2002 Tahoe starts great when cold but will not right after driving

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Gossamer

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My 2002 5.3 Tahoe (owned since 2017, fuel pump never changed) starts up after sitting 20 minutes or longer after driving but will not right after driving. No loss or boggy feeling while driving however. It has been developing a difficult to start issue (compared to what it usually does....I have always just bumped it to start it, but now it 'sometimes' takes 1 to 2 extra bumps to start it)
Fuel pump about to go out or possibly something else?
Thanks
 
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nonickatall

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I had that once on a Chrysler Lebaron convertible.

There were injectors bad. But you should also check o2 sensors and mass airflow sensor. As well ingnition coils can be bad. When an engine runs cold, but not warm, its nostly some sensor or electrical issues.

Does you temperature gauge shows the correct engine temperature? Because, the sensor for the gauge is also the sensor for the ecm.

It is not typical for a problem with the fuel pump.
 
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Gossamer

Gossamer

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I had that once on a Chrysler Lebaron convertible.

There were injectors bad. But you should also check o2 sensors and mass airflow sensor. As well ingnition coils can be bad. When an engine runs cold, but not warm, its nostly some sensor or electrical issues.

Does you temperature gauge shows the correct engine temperature? Because, the sensor for the gauge is also the sensor for the ecm.

It is not typical for a problem with the fuel pump.
All coils are functioning properly. MAF sensor is kept clean and that doesn't keep it from starting even if it was out, it would just run rough. Engine temp is normal.
 
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nonickatall

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All coils are functioning properly. MAF sensor is kept clean and that doesn't keep it from starting even if it was out, it would just run rough. Engine temp is normal.
With components like MAF, coils, injectors even controllers like ecm, can sometimes be a proplem that they work when cold, but due to a little crack in a coil or a bad solder, they quit work when warm.

I had that several times in my mecanical life.

It is unlikely that you engine has a mecanical problem. So it comes from some electrical component.

So lets start logical.

When the engine not runs, can you read out for error codes and live data? Can you check the fuel pressur with a gauge?
 
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Gossamer

Gossamer

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With components like MAF, coils, injectors even controllers like ecm, can sometimes be a proplem that they work when cold, but due to a little crack in a coil or a bad solder, they quit work when warm.

I had that several times in my mecanical life.

It is unlikely that you engine has a mecanical problem. So it comes from some electrical component.

So lets start logical.

When the engine not runs, can you read out for error codes and live data? Can you check the fuel pressur with a gauge?
Yes, the Camshaft Position Sensor shows as an error code. Cleared it and it did come back up again. Would that create a hard starting issue? Runs great and smooth once it starts. Also, it doesn't always have the hard starting issue.
 

mattbta

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Yes, the Camshaft Position Sensor shows as an error code. Cleared it and it did come back up again. Would that create a hard starting issue? Runs great and smooth once it starts. Also, it doesn't always have the hard starting issue.
Is it original or aftermarket? Aftermarket are junk - these trucks only like OEM for those.
Suggest doing a CASE relearn first.

Does it act like this? (Aftermarket cam sensor, installed OEM and now no probs)
 
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Gossamer

Gossamer

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Is it original or aftermarket? Aftermarket are junk - these trucks only like OEM for those.
Suggest doing a CASE relearn first.

Does it act like this? (Aftermarket cam sensor, installed OEM and now no probs)
Exactly, when it does it....which is about 30% of the time.
I am pretty sure it may be the original sensor. I have owned the Tahoe since 2017 and have never changed it.
 

nonickatall

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Yes, the Camshaft Position Sensor shows as an error code. Cleared it and it did come back up again. Would that create a hard starting issue? Runs great and smooth once it starts. Also, it doesn't always have the hard starting issue.
Sure if the camshaft position sensor is not available, your engine don't know when to inject and when to ignite..
 

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