Top 20 1993 GMC Sierra K1500 Questions & Answers

Does it miss at idle or going down the road, maybe both? Any applicable trouble codes? If you have that spider fuel system, I usually suspect that first. That system is noted for problems. You could try a cylinder balance test, engine idling, you could kill the cylinders one at a time, quickly. If you kill a cylinder that has no effect on the idle, the cylinder is dead. Then you have to decide if problem is spark--fuel--compression on that cylinder.

I'm assuming "white" smoke and not "black" since you didn't mention. If white smoke, it's coolant or oil leaking into the cylinder heads while it is not running. If oil and from leaking valve guide seals, it's not a serious thing and basically a nuisance. Just keep your motor oil level topped off until you have new seals installed or dispose of vehicle. If coolant, it's a much more serious problem. The liquid in the head will do two things. One, foul the spark plug and possibly cause hydraulic lock (fluids cannot be compressed and cylinder locks up) Check you oil level and if keeps going down a quart every few hundred miles, it's the valve seals. Check your coolant. If down, it's possibly a head gasket leak, which is not uncommon for vintage and make. If coolant keeps going down and not leaking on ground, that's a smoking gun, not to make a bad pun, for a leaking head gasket. At this point, it's prudent to first invest $10 on Barr's Leak Copper (looks like liquid copper in a jar) and add to your coolant system. Follow manufacturer's instructions and then see if problem either persists or abates. If it abates, go and buy a lottery ticket since you're very lucky and solved a serious problem with an inexpensive fix. Good Luck

Check at injector wire with a test anoid light blinking while cranking engine if there is a signal to the injectors. The + signal is from a FUSE. and the - signal is from the ECM. If it's an ECM problem, before changing it. Check all positive and ground at ECM pinout check. Hope it helps.

The fuel level gage sending unit is defective, very common problem. The sending unit comes with a new fuel pump and is referred to as a module, also make darn sure you replace the fuel pump connector at the fuel tank, solder and shrink tube the new connector on, DO NOT USE CRIMP CONNECTORS.

it indicates injector problems leaking injector seal /s dirty injectors you can try moving no 4 injector to another cylinder and if the misfire moves as well , replace that injector it it doesn't move the misfire , it is coils or ECM problems

That is not a radio. That is a control head. The 7 wires carry data to the radio brain which on this trucks is a silver box located directly above the gas pedal. These trucks also had an optional cassette player/ cassette and eq unit that was mounted in the center of the dash that also connected to the radio brain as well.

I'm going way back into my alcohol erased memory on this one, but check your oil level sender. I ran into this problem many years ago and it seems like that was the culprit.

Sounds as if the clutch is no good or is engaged constantly. Possible clutch worn out or throwout bearing is seized on input shaft

I would say that you have a fuel delivery issue, or contaminated fuel! Change the fuel filter, check for proper pressure at the fuel rail, replace the pressure regulator and/or pump as necessary, and verify that debris is not clogging the fuel intake strainer. If fuel system is operating properly, suspect contaminated fuel (especially if you have been using ethanol blend fuel). Change all fuel in vehicle, and likely your issue will be solved.

what is it you want to know ?

I'm pretty sure its on the circuit with the courtesy lamp fuse. That fuse is in the fuse box near the brake pedal.

Check your fuses, if good then you have a broken wire in the harness.

They don't adjust. They go in the tbi and seat to the bottom if they are leaking you need to change the o rings on them.

Could be ten things What has been tested so far & the results?

Check for spark at the coil while cranking ,also fuel

Question, does this pickup blow black smoke on idle or at a stop sign. If so check your map sensor might be plugged up or unplugged or bad.

first check bulbs under the bumper twist and pull out the wires leading to the light if bulb is kinda silver and black inside the bulb is blown if the parking lights work its most likly the bulb

Here are directions....

1. Park the vehicle on a level surface, with the fuel tank about 1 / 2 full and with the vehicle empty of all extra cargo (unless normally carried). The vehicle should be facing a wall which is no less than 6 feet (1.8m) high and 12 feet (3.7m) wide. The front of the vehicle should be about 25 feet from the wall.

Fig. Fig. 5: Location of the aiming screws on most vehicles with sealed beam headlights

Fig. Fig. 6: Dual headlight adjustment screw locations-one side shown here (other side should be mirror image)

Fig. Fig. 7: Example of headlight adjustment screw location for composite headlamps

1. If aiming is to be performed outdoors, it is advisable to wait until dusk in order to properly see the headlight beams on the wall. If done in a garage, darken the area around the wall as much as possible by closing shades or hanging cloth over the windows.
2. Turn the headlights ON and mark the wall at the center of each light's low beam, then switch on the brights and mark the center of each light's high beam. A short length of masking tape which is visible from the front of the vehicle may be used. Although marking all four positions is advisable, marking one position from each light should be sufficient.

Fig. Fig. 8: Low-beam headlight pattern alignment

Fig. Fig. 9: High-beam headlight pattern alignment

1. If neither beam on one side is working, and if another like-sized vehicle is available, park the second one in the exact spot where the vehicle was and mark the beams using the same-side light. Then switch the vehicles so the one to be aimed is back in the original spot. It must be parked no closer to or farther away from the wall than the second vehicle.
2. Perform any necessary repairs, but make sure the vehicle is not moved, or is returned to the exact spot from which the lights were marked. Turn the headlights ON and adjust the beams to match the marks on the wall.
3. Have the headlight adjustment checked as soon as possible by a reputable repair shop.

Inside Fuse Panel....

more info required