20 Most Recent 1991 GMC Sonoma - Page 7 Questions & Answers

on first gear it shifts rough it likes gives u a jump and after that it shifts good couldit be the pumpkin

No i think the box needs taking out and stripping and reconditioning ,these older vehicles are not computer controled but mechanical controlled ,so check the vacumn pipe from gearbox to the inlet manifold for deteroration

The converter is located in the exhaust system, it is a part of the exhuast system and to replace sometimes a torch may be needed to sperate from exhaust, heres a diagram to help you locate it. the first thing is to cut or remove the clamps on the front and rear of the converter, next is to remove it, this is where heat may be needed to loosen the ends to be able to slide old one out, once the old is off its easy to install the new one it slides on and its held on with new clamps, hope this helps.

The radiator or a hose is blocked or the water pump is defective or the thermostat is stuck closed.

Got kind of confused because I'm pretty sure the Sonoma didn't come out until 1992 but then again I could be wrong. Not perfect you know. Anyhow this is the firing order for the GMC 2.8 Liter engines from 90 - 93 (see picture below). I hope this is what your looking for and I hope it helps. good luck.

did you check your starter? solenoid fuse relay? if the engine dont turn over first start with starter thast the one responsible for the crank shaft to turn.

bleeder valve on slave cylinder at transmission

You need to replace the heater core as it is leaking coolant.

First make sure your coil is good also your ignition module your crank sensor will also cause a no spark situation start with these let me know something.

chances are the e brake cable is sticking just enough to leave the light on check the back breaks to see if there dragging and i would check the switch also.

Hi and welcome to FixYa!

Don't you worry. White smoke during cold start ups is just normal. The tail pipe will usually have moist around it so don't panic. You still have a good engine so don't be bothered.

Hope this helps and thank you for using FixYa!

I am not posative but you might try looking behind the side kick pannels if its not behind the glove compartment where they are usually located. . Hope this is helpful

Have you checked the injectors and wiring. sounds like bad injector or wiring not sending pulse from pc.

that will mess with the system as for it fixing ur problem. im not sure what may have gotton fried.temp. sensor tortole position sensor.....ect........hope this helps

It sounds like the coolant is not circulating through the heater radiator. You may have a blocked heater hose but I suspect that the control wire/cable that goes from the heater control lever has broken or become disconnected from the heater tap that controls the volume of hot water through the heater radiator. Some times there is also a flap in the air ducts that is operated by the heater lever that varies the amount of air that is heated. The tap is usually in the engine bay or may be tucked in behind the air ducting. On some models the controls are operated by very small vacuum lines and the rubber hoses can become hard and not seal fully on the the pipes. If this is the case, check the places where the hoses connect to the control or the actuators.

ECMB fuse it is hot at all times and sends power to the ECM ( computer cavities c15 and b1), oil pressure switch (to power the fuel pump when there is pressure) and the fuel pump relay. All orange wires.
So while checking those items also check the fuel pump and all their circuits.
I think the last person that had this problem had replaced the fuel pump and that fixed it.
I got this info from a chevy truck owners forum and also researched other other sites, the most common thing to blow the ECMB fuse is a shorted fuel pump or fuel pump circuit wiring, disconnect the fuel pump at the tank, if the shorts stops and fuse dopesn't blow replace the in tank electric fuel pump.

OK, take the 1991 GMC Sonoma to Sears, Walmart, or your local battery retailer like Autozone or Advance Auto Parts, and have them test the starting/charging system. In many cases they'll do it for free or charge a nominal fee.

Also, you may in the interim check the connections to the battery to make sure they are shiny and clean when removed. Use a wire brush, if necessary to clean them up.

No cable. It has a vehicle speed sensor. Sounds like it is bad. Check for power at the horn with a test light when someone presses the horn pad. The horn might just be bad.

TRY THE BREAK SWITCH LOCATED ON BREAK PEDEL