2001 GMC Jimmy continuing problems.

[skywalker45]

Well I replaced the fuel pump and that fixed the problem

Now something else has come up. The service engine light comes on and stays on and the temp gage is no longer working. I don't know what happened. Any suggestions? Is the gage driven directly by the temp sensor? Where is the temp sensor located on this model year vortec 4.3L?

On another subject -- I changed all the plugs except the crappy number 3 with the steering shaft blocking it. I tried to follow the tutorial here for taking the shaft loose and moving it out of the way except my shaft appears to not have the 11mm bolt that you need to remove. Is there any other way or is mine different? I don't see a bolt in there anywhere. Thanks.

[Chris Stewart]

Yep, yours and my daughter's S10 is different. When time to do hers, it looks like the drivers side motor mount will get unbolted, that side of the motor gets raised 1 inch, the driver's side front tire removed and I'll access the #3
sparkplug through the inner fender after moving the rubber flap out of the way...unless somebody else has an easier way to pull this off.

[skywalker45]

Great! I'll look forward to maybe having to do that then as well. You wouldn't happen to know where the temp sensor is located? I've looked all over this engine and can't find it. Also is the temp sensor what actually drives the temp gage? I know that sometimes it's a different sensor. My father-in-laws sunbird has two of them. One is a coolant temp sensor and the other is an engine temp sensor and it's the engine temp sensor that drives the temp gage. I'm not sure about my Jimmy though.

On the spark plug note. I once had a '95 S10 that I was able to reach the number 3 plug with a wrench of some kind but I can't for the life of me remember how I did it. There has to be several ways of doing it. Someone suggested grinding a few millimeters off of a spark plug socket. This would give you enough room to get a ratchet or universal wrench in there, maybe. I haven't tried it so I can't speak from experience.

[2001jettavr6]

You need a special tool for that spark plug, my wife's father has the 4.3 vortec and were not able to get that one out. Upon research he had to get some special tool to get that one. I think they had it at auto zone but definately at the dealership.

[Chris Stewart]

Originally Posted by 2001jettavr6

You need a special tool for that spark plug, my wife's father has the 4.3 vortec and were not able to get that one out. Upon research he had to get some special tool to get that one. I think they had it at auto zone but definately at the dealership.

On a '97, the coolant temperature sensor at the base of the thermostat housing provides info to the computer which disburses (cool huh? )a signal to the temp. gauge as well as uses the info to set fuel & ignition timing.
A trick wrench would be great for retrieving #3 spark plug.

[skywalker45]

OK. On my Jimmy the coolant temp sensor is on the driver side of the block mounted just above number 1 plug. Turns out that when I was working on the fuel spider I must have yanked on the harness too hard and broke the plug on the sensor. I fixed it today and temp gage works and service engine light is out. I can only assume it was on because the ECM was receiving no input from the sensor. Now onto that number 3 plug --

I managed to change it today. Turns out I did have a bolt holding my steering shaft onto the knuckle but it was located in a slightly different configuration than the tutorial on this site. You might want to check your daughter's truck again just to make sure. It took me quite some time to find the bolt and even longer to pry the coupling off the knuckle and even LONGER to get the shaft back on but it did collapse on itself quite well and I was able to move it out of the way to get to the number 3 plug through the driver side fender well. I believe this is the easiest way to do it unless you can get your hands on one of those fancy tools. I have heard they make them. It's some kind of universal wrench. Good Luck!