My GMC Jimmy feels like its missing.?

[allenh2_05_90]

When i get on the interstate and driving at higher speeds it seems to do it more. I was at the store the other day parked and the RPM Gauge would jump up to 2000 and go down toward 0 and feels like its cutting off. It has cut off twice but started right back up. I did and oil change and put in a new fuel filter and drove 400 miles. It missed some. I got home and then yesterday i was driving and it missed and cut off and won't come back on.
1997 gmc jimmy 4.3L Vortec

 

[Michael S]

Your vehicle needs a tune up.

 

[wander80]

More info please. What year, engine? Is it carburated or fuel injected?It sounds like something in the fuel or emissions systems but need more info

 

[Jesse]

yeah its probably missing, i think you can go to autozone and they will scan it for free, you might need a new spark plug wire, my car misfired because of a broken wire that looked completely fine

 

[Molson02536]

When i get on the interstate and driving at higher speeds it seems to do it more. I was at the store the other day parked and the RPM Gauge would jump up to 2000 and go down toward 0 and feels like its cutting off. It has cut off twice but started right back up. I did and oil change and put in a new fuel filter and drove 400 miles. It missed some. I got home and then yesterday i was driving and it missed and cut off and won't come back on.
1997 gmc jimmy 4.3L Vortec

Your ICM (Ignition control module) sounds like it's going bad and will need to be replaced. This is the electronic control for the ignition system. The module receives a signal from a magnetic pickup or Hall effect sensor in the distributor. The module uses this signal to open and close the ground circuit to the ignition coil to fire the spark plugs.

The ignition module itself may be located inside the distributor, on the distributor housing. The ICM also control timing advance and retard. If a module goes bad, it usually goes completely dead. The engine won't run because there's no trigger voltage to the ignition coil.

The other thing also to keep in mind is that it's common for the breather screen at the bottom of the distributor to get dirty which will cause poor ventilation causing condensation. The condensation will promote corrosion to the wire leads to the ICM and in turn will cause what you have described.

Long story short. Inspect your ICM and have it tested, Auto Zone or Napa can test the ICM free of charge.