Power loss/sputtering with gas petal depression

chevrolet
1500

#1

When depressing the gas petal to get more power for acceleration, or maintaining speed up mild inclines, my truck begins to buck and choke, and looses power. I first experienced this problem a few months back. At first it only noticeable at high speed on steep hills. Over time I either got used to the problem, or it went away. Recently it has returned with vengeance, so that I can notice it at any speed and in any gear, and can make use of only a very limited range in the gas petal before the engine starts to sputter. It starts and idles fine. The air and fuel filters have been changed, as well as spark plugs/wires/rotor + distributor cap, with no impact on the problem. Any suggestions?


#2

So. . what do you drive. I know it’s a Chev 1500 pre-2000, but that encompasses 43 years worth of trucks.


#3

Sorry about that. It’s a 1992 Chevy C1500, 4.3-L two wheel drive


#4

OK. The first thing I’d do is have a look at your fuel injectors. If one is clogged or sticking or for some other reason not dispensing enough fuel, then you could get symptoms like you’ve described.


#5

I would check for exhaust system restrictions. A vacuum gauge can do this for you quickly and easily. And get a fuel pressure gauge on it.

Is there a check engine light on?


#6

The check engine light seems to work in that it comes on along with the other dashboard lights when turning on the vehicle, but otherwise does not come on while the vehicle is running.

This may not shed any light on the problem at all, but when the truck is in park or neutral I can rev the engine normally and achieve high rpm without any indication of a problem. The sputtering only happens when in gear.


#7

Weak fuel pressure would seem the most likely cause.


#8

Make mine another vote to start by checking the fuel line pressure. These symptoms are typical of fuel starvation from a failing pump, and the age of the vehicle is right for that type of failure.


#9

Thank you all for the help!