fuel pump

I have a 1990 chevy c1500 with a 5.7 lt. It started running like crap and the service engine light came on. The codes were lean exhaust, egr valve and o2 sensor. I have replaced egr valve and solenoid, o2 sensor and map sensor. None of which made a difference. Now my fuel pump is out. Could that have been the problem the hole time? It was missing when it accelarated but ran smooth when at a steady speed and idled up and down

yep. sounds like fuel starved symptoms. check fuel pressure cranking if it doesn't start...sorry don't have spec's for you...will try to get some tomorrow.

I have a 1990 chevy c1500 with a 5.7 lt. It started running like crap and the service engine light came on. The codes were lean exhaust, egr valve and o2 sensor. I have replaced egr valve and solenoid, o2 sensor and map sensor. None of which made a difference. Now my fuel pump is out. Could that have been the problem the hole time? It was missing when it accelarated but ran smooth when at a steady speed and idled up and down

Like they say codes do not say replace parts but check it out first.

Low fuel pressure almost always throw a lean exhaust code.
What was the code no?

I had similar problem on my 98 Silverado. It would sputter and die, but only under a load - such as climbing a long hill. Otherwise, it ran great. The truck gave out all kinds of different codes, and the dealership was originally stumped. They replaced cap and rotor, then I did wires, fuel filter, etc, etc.

My problem turned out to be the fuel pump. I had the pump replaced by a local shop. But they used a local brand, not OEM. That pump lasted about 2 months, then same sputtering started again. This time, I had the shop use OEM fuel pump and now all is well.

So, I would suggest that you be sure you have a OEM pump in there.

Good luck.

I have 98 K1500 that showed the same problems during acceleration. I found the problem to be a plugged fuel filter, which was starving the engine at the higher flow rates. My pump never quite but it did make a loud whining noise until I replaced the filter.

I have a friend with a 96 K1500 that has gone through a couple fuel pumps. His factory pump quit after 160K and he replaced it with an aftermarket pump. That one quit after a few thousand miles. He's back to an OEM pump.

I have 98 K1500 that showed the same problems during acceleration. I found the problem to be a plugged fuel filter, which was starving the engine at the higher flow rates. My pump never quite but it did make a loud whining noise until I replaced the filter.

I have a friend with a 96 K1500 that has gone through a couple fuel pumps. His factory pump quit after 160K and he replaced it with an aftermarket pump. That one quit after a few thousand miles. He's back to an OEM pump.

the reason there are many with these fuel pump problems are because GM does not give a replacement interval....most with few problems replace the filter at 30,ooo mi...the next reason is because of constantly running with low fuel ,,at / below 1/4 tank....This damages the pump with overheating ...with low fuel in the tank more crap enters the pump and plugs up filter etc....

with a good fuel pump, a restiction like a filter dirty will make the pump louder ..

whenever the pump is replaced replace the fuel pump relay ..A bad pump can damage the relay contacts !