1993 Suburban TBI problem

[MikesZ06]

I have a 1993 2500 4x4, auto, Suburban with a 5.7 TBI motor. The truck runs great except it hesitates when you put it gear when it's cold. This only happens once and then the truck runs fine. The truck has 70k miles and I have recently changed, cap/rotor, plugs, fuel filter.

 

Thanks

[citydriver]

I have a 1993 2500 4x4, auto, Suburban with a 5.7 TBI motor.  The truck runs great except it hesitates when you put it gear when it's cold.  This only happens once and then the truck runs fine.  The truck has 70k miles and I have recently changed, cap/rotor, plugs, fuel filter.

 

Thanks

 

<{POST_SNAPBACK}>

 

 

Does it have any problems starting when its cold?

Does the CHECK ENGINE light come on at all?

Do you know if the Coolant Temp. Sensor or O2 sensor have ever been checked/replaced?

Does it do this every time you start it or just in the morning?

Just a few questions that popped into my head as I read your post

[MikesZ06]

I have a 1993 2500 4x4, auto, Suburban with a 5.7 TBI motor.  The truck runs great except it hesitates when you put it gear when it's cold.  This only happens once and then the truck runs fine.  The truck has 70k miles and I have recently changed, cap/rotor, plugs, fuel filter.

 

Thanks

 

<{POST_SNAPBACK}>

 

 

Does it have any problems starting when its cold?

Does the CHECK ENGINE light come on at all?

Do you know if the Coolant Temp. Sensor or O2 sensor have ever been checked/replaced?

Does it do this every time you start it or just in the morning?

Just a few questions that popped into my head as I read your post

 

<{POST_SNAPBACK}>

 

 

 

 

Thanks for your help. To answer your questions, the truck starts fine and idles fine in the cold. It will hesitate only when you put it in gear and move it for the first time. It will not do it again untill the truck has sat for a couple of hours.

 

I let the truck idle 10 min once before I tried to move it and it still stumbled. I have not changed the 02 or coolent temp sensors. The check engine light has never come on. Thanks again for you help.

[citydriver]

Thanks for your help.  To answer your questions, the truck starts fine and idles fine in the cold.  It will hesitate only when you put it in gear and move it for the first time.  It will not do it again untill the truck has sat for a couple of hours. 

 

I let the truck idle 10 min once before I tried to move it and it still stumbled.  I  have not changed the 02 or coolent temp sensors.  The check engine light has never come on.  Thanks again for you help.

 

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Well then, you can pretty much rule out the Coolant Temp.(CTS) and O2 Sensors...if it only does this once after a cold start....a bad CTS may make it hard to start or make the engine run real rich if it were going bad,and the O2 would mostly affect it after it warmed up and the computer went into closed loop...

Does it only do this when you put it into Drive, or will it stumble when you Goose it in Park?

 

Does it puff smoke when it does this? If so, can you tell what color the smoke is?

Black= running rich Light blue= oil possibly seeping past valve seals (this is some what normal for 5.7L from '87-'94) OR White smoke w/slight sweet smell to it= coolant this may be caused by a intake gasket leak or head gasket (worse case) Note: these are just thoughts, I'm not trying to scare you

 

It could also just be that your IAC (Idle Air Control) motor is sticking and just reacts slow....You could try cleaning the Throttle Body with Carb. cleaner to clean off the varnish or sludge that sometimes builds up on the IAC and throttle plates.

Another possibility may be that it could be a valve sticking in the tranny....Does it stumble in reverse also?

 

These are all just things I would check for....I hope this helps some