Van running very rich and rough idle

1996 FORD E-SERIES VAN
200,000 MILES • 5.8L • V8 • 2WD • AUTOMATIC
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Van was hard to start when cold, and more difficult to start after reaching normal temperature. Also running high idle and getting terrible mileage, noticeable sooty exhaust.

While looking at the injectors checking for vacuum leaks, I unplugged the MAF sensor and took the air cleaner out of the way,

I forgot to plug it back in before I tried to start it the next time.

The problem with the high idle is gone if I leave the MAF unplugged, if I plug the MAF in it will rev up to the high idle again. Starting is easier and it seems to start after getting warm.

My question is, if I replace the MAF will it fix the problem or is this a sign of another component issue?
Jul 29, 2018 at 6:52 PM
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STRAILER
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This sounds like you have an engine coolant temperature sensor that is not working right. When this sensor goes out it may not trigger a check engine light. Here is a guide to help you see what you are in for when doing the job with a diagram below to show you the location:

https://www.2carpros.com/articles/coolant-temperature-sensor-cts-replacement

Check out the diagrams (below). Please let us know what happens.

Cheers, Ken
Jul 31, 2018 at 1:11 PM
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Thanks Ken,
I switched out the engine coolant temperature sensor and that took care of the problem. MAF, vacuum and fuel delivery was not the problem at all.

Appreciate the help, this site is the best!
Aug 3, 2018 at 1:46 PM
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STRAILER
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Nice work, we are here to help, please use 2CarPros anytime.

Cheers, Ken
Aug 4, 2018 at 11:04 AM