i recently converted my 90 crx to obd1 running a neptune demon.

its a zc built for turbo, built quite well on a 6,000 budget, no dsm turbos here

my problem is its going into limp mode while running, the cel code is code 8, which is the tdc code. i put a obd1 distributor on for the conversion and suspected this to be the culprit, however, i rechecked the wiring and found it to be correct. the motor is in time.

what else could trigger this code?

 

That's not limp mode, since you can datalog and pull a code. That will, however, cause it to run incorrectly. I'm not sure what, other than the actual error, would produce that error.

 

i looked into code 8 which roughly translates to more of a misfire code. i assume it running in limp mode becasue it runs DECENTLY until it hits 3500ish then it hits a rev limiter

and no i did not set the rev limiter to 3500 so dont ask

im sure this is by far one of the broadest questions ever asked, but what could cause misfires like this? my plugs are rich, but not too rich, just on the safe side. its not the coil, just replaced the entire dizzy. the plugs are new, ive been cleaning them alot since ive been reading them, i have an enitre new ecu coming in the mail, ill try that next, and ill be picking up some plug wires............im really running out of things to check

 

You can datalog, right? If you can datalog, it's not a real limp mode. Limp mode runs off of a backup chip. If you're datalogging it is running the NepTune codebase.

There is a mode where the ECU can instigate a low rev limit and it's similar to limp mode, but runs off of the proper maps still and runs the code correctly, allowing datalogging etc.

I can't say for sure what's causing your issue.

 

im guessing the ignition, ill do the works then see

 

a code 8 is a bad sensor in the distributor.. Was the distributor you bought a used one?

 

You can also get this code with a bad ecu.

I just replaced wiring/dizzy in a prelude and nothing got the code to go away. And the dizzy was from a working car.

I changed the ecu and the code was gone and the car was running just fine again.

BTW (this has nothing to do with neptune as the car I was working with was running on it as well)

 

Had the exact same problem as you 93turbo16, found the distributor to be fine and it was the conversion harness plus a burned spot on the chipped ECU. Replaced both and went back to tuning. Also of interest was the fact that the OBD2a ecu ran the car fine with the suspected bad dizzy which led me to the harness and ECU.