93 GMC Suburban?

Question

It just started this problem yesterday. If at a stop light, the vehicle sputters almost to the point of stalling. And if letting off the brake a little say to ease up, the vehicle will jerk almost violently. And at take off the vehicle still sputters almost to the point of stalling. What's wrong with it?

The engine also give off a weird odor after being driven. It smelled like a mixture of gasoline and oil.

Answer 1

One of two things that come to mind. I would say either a fuel pump or a vacuum leak. I think the vacuum leak is more likely cause at low RPM the fuel / air mixture is wrong and will threaten to stall the car due to low idle speed. I would listen to the engine for a "sucking" sound by chasing the vacuum hoses.

Good luck!

Answer 2

You will have to start looking to find what is wrong. The biggest problems with these were spark plug wires corroding at either the distributor cap and/or the coil tower. To check you have to remove the air cleaner assembly and gain access at the top area of the motor. One by one, take the spark plug wires off of the dist. cap and the coil and inspect both connections for the presence of a white powder which is corrosion. This causes a major misfire and will have to be replaced, meaning all of the wires, cap, rotor and the coil assembly if it has corrosion on it as the corrosion goes down part where you can see. If there is no problem found, look at all of the plug wires and connectors for any problems with splits in the insulation or carbon tracking, even in the part to the plugs. I would also remove the spark plugs to inspect for carbon tracking, being worn out or fouled as well. If nothing found, I would get looking at the primary parts of the ignition system for a green moldy corrosion which will be evident on the connectors inside the distributor. While you are in there, check the dist. shaft bushings for being worn by trying to wiggle the shaft back and forth. It should be fairly tight but it does have to spin. If this doesn't help, you might be having a fuel pump pressure issue. Good luck.