1997 3500 pickup 5.7

[lahomer]

when the truck is under power it misses and spark knocking. whats the problem? but dose not do it all the time.

[MT-2500]

Originally Posted by lahomer

when the truck is under power it misses and spark knocking. whats the problem? but dose not do it all the time.

Welcome to AF.

To help you with the problem we are goig to need a lot more info.
LIKE
Any check engine or flashing check engine lights or codes?
How are the plugs and wires and dist cap and fuel pressure?

Low fuel pressure and bad plugs and wires are the main cause of engine a miss.
A long with many other things.

How many miles on it and how many miles on plugs and what kind of plugs?
What is fuel pressure readings?

[lahomer]

the engine light is on auto zone said it was the intake air temperture sensor. when i take it to the shop they seem to be lost we put spark plugs and wires last year but didnt change the cap and rotor

[lahomer]

the truck has 130,000 miles on it sometimes it rides good then all of sudden start missing and spark knocking.

[MT-2500]

Originally Posted by lahomer

the truck has 130,000 miles on it sometimes it rides good then all of sudden start missing and spark knocking.

Clear code and retest.
If that code or any other code comes back repair for that code.

Confirm good fuel pressure.

Confirm and make sure you have good ac delco plugs and cap and rotor and check plug wires and good hot blue spark from coil.

Check dist shaft for side play.

If engine is missing you should be getting a code for that cylinder missing.

[j cAT]

Originally Posted by lahomer

the truck has 130,000 miles on it sometimes it rides good then all of sudden start missing and spark knocking.

post all the DTC's that are found . then we can start narrowing down where to do some testing.

air intake temp would be the MAF. I would rather have the actual codes before making recommendations.

130,ooo miles is low . could very well be bad plug wires /plugs.