Howdy all- new here, been lurking for a while and finally took the plunge and bought my new/used Jimmy.

Well, I got it home, and now I'm finding an issue. I live at the base of a steep driveway. When cold, the truck doesn't want to back up the driveway. The trans will engage in R, the engine will run, but it will not move, the engine willnot rev up, but just lug and lope at 1000RPM. I drove it 160 miles home over hilly interstate with no issues, and getting 21mph with the AC on, aside from maybe a rough idle.

Right now, I'm either thinking a transmission/torque converter clutch issue, or an ignition problem. First plan tomorrow is to do a full tune up, cap, rotor, plugs and wires. After reading a few things here, maybe checking the EGR valve as well.

Any kind of drive train issues that these are known to have? And what's the normal output of the electrical system? I've noticed that this only happens from idle, when the alternator is only putting out ~12v...

So far, only one check engine light, that went out on its own, it came on right after refueling, so i'm guessing it was a loose gas cap.

Thanks,
Retired Freigth Dawg

 

Along with the full tune up I would also replace the air filter. After I bought my 2000 Blazer I noticed some hesitation only when starting to move, replaced the air filter and it works perfectly now. Getting ready to replace cap, rotor, wires and plugs in about 800 miles.

 

I would check alternator my 2000 puts out 13.8v-14.1v at idle to 3000rpm and more...the internalvoltage regulator in the alternator might be shot. When A/C is on then more like 13.8v. but if you are showing 12v on the Instrument Panel gauge then that might be your problem, the fuel pump needs more than "12v" to function at top efficeincy...

 

Thanks for all the tips, tune up is today, got the whole weekend off to mess around. Interesting change today; it was about 15 degrees cooler out today, and I had no difficulty backing up the driveway at all. And the alternator was indicating normal on the gauge and after put my multimeter right on it. Of course, my old car would do the same thing; once the temps got above ~30C the volts would start to drop at idle.

Looks like this might even be more fun changing these plugs than it was on my old 3800 powered Buick! Though, here's hoping it proves as reliable. At the old job, we had a salesman who had an 01. Last I heard it was up to 275k on the clock, off road on jobsites damn near everday. We did have to put a Jasper engine in it after 160k. Of course, that was 15k after our fuel farm was filled backwards (diesel in the gas and gas in the diesel) and he took a whole tank of ~70/30 diesel/gas mix. And drove 80 miles on it!