Insanely hard upshifting all of a sudden

[Derick]

Tech called me and installed a known good purge valve and it isn't blowing the fuse anymore. However it's still shifting hard. So, we're going to remove my aftermarket maf sensor and install a Delco. That's on order and will be here tomorrow. Of course my dumbass tossed the original.

 

[Derick]

If I didnt have bad luck, I'd have no luck..... shop put on the new OEM MAF sensor and well, with a good purge valve it runs well, and shifts properly. But now, there must be a defect in the new sensor, because the temp sensor portion of it is reading like 200+ degrees. While the aftermarket sensor is reading a proper 93 degrees. Soooooo, nother sensor ordered to replace this defective assembly.

What pisses me off is this. I sat on the burb for a week, had I thought to get a damn OEM MAF, they are 75 bucks at rock auto. I paid like 62 for this after market one, and 160 for the delco at the dealer...

 

[Derick]

Welp we're calling this issue done.

Being at IBM for 7 years, we have a 5 'whys' Root Cause Analysis.

Problem: Transmission is hard shifting

Why 1: The MAF sensor has no power
Why 2: The fuse that powers the MAF has blown
Why 3: The circuit is shared with the evap purge valve
Why 4: The purge valve is shorted or overloading
Why 5: The purge valve is bad and requires repalcement

So, the root cause in this particular problem of hard shifting in ALL upshifts, was the evap purge valve. The tech has a known good valve on it, and all is working great.

My subjective commentary: I'm an idiot. Dont be like me. I normally dont like throwing parts at a problem, but here I did. I threw a new MAF and a new MAP sensor. Being that the circuit wasnt getting power, it solved nothing. Turns out the aftermarket MAFs are 50/50 in success anyhow. Because I *thought* I threw away the old MAF at OReillys when I bought the new one, I ended up buying a new delco MAF at the stealership for a brisk 180 dollah. So, my total repair cost on this was 480 dollars. I could have cut that in half had I remembered that I had the original MAF and the tech could have tested it with the newish purge valve. At the end of the day, I'm not mad, the MAF is 160k miles and 13 years old. These things dont last forever, and now the truck with the new delco MAF is shifting better than it ever has before under my watch. The tech gave me some good news that he was very satisfied with the rebuild of the trans and he feels it will serve me well.

 

[Geotrash]

Welp we're calling this issue done.

Thanks for following up here. I'm about to throw a new MAF in my '07. I bought a Dorman one specifically because it uses a different technology that's advertised to solve the shortcomings of others that use an OEM design. What brand gave you the headaches?

 

[Derick]

Thanks for following up here. I'm about to throw a new MAF in my '07. I bought a Dorman one specifically because it uses a different technology that's advertised to solve the shortcomings of others that use an OEM design. What brand gave you the headaches?

' blue streak ' from O'Reilly auto.

I gotta ask, why not oem? Oem mafs are 75 bucks on rock auto and about 13 bucks more than that blue streak from O'Reilly.... Sooo... Get it there if you can and you won't have to drop stealership prices.

 

[Tonyrodz]

' blue streak ' from O'Reilly auto.

I gotta ask, why not oem? Oem mafs are 75 bucks on rock auto and about 13 bucks more than that blue streak from O'Reilly.... Sooo... Get it there if you can and you won't have to drop stealership prices.

Nothing like oem tho.