Reverse stall out

[Poopyface]

Truck stalls out when put in reverse. Goes forward just fine. Backed down the driveway earlier this morning no problem. I am scratching my head here.

98 k2500 pickup 5.7

 

[yozsi]

Is it everytime? If you give it some more rpms does it not stall?

 

[AgitatedPancake]

Just to confirm, check engine light? Also, any signs of a failing brake booster creating a vac leak?

 

[Poopyface]

I am at work at the moment so I can't mess with it till 8 but it stalls as soon as it's put into reverse. Tried twice. No check engine light.

 

[YotaAtieToo]

My buddy bought an 06 dodge that 1st gear had basically welded itself into gear. So putting in reverse was like a trans brake. Sounds like that could be what's going on

 

[Clb]

Vacuum leak...
Or the "bring me to the stealership" weasels

 

[larboc]

Low on gas? Sloshes away from the pump in reverse?
I'd start by checking fuel pressure.

 

[engineerjoe]

How does the truck idle? normal and stable? hunts a little?

Idle air control valve could cause a low idle, and when you shift into reverse, it drops the RPM's enough to stall

 

[Sceep]

Carvid-19, or vaccination side effect.

 

[KarlVP]

Drum brakes full of mud?

 

[SomeGuyFromOlympia]

98, drum brakes?

I had a dozer that did something like that. Brake lining came loose and would jam going backwards

hopefully it is just something simple like that

 

[Projectjunkie]

I've seen fwd cars with cracked intake tubes open up when the engine rocked, skew the AF ratio and die, don't rule out something similar, or a damaged wiring harness doing the same

 

[Here4memes]

I had a 86 Ford F150 with a 300 six that would backfire and stumble in reverse. Rebuilt the carb several times thinking that was it. Never figured it out. Sold the M-F just because of it.

I like the idea of jacking the front and then the rear up and see how the wheels spin forward and backwards. I imagine it could even be a bearing issue?

 

[Redtruggy]

Auto??
One way sprag in trans ****ed up.

 

[ConwayMuddy]

Just to confirm, check engine light? Also, any signs of a failing brake booster creating a vac leak?

How does one test this? 91 gmc Burb with 5.7 here, push the brake pedal and got a pshooom sound, could also hear a sucky noise under hood when it actually ran.

 

[AgitatedPancake]

Hissing or squealing when you hit/hold the brakes is a good indication that the booster is failed and creating an open vacuum leak. If the idle falters when you hit the brakes is another good indication. I've admittedly been driving with a bad booster for a while, and I can make it squeal on demand.

The reason I brought it up here, is you usually mash the brakes right when you shift into reverse. So if hitting the brakes causes a vacuum leak that makes the engine stumble, paired at the same time with the standard burble shifting between gears it can stall an engine

 

[M92PV4U]

I don't know, but I have a '93 1ton 4l80e that feels like the brakes are dragging when you drive it with the selector in 1st.

 

[[486]]

How does one test this? 91 gmc Burb with 5.7 here, push the brake pedal and got a pshooom sound, could also hear a sucky noise under hood when it actually ran.

plug the **** off or vise grip the hose

it runs different? hey, it were leek

 

[arse_sidewards]

An auto shouldn't be stalling more or less ever unless something is ****ed up with the engine side of things.

I also suggest looking for vacuum leaks.

 

[DMG]

Wiggle all the wires/cables/etc you can find And see if one of them does it.

 

[[486]]

boosted line pressure causing a leak into the TCC circuit?
converter should keep it decoupled from anything the trans is doing well enough to keep the engine runnning otherwise

 

[Ranchtruck]

Check all the hose and connection between the throttle body and the mass airflow sensor on the air filter box. If you have a crack or leak that air can get in it will loose the mass airflow reading and stall.

 

[Poopyface]

Thanks for the suggestions. I drove it home last night and could not get it to stall again when I shifted into reverse.

Tank was half full. It idles fine but the rpms have been fluctuating when coasting downhill. It has done that since I bought it.

Brakes have been a bit strange lately so I will check for vacuum leaks and let the girl listen. No mud on or in this truck unfortunately.

Will check the wiring as well since we found nice nests in the 4runner when we cleaned it out.

 

[larboc]

Thanks for the suggestions. I drove it home last night and could not get it to stall again when I shifted into reverse.

Tank was half full. It idles fine but the rpms have been fluctuating when coasting downhill. It has done that since I bought it.

Brakes have been a bit strange lately so I will check for vacuum leaks and let the girl listen. No mud on or in this truck unfortunately.

Will check the wiring as well since we found nice nests in the 4runner when we cleaned it out.

Might try putting the t-case in neutral and see if it continues to stall next time it's having a fit.

Does it still have the original injector spider BS or has it been swapped to multiport injectors? I've never seen an SBC or 4.3 with that injector nonsense that ran well.