truck stalls during panic stop

[David Proske]

Twice now my truck has stalled during a white nuckle panic stop. Both times I had to stab the brake to the floor to keep from crashing into a moron. The engine fired right back up both times.

Obviously the engine stalling during this situation when I need power assist the most is not pleasent.

I can think of several possibilities here, but has anyone else expierenced this?

[More Power]

I guess you've got the only truck this has happened to.... :D

Can you kill an idling engine by mashing the brakes, when sitting still?

G load causing an intermittent electrical issue?

MP

[Jim Brzozowski]

David, you have really peaked my interest, since I drive into Houston a lot the number of moron drivers who will swerve into your lane and then jam on the brakes are abundant, they can't seem to figure out the reason you started leaving space is that you may have seen something happening up ahead that they in their low riders can't see.

The only think I can think of at the moment is like MP suggests that you are really loading the power stearing pump when you stand on the brake, and all that oil in the pan has just been pushed by the G force into the front of the pan, causing the front of the crank to be running through the oil. I can't imagine that fuel slosh toward the front of the truck could cause this. Were you full of fuel or almost empty? I assume the pickup for the fuel is near the rear of the tank, but don't know. If it is and you are low on fuel you could be uncovering the fuel pick up and allowing air to get in the line, but I wouldn't think it could shut down the engine that quickly. I have tried running my engine after a fuel filter change without any priming what soever to see how long it will run before the air hits it and its only about 10 seconds of fuel from the filter to the pump at idle. If you are getting air in for the reason stated above, I would think it would take 30 to 50 seconds to stall the engine. Again very curious? How much time did the panic stop take.

[jbplock]

David,

Are you running a lift pump with your Mega filter?

[SLT556]

This sounds like transmission to me. Specifically a torque converter issue.

[madmatt]

the fuel pick up is centrally located in the tank. i'm thinking tranny problem, or maybe(and thats a big maybe) when lifting off the throttle your FP is on the decline and doesn't recover in time to handle the added load of the P/B due to a weak FPR?????

[David Proske]

I am running the mega filter pre oem with no lift pump. I was thinking there may be air being sucked in that way some how. I have 26,000 miles on the filter maybe its time to change it.

I also was thinking maybe a electrical issue being aggravated by the G force of the stop.

madmatt, what do you mean by FPR?

[jbplock]

David,

Since your Mega is pre-oem and the truck starts ok after the stall, it doesn’t seem like there would be a loss of prime from air/vapor in the filter. I had a few stalls with my post oem mega prior to the adding the lift pump and I had to re-prime with the hand pump to get it started.

Also, I believe madmat is referring to the Fuel Pressure Regulator (FPR).

[madmatt]

yeah the fuel press. reg., sorry i'm used to using abv. for everything and just assuming everyone around me knows what I'm talking about. the ladies in the office @ work hate it, but have pretty well got it all translated. also i can't spell worth a hoot so I don't have to do as much when taking these short cuts.

[David Proske]

After changing the mega and oem fuel filters I did a few test stops to see if I could get it to stall. No problems so far. Looks like the mega filter may have been in need of changing for a while :eek:

[precision37]

Just a thought. Maybe the torque converter isn't unlocking quickly enough and it stalls the engine.

[TSimpler]

I had a almost identical problem that got worse and worse. I changed my fuel filter and the problem went away. I didn't believe it when the guys told me to change the filter; but it worked.

Change your filter before anything else.

Trent

[SLT556]

Originally posted by precision37:
Just a thought. Maybe the torque converter isn't unlocking quickly enough and it stalls the engine. I agree. This is what the Allison trannies in the M900 series military trucks were doing. Caused a lot of accidents.