Okay... I have a 1993 GMC Jimmy... 4.3L Vortec, W in the vin number. First off, I have spent way too much time and money into this piece of junk and now I just can't afford not to fix it. I'll go ahead and list most of the things I've had done and then tell you the problem I have now:

-Had new spark plugs, wires, oil change, etc done when I first got it.
-Had to get all four ball joints replaced
-New brakes, new tires... new rotor for the front driver side
-Oil pump went bad so I had a new oil pump and oil sending unit put in
-Had to have the tranmission rebuilt
-Several sensors and valves replaced (idle air control valve, map sensor, egr valve, pcv valve, blah blah blah)
-Had to get a new muffler and tailpipe because a vacuum plate had collapsed??? (not sure about that one, but that's what I was told)
-Also had to get a new spider injector because mine had gone bad apparently

Now my problem that still remains. Sometimes the Jimmy will run fine, but most of the times it won't. When I'm driving in the city... it never runs fine at all. When I drive on the highway, the Jimmy will run fine for about 10 miles or so (give or take). My service engine light comes on and immediately there is a lot of resistance and pressure (you can hear a loud humming noise) when I'm trying to give the Jimmy gas to accelerate. It usually happens after I've been driving up to speed, then slow down to just around 40 mph or below. The kick to it is when I come to a stop... the Jimmy doesn't really want to stop and it starts to rev up. It especially revs up when I put it in park to turn it off. Sometimes it will act like it's giving itself gas while I'm driving down the road and I can take my foot off the gas pedal, it will seriously go up to 55 mph. Also, sometimes when this problem happens my front driver side wheel and rear passenger side wheel will just spin like I'm stuck when I have my foot on the brake.

When I go to have the codes read, I keep getting the same codes of the sensors I've already had replaced. My friend told me to try changing the ECU but I'm not sure if that would really help. My fluids and pressures are great. I don't understand what else I really need to do. ANY help would be greatly appreciated!!!!!!!

Samantha Jo~

Instead of replacing the sensors when they give you a reading you should find out what the codes actually are. Cross refrence them in your Chiltons or Haynes book and find out what causes the sensors to give you a reading. You do have the book on your truck, right? Hope this helps! :)

Just an update on that lovely Jimmy, it caught on fire back in July. Apparently there is a safety bulletin posted about them. The wiring harness clip will melt on the exhaust manifold and cause it to catch on fire. But, thanks for trying to help! I appreciate it! :)

Samantha Jo~