Sometimes the car boosts sometimes it doesn't at WOT.

I have to let off the gas and get back on the gas then it usually boosts.

I heard that this is somewhat common on the PFC as a bug.

Someone told me that disconnecting the idler control valve will fix it.

any other ideas?

 

Single or sequential twin? suspect the latter. Sounds like solenoid or actuator or harness issues.

 

seq.

 

i don't think it is a problem with the pfc. as twokrx7 said, it sounds like a solenoid or wiring harness issue. could also be vacuum but since it's only sometimes i would say wiring harness. you probly have a loose connection or damaged wire.

 

it's intermittent.

also the wiring harness has been replaced.

 

sorry, i don't know then. i would personally check all the connestions and check the sensors and switches on the commander. other than that i have no idea.

 

Remember that the FD has both vacuum and pressure tanks and it takes both systems working correctly to operate sequential.

 

Is it when you get on it semi-hard (enough to kick in the 2nd turbo) take it past transition, leave it in gear coasting down, then floor it again and no boost?

Tim

 

TIM:

yep. that's pretty much what it is.

i heard that it's a PFC thing.

 

I have kind of the same problem. Before the PFC I had 12-10-12 with a little creep in third gear at times. Now I get like 8-6-15, with no other changes other than the ECU. Granted my gauge may be a bit off but ever since I installed the PFC, I'm not getting a lot of boost on the primary. If I get out of the gas and back in it shoots to about 10 or 12. I don't have the commander and may just need to buy it but I did tell RX7store what mods were on it so he tuned it accordingly. Any other ideas? what about a boost controler?

 

I think it ties in with what Chuck said. My old stock ecu with the PFS PMC did the same thing, the M2 stage 3 did it, the PFC does it. Basically from what Brian at M2 thought, the car goes into vacuum when you let off and coast down (after transition), the car's seq. system is basically stuck at the wastegate is left open, hence the extremely slow boost. IF you just push in the clutch and let out in the same gear can you then boost? I'm not sure if I buy the story but that's what Brian thought.
What other ecu's have you had and have they done it as well?

Tim

 

any idea about the strange boost pattern? Even if if lay into it from a stand still, I'm getting low boost before transition. What can I check? Does it just need to be tuned better?

 

The only ecu that doesn't do that is the stock ecu.

Man, the FD is soooooo cursed with bugs.