1999 GMC Yukon Build

justcuz

Explorer
I concur with the others, nice work and a great looking vehicle.

My son had one of these (only a Tahoe) same color combo. We did a little suspension lift and he ran 285/75x16's. Great truck for him and had 285,000 miles on it when he sold it to upgrade to his 2009 Tahoe 4x4.
Only 2 things went wrong with it, the rear axle and the injector spiders.
 

noJeepshere

Adventurer
Slight issue... since the transfer swap, whenever I'm in low range, the ecu doesn't know it's in low range, so it tries to shift at the typical high range points. In other words, left in drive in low range, I effectively only have 1st gear, but I can manually shift it into 2nd. How would I fix that, so that the computer knows when my truck is in low range?

sent from a slablet
 

norcal4x4

New member
Nice build makes me miss my 99 Tahoe. For the 4-low you need to tap into the wire from the 4x4 ecu for low range. The ecu is buried way up on the drivers side real pain to get to. Wire goes to the plug on the front of the transfer case by the front output. Don't remember the colors that are on the transfer case side Though... Two wires one needs to be grounded other comes from the ecu. Here's a pic of the 241 you can see the plug and also the pin out for the plug going to the ecu. Hope this helps. image.jpegimage.jpeg
 

noJeepshere

Adventurer
Nice build makes me miss my 99 Tahoe. For the 4-low you need to tap into the wire from the 4x4 ecu for low range. The ecu is buried way up on the drivers side real pain to get to. Wire goes to the plug on the front of the transfer case by the front output. Don't remember the colors that are on the transfer case side Though... Two wires one needs to be grounded other comes from the ecu. Here's a pic of the 241 you can see the plug and also the pin out for the plug going to the ecu. Hope this helps. View attachment 316975View attachment 316974
This is exactly what I'm looking for, thanks for the help.

sent from a slablet
 

rabbiporkchop

Adventurer
What if I'm not using the 1995 ecu?
My 95 has a 2002 ECU to run the new 5.3, and the 1995 ecu only runs my guage cluster...
Nice build makes me miss my 99 Tahoe. For the 4-low you need to tap into the wire from the 4x4 ecu for low range. The ecu is buried way up on the drivers side real pain to get to. Wire goes to the plug on the front of the transfer case by the front output. Don't remember the colors that are on the transfer case side Though... Two wires one needs to be grounded other comes from the ecu. Here's a pic of the 241 you can see the plug and also the pin out for the plug going to the ecu. Hope this helps. View attachment 316975View attachment 316974
 

noJeepshere

Adventurer
In temps less than 40f it becomes difficult to start, the colder the worse it gets. Bumping the key momentarily, waiting a few seconds then cranking until it runs doesn't help. Sensors are all good, battery is good, no real reason that I can see for it to not want to run. Once the motor is warmed, it'll run beautifully all day, regardless of the outside temp.

The knocking sound you hear once the engine is running is piston slop, at least that's what my mechanic tells me. It's done that for years so I'm not terribly worried about it. The sleeves in the cylinders have become slightly oval shaped, but in temps above 50 and once the motor has warmed up whatever the weather, the noise goes away.

https://youtu.be/_1BvBds-WpA

sent from a slablet
 

Rot Box

Explorer
In temps less than 40f it becomes difficult to start, the colder the worse it gets.

The knocking sound you hear once the engine is running is piston slop, at least that's what my mechanic tells me.

Based on what I'm seeing here it's pretty obvious somebody swapped in a 6.5 diesel as some point :coffeedrink: lol j/k


I've had a few vehicles (gas and diesel) over the years that would drain fuel back into the tank when parked overnight. When you turn the key to the on position can you hear the fuel pump kick on? (some won't pump unless the engine is running/cranking over). Just a thought.
 
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