Hey there, Ended up only being able to find a S4 engine for my S5 RX-7 and decided to just go ahead and put it in. Everything went well, although I did have to make a couple of modifications to the EGR system, as it does change between those 2 series. So, I go to start this puppy up and it starts up easily enough, but this sucker won't idle to save its life! I checked timing, it was off, so I adjusted it and still no go. I checked injectors, I checked wires, I checked plugs. I'm reaching a point where I'm really at a loss as to what this problem could be.

So...for the pros out there, here are the symptoms.

Vehicle will start easily, I hear strong bumps from the rotors. when she starts she revs up to past 3000 Rpm and holds there for a second, before dropping down, trying to idle, and dying.
The engine will rev freely, there is no hesitation there. Upon a test drive I encountered absolutely NO power past 3500RPM, it trys to cut out and sputters until I take it out of gear while moving.

So, thats the current dilemma. Any help would be awesome!!!!

 

IS this NA? I know you checked, but the bumping...Make sure you have the spark plugs arrange proper, Leading on the lower position and Trailings on the top. Rotor 1 is to the front of the car, so L1 is The front lower plug. The EGR should be removed entirely and given a block off plate.

I just did this same thing and had not ground the lump right by the clutch inspection window and had a huge vacuum leak at the LIM and UIM junction.
Also, you do need to keep the OMP plugged in or the ECU goes into limp mode. A vac leak is a likely culprit though.

Let me know what you find.

 

i'm thnkin the omp too.

 

Good stuff.

 

<edited for flaming>

Anyhow, I agree with the vacuum leak idea. Also, mine ran like that when I forgot to plug in one of the wire harnesses to one of the coils. So check and double check all your connections. Then spray around with some carb cleaner to check for vac leaks.

 

Hey all, thanks for the suggestions. It ended up being a leak between the LIM and the UIM. Also, I had installed the wrong crank pulley so my timing was well over 90 degrees out. Thanks so much for the suggestions fellas.