For some reason, my 93' is running fine while it's 85 out, but not when it's 60-65 out when it will bog after entering closed loop for a minute to two minutes. Any ideas?

 

Sounds like you've angered the Miata Fairy...Time for a human sacrifice.

 

A goat won't work?

 

Maybe a pony?

But seriously...you need to provide more info on your car if you want someone to get to the bottom of your quandary.

 

IAT corrections off ?

 

Stock ECU with Bipes. Greddy kit with no mods. I've replaced or swapped the ECU, ISCV, FPR, AFM, ECT, yahda, yahda, yahda.

This first occurrence was about 8 months ago. Maybe 15 seconds of bogging when hitting closed loop. It was so intermittent that I didn't bother checking it. Gradually it started happening more often, mostly when I ran, turned off for a little while, then ran again.

Now it happens almost all the time, except when it's hot outside. Sometimes for 10 to 30 seconds, sometimes all the time till the engine is up to temp.

I have a MSPnP I plugged in. One time the MAT and ECT gauges went bonkers, reading all over the place but mostly pinned. The next time. Normal.

Maybe wiring? But why temp related? No CELS. I got a couple when it first started happening, but lost them in a battery run-down.

 

there's your problem

 

What are your afr's doing when its acting up?

 

I don't have a log yet. Just got around to using the MSPnP to diagnose. And the Bipes has been removed and the problem remains. Ran all day today in the heat (90'ish). No issues, though I'm not convinced I'm running in closed loop.

 

Since we are playing the guessing game I guess cat?

 

CAT is relatively new as well... Tis a thought though.

 

it's an easy thing to check but if it's pretty new then it probably isn't

 

Leave it in open loop for the time being on the MS and also try cleaning the throttle body and check your timing. If its cold out and the engine it warm does it still run like ****. Hard to see why ambient temps would have that much affect on it.

 

I cleaned the throttle body. As a matter of fact, I got one off of a 70k wreck and replaced it. I know the ambient temperature thing makes no sense. But it absolutely is true. Or a multiple incident coincidence. Every day it's been in the 80's or greater, I've had no issues.

 

Also, I've gone through everything easy like timing, plug, wires, vacuum, etc.

 

I don't know much about the bipes but fuel trims are definitely dependent on temperature in most cases. The colder it is outside the more fuel will be used. Maybe you need to retune your car for cooler weather?

 

I get the problem without the Bipes installed. It really does nothing but pull timing at higher RPMs and I have it set to start pulling timing well-above the RPM range in question. I'll be back out there today. (I work on in on the street in SF) Have to take a tire off that went flat.

 

I left the ECT connector off and got the worst-case symptoms. I'm going to check the fuel injection harness.

 

Hey dude let me know if you find the issue. My wires are fine as far as I can tell (and I could have even done something wrong checking them) and my car still hates my ECT sensor.

 

Shall do. I measured continuity from both the harness plug and the connector but still had the problem. Both measured fine. Maybe I needed the ECU to throw a CEL before it would forgive the ECT for its past transgressions... Try pulling the wire, running it and plug it back in. Stranger things have happened.

Maybe just jostling it around... Maybe it will start bogging again tomorrow.