1999 4.3 misfiring
I'm running out of ideas on a problem with my 99 S10 4.3
The truck will start and idle fine however as soon as you feed a little gas it starts to miss.
Giving it even more gas is either covering up the misfire or it is clearing and seeems to run better.
I've just replaced cap/rotor wires and plugs.
The problem seems to get worse whenever it gets even slightly wet/humid.
I had Cragen hookup a analyzer and it gave a "random misfire" error code.
Does anyone have an idea of where to look?
I would look at replacing your coil, moisture will commonly mess them up if they have a crack in them. If the coil is going out, the more you require from it, the more the engine will miss. It would create the code given. That would be my best educated guess from the information you gave.
Just as a possibility I may also suggest trying a MAF cleanner, it should be about $8 a can. If it improve significantly, then I recommend replacing the MAF. Even though the frequency could be operating within specification, if it does not change as quickly as load on the engine changes, the engine may not be able to fire at the right time.
your problem is a bad throttle position sensor, i had the exact sme problem, changed everything out but that sensor and it finally stopped doin that once i replaced the TPS. same exact conditions, whebn it got humid or after a rain it ran like shit lol
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