Mystery pigtail brown and brown/white stripe

[east302]

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PDFs of the GM manuals (most years) can be downloaded here:

88-98 Service Manuals

Over the years I have collected a bunch of GM service literature. Links to PDF Scans of service and STG manuals and a links to the Parts manuals. You'll need the FREE Adobe Acrobat reader to open these files. Get it directly from Adobe here {http://get.adobe.com/reader/} If you're not...

www.gmt400.com

 

[iamtherealJayy]

The air filter and intake tube were off the engine at the time, I know the maf is in that and was unplugged along with the other sensor in the intake tube. Where is the MAP located on this engine?

 

[east302]

Top of the intake near the coil

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[iamtherealJayy]

Everythint there is plugged in, the map is a new code. Could that cause the running rough and smells like fuel

 

[east302]

It could, throwing off the computer’s fuel calculations. I would resolve those codes first though it sounds like the MAF code may be gone now if it was just unplugged earlier.

 

[iamtherealJayy]

The truck did run fine prior to valve adjustment, but I didn’t remove anything the valve covers were already removed. I’ll get the intake back on to try and remove the codes

 

[GoToGuy]

The air filter and intake tube were off the engine at the time, I know the maf is in that and was unplugged along with the other sensor in the intake tube. Where is the MAP located on this engine?

I gave you the diagrams, did you look at them?

 

[someotherguy]

A bad signal from the MAP sensor will absolutely cause poor running due to rich fuel mixture.

The two sensors in the intake tube are the MAF and IAT

Richard

 

[iamtherealJayy]

@GoToGuy yes, but this is my first modernish? 350. I’m used to carbs and I’ve got one tbi that’s gave me trouble since I got it. I’ll look into testing the map tonight

 

[iamtherealJayy]

Truck continuing to run rough, smooths put with throttle but no completely, backfires, misses etc. replaced map and still get code po108. Unplug map while running and get po107. Faulty new map sensor? Or do I just need to bite the bullet and back off the valves some?