chrismore

Here's the specs on the car:

* 1991 RX7 S5
* Full road racer with no emissions and completely stripped down to only what is needed to drive.
* de-power steering
* no emissions equipment
* no omp (bolted to inside fender and wired into ECU to keep limp mode from happening)
* rebuilt injectors by RC Engineering
* ~100 psi compression on both rotors
* RTek ECU is throwing no codes

Here are the symptoms:

I start the car, run great, and I let it warm up. I take it for a test drive down the road (not legally) and I can accelerate fine at the start. Within a minute or so, the car stops being able to accelerate and any throttle application more than say 15% make the engine back fire out the exhaust and the engine dies until I let off the throttle. I pull it back in the driveway and the engine is running rough like it is only running on one rotor. I then cut the power the car and ECU, restart the car, and everything is fine. I am able to rev up the engine, runs smooth, and I am able repeat the procedure above. After a minute of driving, the engine falls flat on its face until I reset the ECU.

I hooked up the Palm to the RTek and I am not throwing any codes. This is almost exactly like the limp mode problem I had when the OMP was not hooked up to the ECU.

What have I tried so far?

* swapped coolant sensor on water neck
* pulled all intakes and inspected wires and tubes
* swapped ECUs

Any ideas? The resetting the ECU fixing it temporarily is very suspicious and it does it on my OEM ECU too. It seems like it is sensor based, but weird that there is no code.

Thanks in advance!

chrismore

The only other thing I have done lately is that I noticed that I never plugged the short metal tube that comes out of the side of the oil filer neck. Is it possible that plugging that line could be throwing this code? Should that tube be vented instead of capped?

misterstyx69

iTrader: (142)

Rtek 2.0?
post in the Rtek section.
Question: does that Ecu have an option to run the omp TOO or take it out of the equation?
if so,check that "box".(thinkin the omp is still in the Loop and it is causing Limp mode.,But if you check it off it may run better..just a guess).
UNPLUG that vent!..it will cause oil pressure build up and it can bypass the control rings.
If you don;t have a catch can on it,just lead that hose to atmosphere.Somewhere so that If oil dibbles out it won't make a mess on the engine.

chrismore

Yeah, rtek 2.0 and yeah I think it has the ability to delete the OMP. I'm borrowing the ECU now so I'm going to keep my OMP hooked up. I can still disable it to eliminate the possibility.

I'm leaning toward the idea that plugging off the vent on the oil filler neck has created a vacuum in the engine until it causes a condition that keeps the engine from revving. I looked at the diagrams and it appears that is the only vent in the crankcase and shutting off the engine could be just temporarily releasing pressure. I can test tomorrow with the cap off.

satch

iTrader: (1)

What about a clogged cat. Usually they become most problematic when fully heated and not until then. You should be able to unplug the Oxygen Sensor as this should allow the exhaust to vent some and compare the results to the past experiences.

chrismore

Impossible because there is no cat. I'm leaning toward accidentally plugging the crank vent.

j9fd3s

iTrader: (3)

could be the gas tank vent too