Bear with me as I try to explain what is going on. Keep in mind that this doesnt happen all the time. Usually when the truck is cold but not always then.. What is happening is when I first pull out it seem to totally skip 1st gear and go into second which creates a total loss of power. It also will not kick into overdrive when it does this so running 65mh the rpms are sitting above 2.5. Also when this happens when you are slower the transmission will jump back and forth from higher to lower gears causing an almost stuttering effect. The tach will go up and down as it does it. Their are two things that seem to fix it. 1 is if I drive for a bit at around 60mph then it will suddenly kick into overdrive and then things will be fine and it will cycle through the gears normally and the second thing is to start out from a standstill pretty fast so that it runs through first gear pretty tight. that works as well.

Just trying to figure out what might be causing this issue. Hope I explained it well enough so that you guys understand what it is doing. Thanks for any comments on what it may be

Chad

98 Blazer ZR2

 

Have you changed the transmission fluid & filter lately?
(Should be done every 36K miles)
Does the SES light work?
Does it come on or flash while driving?
Are there any DTC's in memory?
If so, what are they and what order are they in?

 

The SES light does work and is not currently on. I will get the Transmission Fluid and Filter Changed tomorrow and swing by AutoZone and see if they still pull Codes. If they do I will report back with what I find.. And could it be an ECM problem?

 

Without any DTC's in memory or the SES light on, it's doubtful the PCM is causing the problem.

 

I have this same problem, though mine doesnt skip 1st gear, it shifts normally but wont go into OD until after a few miles, I don't know if the transmission just has to warm up or something, the fluids are fine. Other times it wont kick into OD at all and I will be on the highway running 2.5k+ rpms

 

I had the transmission flushed and have only driven it once since then. It shifted fine and didnt have any of the former symptoms. I will keep an eye on it and give a better update in a few days. Thanks for the suggestions guys. Its really appreciated.

 

Transmission flushed, but did they replace the filter after the flush?