So I drove my turbo Miata (MS2 1993 1.6) to work last week, and I’m getting ready to leave, and the car starts, but is unable to move. The Miata will idle perfectly at 1,300 rpm, but it will die if I press the throttle. It would also have 3 symptoms of idling. Either idle for exactly 15 seconds and die, idle for 2-3 minutes and die, or not even idle and crank up and die. And anytime I press the gas at all, it will die, revs won’t even build up. The car ran fine before hand, and didn’t have any issues. I have also noticed the AFR gauge is reading in just accessory mode, and reads ~14.5 but after a couple of seconds, it will spike up passed 18 and be unreadable. Some advice would be much appreciated!

 

Just a shot in the dark but... Does this coincide with depressing the clutch pedal? If so perhaps you are pinching your MAP hose under the dash

 

No it does not. Pressing down the clutch is the usual, doesn’t cause anything.

 

Is it possible that your TPS wires are loose or perhaps your throttle cable (seems unlikely.) So it doesn't even rev up if the clutch is out in neutral and you press the throttle? Does it go lean when you press the throttle?

 

Do you have good fuel pressure?

 

We tested the tps with a multimeter, and resulted it being okay. As for the throttle, any throttle causes the car to lean out and die very quickly, even by increasing it from the throttle body.

 

Yes, fuel pressure is good, tested that with a gauge, and pressure stays. Fuel pump is making its usual noise and filter has been changed recently.

 

How about revving up in neutral without touching the clutch pedal?

 

Unfortunately result is the same.

 

Is your MAP reading normal during this? If you post a log someone else might be willing to take a look.

 

Are you sure the MAP hose is still connected? I have heard of them blowing of inside the cases before

 

One last thought of the top of my head. I have had cell phone tuning apps corrupt the tune in my MS2 before.

 

Funny story, I just bought the Miata about 3 months ago right after moving, so I decided to make my first bad financial decisions as a 18 year old. So it was turboed and tuned by the previous owner, so after owning my stock miata for a while, I decided to learn turbo stuff. Long story short, I have yet to have a laptop to hook up to the MS2. The car has been turboed for a full year now with no issues. But I’ll definitely look into that hose, and a possible corruption.

 

Issue is now fixed! Turns out the issue was the MAP sensor in my MS2, it was reading vacuum even when Miata was off. So I had it delivered to diyautotune and they repaired it, now she drives!