Ok- My mods are in my sig. I recently started the Home Depot Hyper ground install, and i got 2 grounds done, the negative battery terminal, and the short ground attatched the the UIM behind the engine. It completely eliminated my 3k rpm stumble! Woo hoo, that was easy! It also fixed the strange bucking problem i had at light throttle, the car would hesitate BADLY (aka, bucking back and forth several times), at any rpm, when accelerating at vacuum. So my car's running great, except needing a new 02 sensor. (Which i have, is going to be installed soon) So I'm driving to work several days later, slowly accelerate to 4k, and wham, its like hitting a wall. all my power dies (not electrical). WTF! I try it again, same thing. Can't get the engine over 4k. I park for the day, and drive home at night, and its fine! no problem at all. argh. Anyways, the same thing happened a couple days later, then stopped. Any thoughts on this? (yes i've searched a lot) The only things that i know of that switch on are the secondary injectors (could be clogged?), and the secondary turbo starts to spool. (turbo going bad?). So i'l check my turbo on my own, how do i know if its the injector? or is it something else? Help please!

 

What do you mean by "can't get the engine over 4K"? When you say you're "hitting a wall", yet also claim that it's not electrical, your description sounds a bit confusing. To me at this point, it sounds electrical.

 

Sounds electrical to me too. Does not sound like a turbo problem, especialy since it ran good at night after the first problem. I would go thru and check all the connections in the area where you were working. Something was probably knocked off while you were putting in the ground wires.

If you don't find the solution, try it again at night, and let us know.

 

disconnect the negative battery cable for a few minutes and reconnect it. I had the same problem and that fixed it.
-stephen

 

i reset the ecu when i replaced the grounds. remember it has only done this twice, so it happens intermittantly. i didn't do anything to fix it, nextt im i started my car it worked fine. so my car is running fine now. let me see if i can describe it better. ok, i'm driving in first, and at like half throttle, and at 4k, the car stops accelerating. it won't rev above 4. its a very abrupt loss of power (i don't mean a loss of electrical power, all the lights and everything work fine), its so abrupt that it jerks me forward. imagine the 3k hesitation, and make it 10X worse. thats why i thought it might be the injector, it kinda feels like the engine isn't getting any fuel/spark. (although i've never hit fuel cut, so i don't know what it feels like).
NEW INFO- Seems like its connected to one of the boost settings on my pms, both times it happened i was on the same setting. I switched it back, and the next time the car ran fine. Just realized this, i'll test this on the way to work today.

 

Fuel cut. It seems the PFS PMS is very sensitive to knock. Most people end up relocating their knock sensor (most likely to the rear rotor).

 

REALLY? It was cutting fuel at HALF THROTTLE????? i don't think i was even boosting positive pressure.

 

From what I've read, it has to do with the PMS reading the knock reading (which is why relocating the knock sensor fixes it).

https://www.rx7club.com/showthread.p...threadid=49438

https://www.rx7club.com/showthread.p...hreadid=215380

 

if thats true, then if i richen that map up, it should make it go away, right?

 

Not necessarily. The problem is the PMS is overly sensitive to the knock readings on some cars. If your car is one of these, ultimately, the fix is the relocate the knock sensor.