1998 Z71 Stalls when coasting downhill

[Z71Hobbs]

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?

The k1500 did come as an option for a 6.5. Ive owned two k1500 6.5 that were equipped with a 6.5. Appears to be more of a southern us thing.

 

[Nad_Yvalhosert]

The k1500 did come as an option for a 6.5. Ive owned two k1500 6.5 that were equipped with a 6.5. Appears to be more of a southern us thing.

Yes, I've heard of the 1500 diesel, just never seen in person, the combination of Diesel, 4x4, half ton, and Z71. Never said it didn't exist.

 

[Hbomb]

WHAT ENGINE? Diesel? V-6?

Sorry, 5.7 liter

 

[Schurkey]

Verify fuel pressure.

Connect a scan tool, look at all the sensors--but especially coolant temperature, MAP, TPS, and make sure the IAC can actually control the idle speed.

Make sure there are no "codes" or "pending codes" waiting to surprise you.

How long has it been since this thing got a proper tune-up--spark plugs, plug wires, cap 'n' rotor, throttle body and IAC passage cleaning, fuel filter, air filter, etc?

 

[Supercharged111]

Yes, I've heard of the 1500 diesel, just never seen in person, the combination of Diesel, 4x4, half ton, and Z71. Never said it didn't exist.

I passed one up when I bought my 1500. Didn't realize what a unicorn it was or would become back then. Still glad I got the truck I have though.

 

[Dariusz Salomon]

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?

I had similar sensation in my 99 z71-pretty worrying if you ask me. I always kept my tank just with a quarter of gasoline-as I have mine converted to propane-but with my setup it always starts on gasoline until it reaches around 35 deg engine temp . Then once I filled it up all the way and it stopped stalling. So I assume something to do with the fuel pump not liking the level to be too low. Now I always keep it full.

 

[stutaeng]

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.

I think those also had the heavy duty transmission as well, from the heavier trucks...at least the turbo ones did.

 

[Hbomb]

Verify fuel pressure.

Connect a scan tool, look at all the sensors--but especially coolant temperature, MAP, TPS, and make sure the IAC can actually control the idle speed.

Make sure there are no "codes" or "pending codes" waiting to surprise you.

How long has it been since this thing got a proper tune-up--spark plugs, plug wires, cap 'n' rotor, throttle body and IAC passage cleaning, fuel filter, air filter, etc?

Ok, thanks.

im not really sure about proper tune up items other than the air filter, as I just bought it a month ago.

 

[Dariusz Salomon]

Ok, thanks.

im not really sure about proper tune up items other than the air filter, as I just bought it a month ago.

Try my solution first-unless you always have her filled up. That's certainly easiest of tests.