91ls1silverado

So my truck has been shutting off at WOT lately. And last night i showed a friend how it does it. I was peddling through 2nd gear and when i put the pedal to the metal after peddling and it shut off and back fired about 3-4 times, people said they saw flames come out the exhaust for everyback fire. My friend said its a ground problem, anyone have another idea on what it could be before I get into it? Thanks

Old Geezer

iTrader: (3)

Fuel psi is, when this happens?

2000TransAm24

iTrader: (2)

My car did something similar when I messed up the values in my WOT fueling tables that made my injectors max out when I hit WOT. Kinda of doubt this will help you tho

douniasg

iTrader: (10)

Hey did yours actually cut off at wot? Because I have the same problems but this happened after a "tuner" got his hands on my car going in for a dyno. I think something he tweaked in the tune is causing my problems but I flashed my original mail order tune but it's still doing it. Once I go wot it will shut off like I turned off the ignition. I posted the data log on hptuners site the folks there said my maf and injectors are maxed out at 5000rpm. I can understand that but don't get why it didn't do it before taking it to the dyno? I am local too in Maryland if you understand hptuners I can really use some help

91ls1silverado

Don't know the fuel pressure, and i put another ground and voltage seems to be great bur it still shuts off at WOT. Scanned it and nothing came up... Getting really frustrated

douniasg

iTrader: (10)

What are your mods? maybe your maf is maxed out like mine
Any ses codes? I don't have any
I also tried running mine open loop with the 02 sensors disconnected it still shut down and still runs pig rich. Mine will cut off in any gear or speed doesn't matter if it's in first or 3 rd gear as soon as I go wot it dies
Frustrating indeed

91ls1silverado

Cam,LS6 intake,cold air intake, longtubes,ls7 lifters. Got a mail order tune from tunedbyfrost.com. Mine only runs rich at idle but some people say i could be running lean at top end... Mine cuts off 2nd,3rd or 4th.. It started doing this when it started getting cold too....

Ryans99ls1

iTrader: (16)

its a ground problem. If it acts like you turn the ignition off and comes right back to life you have a loose ground or something is arcing.

mine was that i had my catch cans in a way that when the motor hit full boost and "twisted", the catch cans moved just enough to tap the battery and short everything.

A few months ago, i had the ground wire on the back of the heads break off the bolt and the car started acting wild.

91ls1silverado

I'll look around to see if anything is shorting out... Its weird how its only been doing it in the cold...

1970camaroRS

iTrader: (8)

Does the car shut-off completely, as in you have to use the key to restart it? Or does it just break-up, pop and stop accelerating? If so, you probably have something contacting the exhaust and/or you're having false knock-retard. You need a scanner to log what's happening when you drive.

91ls1silverado

It shuts off completely, when it shuts off i try accelerating and the rpms just drop, i have to wait for the rpms to drop completely then start it with the key or pop the clutch... And I'll try that today

1970camaroRS

iTrader: (8)

Sounds like a bad ground somewhere.

91ls1silverado

Okay, so i did some test runs,,when i did my 1st run it shut off at the end of 3rd, i let the rpm drop all the way then i restarted it and it started up fine...after that i did 3 more runs and it didnt shut off...I turned it off for an hour and i decided to do another test pass after having it off for an hour and it shuts off at wot again...

Werewolf SS

iTrader: (3)

Check your battery, make sure it's not rocking and touching the ac condenser bracket or condenser itself and shorting for a moment. Under acceleration it might be sliding back or rocking enough to touch. When the power cuts of it starts to decelerate allowing the battery to slide away. Other things to check are all ground connections like others have said. Since it fires right up we know it's not flooding the engine at wot so fueling doesn't sound like an issue. You most likely have a short somewhere. Check battery, check ground cables, looks at your exhaust and see if any wires are close enough to touch and are burned. Follow the positive cable and look for any spot that the rubber shielding is worn and may be allowing bare wire contact. Do this for the negative side cable also.

Good luck.

91ls1silverado

Checked fuel pressure and its at 58psi.... Still shutting off at WOT...

91ls1silverado

Hooked up my rpm, now i cant even rev it passed 5k with out it shutting off...smh

MontecarloDrag

iTrader: (3)

The crank position sensor may be bad or the reluctor has too much play

01camaroslp

I have the same problem I did change the crankshaft postion sensor,still does the stalling.The car starts fine no issues just when I start going down the block its starts to stalls n dies .my car is a 01 Camaro ss the only mods it has are long tubes .eney ideas

joecar

Also:

The CKP reluctor may be loose (spins on the crank when crank accelerates).

Check battery cables, if positive and negative main cables are routed together in the same convolute tubing, then they may have rubbed thru each other (and short together when acceleration g-force pushes them together)(example of this is LS1 F-car).

91ls1silverado

Alright guys, i finally fixed the problem. It was the crank position sensor connector. It wasn't connected all the way in, i barely pulled the connector and it came right off... So i connected it back in all,the way and put a ziptie so it wouldn't get loose or something. Did 3 test passes and it,all went good thanks everyone!