# 1989 GMC Jimmy stumble

**URL:** <https://community.cartalk.com/t/1989-gmc-jimmy-stumble/114019>\
**Category:** Maintenance/Repairs\
**Tags:** jimmy, gmc\
**Created:** [March 19, 2018, 8:45pm UTC](https://community.cartalk.com/t/1989-gmc-jimmy-stumble/114019 "2018-03-19T20:45:11Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![BobLawrence](https://avatars.discourse-cdn.com/v4/letter/b/f19dbf/32.png) [@BobLawrence](https://community.cartalk.com/u/BobLawrence)\
**Post date:** [March 19, 2018, 8:45pm UTC](https://community.cartalk.com/t/1989-gmc-jimmy-stumble/114019/1 "2018-03-19T20:45:11Z")

</div>

I bought this new and have always kept it in good shape and serviced at proper intervals. It now has 140,000 miles and runs great - except for a “once in a while” problem.  
When taking off from a stop, it will stumble just for a nano second. Before I can even raise my foot off the throttle, it takes off! Then it won’t do it again for weeks or even months.  
It has a new fuel pump and the throttle body injector has been worked on. In desperation the mechanic replaced the distributor. That seemed to solve it for about 6 months. Now it is back to a very random occurrence, always when taking off from a stop - never when going down the road.

---

<div class="post-metadata">

**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\
**Post date:** [March 19, 2018, 8:54pm UTC](https://community.cartalk.com/t/1989-gmc-jimmy-stumble/114019/2 "2018-03-19T20:54:12Z")

</div>

The problem might be due to a faulty MAP sensor.

[https://www.rockauto.com/en/moreinfo.php?pk=3248118&cc=1156519&jsn=445](https://www.rockauto.com/en/moreinfo.php?pk=3248118&cc=1156519&jsn=445)

The MAP sensor took the place of the accelerator pump and the vacuum advance when engines had carburetors and distributors.

Tester