OK... I just finished installing a used engine into my 1993 rx7. The harness was cut at the firewall, so I soldered on the connectors for the ecu. I checked over all of the wires that I could with the factory service manual and traced them to where they go. I got the car started and it idles fine and drives around, but if I hit any boost, it cuts out real bad. It won't let me boost at all. The previous owner converted this from an auto to a 5 speed and a couple of the wires arn't going to anywhere. If I remember correctly it is the 1st gear, 2nd gear, neutral switch, and some more that I can't remember. The car also has a J&S knock safegaurd, so I bypassed it to see if it was causing the cut out, but it wasn't. Does anybody have any ideas to why it is cutting out?
Thanks for any help in advance,
Jesse

 

Could be a lot of things....TPS needs adjusted, the ecu is in "limp home" mode from a bad code (definitely check this), there is a problem with the secondary injectors and/or fuel pump, etc.

I hope you properly soldered the harness and wrapped it all back up...a new harness isn't that expensive and is the route I would have gone there....

 

I dont think that the tps is the problem, because I can rev it without the studder as long as I don't build boost. I am throwing a check engine light however. I double checked all the connections to the pressure sensor and tps, without any luck. If something is switched up on the solenoid rack, would this cause a problem like this? I noticed that the accelerated warm up system isn't hooked up at all, but that shouldn't cause this, right?

 

i agree i think its in limp mode. my friend car did this a few nights ago. we unpluged the batery and pluged it back in and it worked after that.

 

ok... damn pressure sensor ground was bad. I fixed that, now I can boost, but when the secondary turbo trys to kick in, it dies out completly like I'm hitting a rev limiter. Could this be a bad solenoid, like the wastegate control or turbo precontrol?

 

I'm having the same problems with my secondary turbo...
In 1st gear it won't activate, and it's like hitting the rev limiter.
In 2nd gear it works fine
In 3rd gear it activates one second after the engine studders.
I got the car yesterday, and I haven't tried the limiter in 4th yet

 

I am starting to think that something is up with my secondary fuel injectors. I am going to test them out today and see if they are getting pulsed or not.

 

I bypassed the turbo precontrol and wastegate control solenoids and it feels pretty good now. No more "rev limiter", haha. Although its running really low boost because of bypassing them. On another note... I left the car idle for like 10 mins after test driving it, and when I got back in, I touched the gas pedal and it tried to die out, so I parked it and called it a night, haha. Its just one thing after another!

 

https://www.rx7club.com/showthread.p...ntrol+solenoid

If your charge control solenoid is not working, it'll put the car into limp mode. You can rev up fine without building boost, however if you try and boost it'll limit it.

What is the engine code that your throwing?

 

did you make sure your leading coils are working. I had that problem, any time I would hit 0hg, it studdered.

 

Its working good now with the 2 solenoids bypassed, even though it is trying to build to much boost. I saw it go past 10psi on about 3/4 throttle, so I let off really quick, lol. I ordered a whole new (used) wiring harness and solenoids to get it running right. My rad had a small hole in it, so the car was trying to over heat. I'm glad I caught that in time! I took the rad to a shop to have it repaired. Thanks for all your help!