1998 Z71 Stalls when coasting downhill

[Hbomb]

I’ve noticed my 1998 Z71 will stall when coasting downhill. Seems to happen when engine is somewhat cold. Rpms go to nothing, power steering and brakes quit, but I am able to come to a stop put in a park and start right back up.

Does not happen when I’m giving it gas. Any thoughts? Maybe get a tuneup to start?

 

[Erik the Awful]

You're going to have to do some diagnosis. Being that it only happens when cold, I'd suspect a fuel mixture problem, specifically running rich. I'd start by checking O2 sensor voltage and make sure it swings at least 7 times in 10 seconds. EDIT: ...but I don't think the computer actually looks at the O2 sensor until it's warmed up.

Check for dead squirrels and acorns in the air filter box. If you haven't done a tune-up in a while, definitely start there.

 

[Schurkey]

WHAT ENGINE? Diesel? V-6?

 

[Nad_Yvalhosert]

WHAT ENGINE? Diesel? V-6?

Had a good laugh, never seen a V6 Z71.
Cant recall a diesel Z71 either.
Vast majority of Z71's were Silverado package and 5.7. Maybe a couple 5.0's...
Never seen a 7.4 in a K1500
Never seen a Z71 in a 2500
I have yet to see a Cheyenne, non power window, non A/C truck with Z71
But a good laugh anyway. Thanks!

O.P. we need more info, you might even have to be using a scantool when it happens.
Question: how much fuel is in the tank, and how steep of a downhill?

 

[df2x4]

Cant recall a diesel Z71 either.

Those do exist. @Z71Hobbs has one.

 

[Nad_Yvalhosert]

Those do exist. @Z71Hobbs has one.

Unicorns do exist, huh?

 

[Schurkey]

The truck I robbed the rear axle and driveshaft off of last week was a Z71 Diesel. I figure the diesel was why it had a 9.5" six-lug axle instead of the pathetic 8.5" axle.

 

[HotWheelsBurban]

You're going to have to do some diagnosis. Being that it only happens when cold, I'd suspect a fuel mixture problem, specifically running rich. I'd start by checking O2 sensor voltage and make sure it swings at least 7 times in 10 seconds. EDIT: ...but I don't think the computer actually looks at the O2 sensor until it's warmed up.

Check for dead squirrels and acorns in the air filter box. If you haven't done a tune-up in a while, definitely start there.

You saw that Avalanche the squirrel was using for his pantry too, huh? I couldn't believe it, wouldn't have if there hadn't been pictures!

 

[Erik the Awful]

Decades ago I had a customer bring in a Maxima that was running poorly. I emptied an entire airbox full of acorns. It didn't take an internet meme to wake me up to that truth.

 

[Erin]

Maybe a couple 5.0's.

My uncle has one.