Rough acceleration

[Sethterry1696]

I have a 93 k2500 with a 5.7 around 60k on the motor has a slight miss at idle wich I think 90% of them do but it runs great up till it shifts into 2nd gear under a hard load then it struggles pretty hard to climb past 2k rpm I'm not expecting much but the fuel economy is terrible has to be around 6mpg

 

[Schurkey]

I have a 93 k2500 with a 5.7 around 60k on the motor has a slight miss at idle wich I think 90% of them do

Nope. Fix the misfire.

but it runs great up till it shifts into 2nd gear under a hard load then it struggles pretty hard to climb past 2k rpm I'm not expecting much but the fuel economy is terrible has to be around 6mpg

Verify fuel pressure. How old is the fuel filter?

Connect a scan tool, verify all sensors and computer outputs.

How old are the usual "tune-up" parts--cap, rotor, plug wires, spark plugs, air filter, PCV valve? EGR works properly? Catalytic converter outlet hotter than the inlet?

 

[Sethterry1696]

Nope. Fix the misfire.


Verify fuel pressure. How old is the fuel filter?

Connect a scan tool, verify all sensors and computer outputs.

How old are the usual "tune-up" parts--cap, rotor, plug wires, spark plugs, air filter, PCV valve? EGR works properly? Catalytic converter outlet hotter than the inlet?

Just put a new filter on yesterday the next thing I want to check is the coolant temp sensor cause my temp gauge seems to read weird there is no cat on it I have a new pump just wanna try the easy stuff before I have to do that

 

[Schurkey]

The temp gauge on the dash doesn't use the same sensor that the computer relies on.

The dash gauge can be way off, and not affect the engine performance.

OTOH, if the thermostat is stuck open, the dash gauge could read way low (too-cool) and since the computer is being told the engine doesn't warm-up, that would screw up fuel economy and power.

If the sensor for the computer were faulty, the engine would run poor, but the dash gauge could read normally.

Thus the suggestion to connect a scan tool and verify all the sensors.

 

[Sethterry1696]

The temp gauge on the dash doesn't use the same sensor that the computer relies on.

The dash gauge can be way off, and not affect the engine performance.

OTOH, if the thermostat is stuck open, the dash gauge could read way low (too-cool) and since the computer is being told the engine doesn't warm-up, that would screw up fuel economy and power.

If the sensor for the computer were faulty, the engine would run poor, but the dash gauge could read normally.

Thus the suggestion to connect a scan tool and verify all the sensors.

There was no codes I checked today

 

[Schurkey]

There was no codes I checked today

Thus the suggestion to connect a scan tool and verify all the sensors.

Verifying that each of the sensors work properly is FAR more important that seeing if any codes have set.

Which is why I'm so opposed to scumbags selling "code readers". They are less than 1/10 as useful as an actual scan tool.

 

[Sethterry1696]

Verifying that each of the sensors work properly is FAR more important that seeing if any codes have set.

Which is why I'm so opposed to scumbags selling "code readers". They are less than 1/10 as useful as an actual scan tool.

I just used a paper clip and jumped the terminals on the obd1 plug I don't have a scan tool for obd1

 

[LC2NLS6]

Fuel pressure, check the fuel pressure. I know, its a giant pita, but it is the only way. And not only that, fuel pressure at idle, but also under load. It's almost easier to just upgrade the fuel pump to a better one than rig the pressure tester up to only then upgrade the fuel pump and clean the ground for it.