, but will not start. When it does start, a lot of black smoke comes out. I am guessing that the ignition control module might be the cause? I have also heard it could be the TPS?


Second, I am having trouble at times with my speedo, and shifting of the E40D trans. I can be driving down the road and the speedo ONLY on the instrument cluster stops working. When it does, then the tranny shifts very hard. I have read where the culprit could be the PSOM in the cluster. Is this valid? Other times, the tranny will shift hard, but the speedo is working...have read that the speed sensor can effect that.


I have planned replacing the speed sensor...when getting the part at the parts store, they gave me a different looking sensor. Their computer shows there are two sensors on my truck, but I can only find the one that is on the rear end diff. But their computer says that is ABS sensor. But I have read that that sensor can do both speed and ABS functions.


I think I am getting close to getting the truck mechanically sound...just these few hang ups are the last of the problems. I just need some expert advice/experience advice. Any help is greatly appreciated!!


Ben

 

What model year truck do you have? Engine?

Knowing the above information will help answer the number of VSS question.

Welcome to FTE!

 

I have a 94 F150 XLT extended cab 4x4 with the 5.0 EFI in it. Thanks for the welcome!

 

Having the E4OD means you only have the sensor on the rear end and it does both jobs as a VSS and a ABS sensor.
The sensor very seldom goes bad but it can collect junk on it to mess with it operation.

When the speedometer stops working does the odometer still show the mileage?



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The difference in sensors may be cruise vs. non-cruise control. I may be wrong, somebody correct me if so.

 

You are wrong. And in the Ford diagrams it is call Speed-Control and NOT cruise control.

The below diagram also applies to the 1994 F-series truck in this thread.


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More than likely a bad ECT or IAT sensor.

Yes it could be the PSOM but more than likely something else.

If the speedometer is working right the the speed sensor (VSS) is working.

The computer is wrong. You only have the one sensor on the rear end.

 

Thanks for all of yalls input. I have replaced the IAT sensor already. When I bought the truck they had a K&N on it, with no factory airbox...the IAT was just out in then engine compartment. Got a factory airbox from the junkyard...got a new IAT sensor, but the problem remains starting it when its warm.


I will get my meter and check out the ABS/VSS sensor and see if it is perhaps bad. I forgot to mention that I did purchase a code reader, and will plan on hooking it up to see what it finds.


More to come....again...thanks for all of yalls input!


Ben

 

The odometer shuts out also...I can hit the top of the dash and it will come back on...kind of like there is a short or a ground issue.

 

What is an ECT SubFord?

 

Remove the instrument cluster, look on the back side at the PSOM components. Frequent failure is bad solder joints.

 

ECT= Engine Coolant Temperature

A picture of it's location from Subford:

 

If that is the case I would not worry about the VSS (ABS) sensor on the rear end right now.

 

https://www.ford-trucks.com/forums/1...s-but-why.html