it just slows down like there is not enough fuel when i have a half tank and my idiot cluster shows the engine light then i turn the engine off and back on it works fine..... the car drives fine in low rpms but as soon as i get on it it cuts out usually at 6500 and i feel a large lack of power
anyone had this happen before???

 

is your fuel pressure good?

 

same problem i'm trying to diagnose, the secondary injectors aren't kicking on at all as if the ECU isn't seeing a load on the engine. the primaries just can't flow enough fuel so it starts to preignite at around 6300 RPMs

never really seen an issue the same as this before.

 

yes i have fuel pressure

and i feel the power from my secondary's come on (thats at 3500right???????)
but then it just quits or fails rather

 

If you have a check engine light-pull the codes and find out what is going on.

 

Injector crossover is 3800 rpms iirc.

 

You shouldn't 'feel' the injectors, it's probably your aux ports/vdi that you feel. Typically hitting a wall at a high RPM is lack of fuel/ignition break-up. Check your plug wires/plugs, and as Karack said, your secondaries.

 

I actually just posted something along these lines last night.
My 90 n/a gxl is doing the exact same thing.
No idea why either, it is running fine/great until I hit 6-6.5k and then it is just like it has no power but it sustains the 6-6.5k rev.
I'm checking my plugs once I get back from work.

 

the primaries can only sustain the mixture to about 6300 RPMs, after which it will be in the 15+AFR range and begin to misfire.

 

for the info after the rain lets up ill be checking everything

 

Check your Rear Rotor housing ground. 99% positive thats probably the problem. Same thing happened to my 88' GTU. It was like hitting a wall @ 6000RPM. Clean it up and inspect it.

 

+1

Thats what I'm going with also, I have to wait till this weekend to fix mine, but I had to move it because I f'd up when I was re-grounding it.
That is probably why it is acting like it is.

 

if it stops hard it's your secs no coming on line. if it falls on its face then VDI or limp mode.

 

Did you guys ever figure this out? My s5 has been living with this cancerous problem for years. What started out as "it's probably something in the harness" has become a long exercise in frustration fueled by obstinateness.

So far, three shops have given up with "WTF" as the diagnosis.

The grounds have been checked (several times). The ECU has an RTek 2.0 for data logging purposes. Last time I spoke to Ben, the only (?) unusual finding was a very noisy signal from the atmospheric pressure sensor.

Here is the full story:
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/power-drop-noticeable-hesitation-issue-high-6300-rpm-802779/

 

It sounds like the VDI valve isn't opening.

 

This happens at 5500 rpm. The power loss in my car starts at 6300 rpm, very precisely and reproducibly.

Besides, the 6PI and VDI actuators and entire solenoid/emissions rack have been deleted from my car, so there would not be a sudden power decrease due to malfunctioning of either of these systems (it could, however, lead to an overall drop in power throughout the rpm range).

I resurrected this thread primarily to redirect readers to my 6300 rpm power loss thread, which finally has a resolution:
https://www.rx7club.com/showthread.php?t=802779

 

I'm hoping this problem got taken care of. 89 NA GXL, but I have huge ported S4 irons, S6 rotors and housings. I'm in the process of searching, so my apologies for the thread revival [and any inadvertent thread jacking].
I don't have 5/6 port actuators any longer as a part of my port job. As for VDI, I'm not sure how to check it. I know I need to do some grounding as I get some dimming when I press brakes with lights on, my interior map lights don't work and whatnot. Also,I get the narrowband TPS code if I'm not on the gas, but touch that pedal at all and the code goes away. Idle is a steady 950 but sometimes bumps to like 1100-1200 and drops back down after a little bit.
The turbo guys and the FD guys talk about fuel cut from what I have found and most have solved the problem with refreshed injectors and a bigger pump. But with my TPS light and my [most likely] bad grounds, would that be a better place to start?