Constant misfire engine shutdown

[Toolbox57]

Original problem was engine would not start after warm up. Changed plugs and wires then went to coil pack, Mass air flow, IAC valve, fuel pump,filter,Computer from used yard, 3 times. Alternator. Code as of late P0103, we reset it three times and after the third time I reset it while at idle, It just shut off. Every time the battery would be hooked up, it would start and run, 15 volts charging. Maybe the next time we would start it, it would not start easy or if I got it running it would run real rough and smell like it was getting to much gas. I was wiggling wires while it was running and I rapped on the mass air flow sensor and was not able to get it to miss or faulter. Codes thrown in the pass was mass air flow and it was changed and would not work until the computer was changed. Then it would only last for about 100 miles or 5 minutes. I looked at the alternator voltage, and even though it is just under 15 volts, I think it was ok. I am lucky on parts because I am able to get good prices on new and used parts.

 

[Sams01XplrSprt]

do u think its the starter anyways welcome aboard

 

[Toolbox57]

Starter works fine.

 

[BrooklynBay]

Welcome to this forum! It might be a faulty fuel pressure regulator or the engine coolant temperature sensor.

 

[Toolbox57]

I will check out the sensor. I have been looking at the simular threads about this problem and I don't see a lot of completions. At first it was the will not start thing and then it was rough running problem. Then it would shut down. after a short travel. Then when we changed the computer it worked for a couple of days then shut down. Now it just shuts off after a few miles. I will read up on the test procedure of the sensor. The code I got from my auto zone checker was 0103. My code book for explorer doesn't show that code. I will have to find the manufacturer to tell me the code.

 

[BrooklynBay]

According to this list of codes: http://www.fordf150.net/howto/eecvcodes.php it says: P0103 Mass Air Flow circuit High Input. Here is a diagnostic chart for the ECT sensor from # 25 in my list of useful threads:

 

[Toolbox57]

Thanks a Lot, I will give it a measure.

 

[Toolbox57]

WEll today I started the engine and it ran fine. I walked back in toe get my code checker and when I came back out 5 minutes later the engine had shut down. I had the code reader and it read Po103 agin. i reset it and it still did not start. It tried to but didn't. I measered the resistance of the temp sender and it read 4.6 K ohms and the temp of the block read with a digital temp sensor was 160 degrees F. Which makes sense. Any Ideals?

 

[killer7]

This is just an idea, try disconnecting the dongle to the MAS and starting it.

The PCM will use stored values and might idle a tad rough, see if it still shuts off on you and if it gives you that code.

 

[Toolbox57]

Ok, I will try it.

 

[killer7]

How'd it go?

 

[Toolbox57]

Its Fixed!

Well the High Idle p0103 sensor had moisture and dirty connection on the other side of the connection. When that was cleared up that fixed the code problem, but the engine would still idle rough and or just shut off. The Ground connection just below the battery box had corrosion on it causing the computer not to get a good ground. So far thats done the trick.
Thanks for your help!

 

[ThePhoenix]

nice catch....congrats

 

[BrooklynBay]

Thanks for the update!