4 Wheel Drive/SUVs: gmc 1500 suburban 5.7 liter with 4wd. 1993


Question
QUESTION: I notice when driveing it hesitates to shift into second.i also notice if i let off of the gas at 3500 rpm and reaply the gas it shifts with out issue.this is very odd to me.is this a product of a normal function of the suv or is there an issue?i just baught this suv used and I'm fixing everything on it.

ANSWER: Richard,

The first thing I would do, is to replace the transmission filter, and fluid.  Many times, when this is done, you can have a "shift kit" installed which will assist in shifting.  I'm assuming that you have quite a few miles on the transmission, due to the year of the vehicle, and is, probably overdue for a fluid change.

This should help the shifting problem.

Carl

---------- FOLLOW-UP ----------

QUESTION: Thank you.i wanted to know as well if there was a way to eliminate throtal positionn sencers as a posibil cause.it has 180 k miles on it and as far as i can find out it has been siting on a lot for a long time.i will swap fluid and filter soon as i get payed and have put in a seal conditioner and stop leak in mainly to restore all the seals..i do not have a check engine light on so i assume all sencers are working as they should.also please explaine this shift kit to mse.can i order this and install it my self?i prefer to ddo my own work and only go toa shop if its beyond my ability.also pleas excuse typos today as my fone is possessed and its writing it own language

Answer
Richard,

I would doubt that the throttle position sensor is your problem. It usually works in conjunction with the air idle control, and maintains a proper idle.  Any of these sensors are fairly easy to replace, with some basic tools, and a good repair manual.  I do most of my own work for a couple of reasons.  One, it helps to be knowledgeable about your rig when something does break, and it can save you a ton of money.

Here is a site that gives a good explanation of a shift kit:
http://www.mistertransmission.com/what-are-shift-kits

Carl