97 Suburban wont run right in gear

This is my first time posting here. I have been reading for a long time but never posted. I have a 97 suburban k1500 with a 5.7 that will run fine in park. It swear it idles a little rough but the tach doesnt show it so maby I'm nuts. Anyway when I put it in gear and go for a drive it gets up to around 2000 to 3000 rpm and just acts dogs down. It has no power at all until Ilet off the gas then it will pick up. I have tuned it up butthat didnt do any good. I had it die on me a few times about 1 month ago. I barely made it home just kept dieing every 5 minutes. It wouldnt run at all the rest of the night. Got in it the next morning and it ran perfe3ct for about 20 minutes then right back to nothing over 2500 rpm. In have a scan tool for my laptop so if I can get any info to help I will be glad to. Thanks for all the help you all have given.

If you can pull the codes that would help a great deal. Otherwise there could be a number of things to check.
Post your codes and someone will help you through this.

The main problem is that it isnt putting out any codes at all. I did find out that it may have somthing to do with the tranny. Its not wanting to kickdown and its not wanting to shift when you punch it. I did get it to rev up to about 4200 on then highway but In had to coax it. I've been reading trying to figure out what makes the 4l60e decide when to shift and kickdown. Thank you for your help I appreciate it.

The main problem is that it isnt putting out any codes at all. I did find out that it may have somthing to do with the tranny. Its not wanting to kickdown and its not wanting to shift when you punch it. I did get it to rev up to about 4200 on then highway but In had to coax it. I've been reading trying to figure out what makes the 4l60e decide when to shift and kickdown. Thank you for your help I appreciate it.


I would check fuel pressures ,,,,find out what your vehicle requires for pressure and with a pressure gauge drive around to see if its working correctly....

no dtc,,,,intermittent failures ,,,,usually fuel supply,,,most likely electrical connections,fuel relay, fuel pump motor ...ground conections..

It sounds as if you are stuggling with a power (engine) problem. It is quite possible that you have exhaust restriction. You might want to try and loosen the exhaust before the catylist and test drive. Also as stated in the previous post, check fuel pressure.

Other than that, the 4l60e transmission counts on the ECM to signal the shift solenoids. Earlier models used a vacuum modulator to correct the shift points and if fluid is present on the vacuum side the unit is no good. A vacuum leak to this would also cause problems. On your vehicle this is probably not the case but worth a quick look.

A scan tool should be used to test the shift solenoids for proper function.

This may seem trivial but is the fluid full? Check in park when hot. Is the fluid a nice pink or red color. If not perhaps its time for a fluid and filter change. Do not get a flush and fill without the filter change. I have seen the filter/pickup come loose on these which would cause problems as well.