420A my 420a bogs down under heavy load then stops when i let off the gas any ideas?

[SkillerJoshua]

I have a 99 gs eclipse with 420a and it keeps fouling all 4 plugs and then it spits while idling. it also bogs down when im hard on the gas then runs normal when I let off the gas. I put in new plugs many times but its just a temporary fix. it has new wires coil pack and egr vavle as well. I don't know what else it could be. any ideas???

 

[sirbow2]

wording is a bit weird, but i think you're trying to say the spark plugs keep getting gunked up. i'd try checking your fuel injectors as they might be getting stuck open, or, something is causing them to inject too much fuel.

 

[Terrancep7]

Are you getting any check engine codes

 

[fisher83]

Take a look at the camshaft position sensor. My end cap for the exhaust cam was leaking oil by and getting between the sensor and trigger. ..would make my car studder and idle rough...could be making the ecu lose track of the cam in relationship to the crank and mess up your timing and fuel injectors.....

 

[DSM1G90]

What gap are the plugs, for it could be that the gap is too close and you're snuffing out the spark when adding power.

 

[Mitsumungst-gvr4-tsi]

Sounds like a fuel issue, possible fuel pressure regulator being over ran, or just bad. Or maybe the vac line is off or ripped for the fpr. Possible a leaking/clogged injector or bad o2 sensor throwing off the mix. Maybe your timing is off a tooth. I would check base fuel pressure and base timing and go from there!