i have a 90 turbo rx7 with intake and rb turbo back with stock engine/turbo and a 20b fuel pump with larger secondaries either 720 or 680 cc and a afc.. now my question, is the 20b pump on a stock engine,causing the exhaust to blow out heavy raw gas fumes and smoke? because thats whats happening. coolant is not bubbling,smokes not blue, it doesnt smell sweet just raw gas fumes with smoke like grey and some carbon on the tip of the exhaust and how do i fix it if this is the case?



thanks

you might be too rich. what are your afc settings?



mike

it only happens at idle,so the secondaries dont kick in,but to be honest my afc is not set properly..i realized that after. i got the new fuel pump installed when i got my new engine,so the engine only has 20,000km along with the 20b pump and it never happened at first, started to happen afteri mis downshifted,i was at 5000rpm in 3rd gear and misshifted to 2nd instead of 4th so that may of caused it..lemme know what u think.

interesting. but i dont think the mis shift will cause that. cats on or off?

no cats, have a rb turbo back exhaust.,can anyone verify that if that the 20b pump is giving off to much pressure this can happen?cars coming out in a month its in storage right now..so i'll start troubleshooting the issue,another reason why im going stand alone. what other things should i look at? could it be that the omp is shot and theres condensation going on by any chance? i just dont know what to think,i'll check the fuel press once the cars out at idle.

yeah check the fuel pressure, that will tell you if its the pump



mike

k,i'll bring the post back up when i get some results back.



Thanks