Hello,
I have a1992 305 TPI z28 auto transmission. The car is hesitating at 50% throttle or less and seems to be at a loss of power and it surges at 60 mph. Has new plugs as well as a new distributor cap and rotor. Changed the ignition module as well. Was running fine, Then check engine light came on,and turned off. Does it Sound like the timing? Any help would be greatly appreciated.
thanks,

Update, i check the DTCand i have code 32 (EGR) and 44 (o2 sensor) on the ECM.

 

If you temporarily disable the EGR, does the hesitation and surging still occur?

 

Let me check and ill let you know.
thanks,

 

Code 44 indicates a possible lean condition (O2 voltage low). Check for vacuum leaks and check fuel pressure. Wouldn't hurt to change the fuel filter.

GD

 

i checked the fuel pressure and i am at 22 lbs, i'm thinking it might be the regulator of fuel filter. the vacuum hose are old but don't appear to be bad. i don't hear them. i will replace them anyway tomorrow. Thanks in advance for any insights.
thanks,

 

Should be 43.5 with vacuum disconnected, and about 35 with it connected at idle. 22 is way low. You need to fix the fuel pressure issue. Pinch off the return line - pressure should go well above 50. If it doesn't then your fuel pump is smoked. Not that unusual.

GD