Engine shuts off while driving

[sasso]

Also there is spark and fuel. Pressures are good on crank and fuel is being delivered

 

[blanchard7684]

I would try to see if the issue can be whittled down to steering, brake, or if it has to be both.

 

[viven44]

If it is still under warranty, Tow it back to a different dealer and don’t leave until it’s fixed for good.

As a matter of principle, (and to not give GM an excuse that you tampered) I don’t think anyone should be bothered and take matters into their own hands with a vehicle under factory warranty. If the dealer cannot fix it then pursue remedy with GM, and so on

 

[sasso]

If it is still under warranty, Tow it back to a different dealer and don’t leave until it’s fixed for good.

As a matter of principle, (and to not give GM an excuse that you tampered) I don’t think anyone should be bothered and take matters into their own hands with a vehicle under factory warranty. If the dealer cannot fix it then pursue remedy with GM, and so on

I wish I could take it another dealer. We only have one.

 

[sasso]

The main thing on my mind is, what can cause it not to start right back up. If we figure that out then we can figure out what the problem is.

 

[sasso]

By the way, checked and cleaned all ground points

 

[jfoj]

Questions

1. How many miles on vehicle?
2. Is the battery original?
3. How do you know it has fuel pressure?

A few comments

1. Not sure you are aware but these vehicles have Adaptive Charging Systems. The ECM commands the alternator to turn off and will run the vehicle only on the battery sometimes down to 12.2 Volts before the alternator is turned back on. If the battery is bad, the Voltage could drop too low causing the engine to stall, then the starter could crank the engine, these starters typically have rare earth magnetics and do not need the current the older units needed. If the cranking Voltage is low, modules do not communicate and often you may not get strong/consistent spark and/or injector firing.

I would have the battery checked and/or replaced.

2. You will not always get codes. For example if the FCPM goes bad, the vehicle has no ability to see the output of the FCPM to fuel pump to monitor anything. You would think that maybe the common fuel rail pressure would drop and trigger some sort of low fuel pressure code, but I have never heard anyone state this occured. Maybe is has and nobody has mentioned it. I know you can monitor the high pressure side of the fuel rail, I need to check and see if the low pressure fuel can be monitored.

3. IMHO one of the best trouble shooting tools is Starting Fluid. Go spend the $4 or so to buy a can of Starting Fluid and keep it in the vehicle. Make sure you have what ever is needed to get the air filter box open so you can spray a good 5 count of starting fluid in toward the air intake and then try to start the engine. Usually if the engine starts and dies, you have a fuel problem, if the engine cranks and does not even kick or start you have an ignition problem.

4. Do you have any sort of scan tool? You do not need sometime very advanced, anything is better than nothing. What phone platform are you using? Apple or Android? You can get OBDII apps for your phone and a Bluetooth OBDII interface for typically under $40 and you will always have at least a basic scan tool with you at all times.

 

[sasso]

Questions

1. How many miles on vehicle?
2. Is the battery original?
3. How do you know it has fuel pressure?

A few comments

1. Not sure you are aware but these vehicles have Adaptive Charging Systems. The ECM commands the alternator to turn off and will run the vehicle only on the battery sometimes down to 12.2 Volts before the alternator is turned back on. If the battery is bad, the Voltage could drop too low causing the engine to stall, then the starter could crank the engine, these starters typically have rare earth magnetics and do not need the current the older units needed. If the cranking Voltage is low, modules do not communicate and often you may not get strong/consistent spark and/or injector firing.

I would have the battery checked and/or replaced.

2. You will not always get codes. For example if the FCPM goes bad, the vehicle has no ability to see the output of the FCPM to fuel pump to monitor anything. You would think that maybe the common fuel rail pressure would drop and trigger some sort of low fuel pressure code, but I have never heard anyone state this occured. Maybe is has and nobody has mentioned it. I know you can monitor the high pressure side of the fuel rail, I need to check and see if the low pressure fuel can be monitored.

3. IMHO one of the best trouble shooting tools is Starting Fluid. Go spend the $4 or so to buy a can of Starting Fluid and keep it in the vehicle. Make sure you have what ever is needed to get the air filter box open so you can spray a good 5 count of starting fluid in toward the air intake and then try to start the engine. Usually if the engine starts and dies, you have a fuel problem, if the engine cranks and does not even kick or start you have an ignition problem.

4. Do you have any sort of scan tool? You do not need sometime very advanced, anything is better than nothing. What phone platform are you using? Apple or Android? You can get OBDII apps for your phone and a Bluetooth OBDII interface for typically under $40 and you will always have at least a basic scan tool with you at all times.

1. 36k kms
2. no, second battery, about 5 months old
3. checked it using the scan tool and removed the fuel delivery pipe to see if fuel is flowing during crank.

I tried jump starting it to no success.

we tried starter fluid, did not help

yes, using an advanced scan tool, 0 codes and 0 modules offline

 

[viven44]

I wish I could take it another dealer. We only have one.

Well then, back to the same dealer.

"what can cause it not to start right back up. If we figure that out then we can figure out what the problem is."

With all due respect, the dealer still is best equipped with GM factory manuals to troubleshoot that. If they can't fix it, GM will have to.

Forums and YouTube videos in my experience are best for building up a knowledge base over the years, and the best resource on year models that have been out of warranty for years and has DIY or shop knowledge built up.

I am a Hotrodder myself, tearing apart engines, transmissions, and axles on old trucks, so deep down I love a challenge, but I really mean it here that on something under warranty they are legally obligated to fix this for you for free

 

[blanchard7684]

1. 36k kms
2. no, second battery, about 5 months old
3. checked it using the scan tool and removed the fuel delivery pipe to see if fuel is flowing during crank.

I tried jump starting it to no success.

we tried starter fluid, did not help

yes, using an advanced scan tool, 0 codes and 0 modules offline

So verified spark and fuel.

If you are positive you have fuel delivery up to the injectors then the next thing is making sure the injectors are getting a signal to pulse

Are you able to disconnect an injector to see if it is getting a pulse?

A volt meter or test light of some sort can work