So it's been quite a while since I've had my MSPNP installed in a miata but I recently re-swapped my motor and re-installed it. I have the same setup I had about 2 years ago a 94 1.8 motor in a 91 miata on the 91's wiring harness with a 90-93 MSPNP. The car is running well, good idle, nice afr's for the most part. However I am having issue with the car when I am barely on the throttle. Once the car warms up 160+ it gets really wonky when I am at any rpm and lightly on the throttle. It jumps erratically like the spark or fuel is cutting out not quite sure what is going on. I've included a datalog of it occuring and my tune. Any suggestions would be appreciated!

 

Mine does the same thing, but it clears up above 2.5k rpms and only does it sometimes.

 

I'm thinking maybe my TPS is just really touchy/dirty when I'm barely on it. Could you post a datalog & msq of yours doing it Greg, maybe it'd help if I have something to compare mine to as well.

 

hi there, did you sort this problem out?

I have exactly the same problem, not sure what it could be....nothing shows up on the datalog.

Cheers

 

under basic settings > engine constants. Change injector staging to alternating.

 

As brain said, and then have fun re-tuning completely

How did that get set to simultaneous?

 

Umm, maybe not quite the same problem for me then....I had my injector staging set to alternating.

My car has a random stumble which is normally below boost levels, my tune other than that is quite good.
I have used Tunerstudio autotune to tune and my afr,s are good in and out of boost.....just got this jerky stumble to sort out and thats about it.

By the way I have changed the plugs,leads and coils.

Cheers

 

check your idle voltage - the replacement engine may have an alternator going out. Hesitation at low RPM, esp. low throttle, is a symptom of low voltage. Any difference with headlights on? What about when you turn on your A/C as well (which turns on both radiator fans by default)?