I have a '95 pontiac grand AM with about 208,000 miles on it. About a week ago, i noticed it was getting harder to start when the engine is cold. When the engine has warmed up, it starts up right away, however, the engine begins to sputter and sounds as if it is going to die. The engine still sputters while driving and the car begins to jolt back and forth. When I come to a stop, the car sounds as if its going to shut off. Today, I started the car and it was sputtering so I turned it off and then wasn’t able to start it for about 40 mins. I let the car sit for about 20 mins and then tried it, started right up. What could be causing the sputtering and engine throbbing? What’s wrong?
How old are the spark plugs and the spark plug wires?
Just replaced both two months ago
Did you check for a leaking fuel pressure regulator?
No, but how would I do that?
Look along the fuel rail and you’ll see a metal canister with a single vacuum hose attached. Remove the vacuum hose from the regulator, and if gas leaks out of this vacuum hose connection, the fuel pressure regulator is leaking and requires replacement.
A failing fuel pump is also a strong suspect. I used to have one of these cars. Mine exhibited these exact symptoms as the fuel pump was breathing its last, so to speak. Check your fuel pressure when the car is doing this to verify a problem with the fuel pump.