What have you done to your MSP today?

[float_6969]

It sounds like weak spark/spark blow out to me. Every time I've seen a weak fuel pump, it would just lean out in the high boost/high RPM range and consistently misfire. Try lowing the boost. If it goes away with less boost, it's an issue with weak spark.

 

[Preferio]

It sounds like weak spark/spark blow out to me. Every time I've seen a weak fuel pump, it would just lean out in the high boost/high RPM range and consistently misfire. Try lowing the boost. If it goes away with less boost, it's an issue with weak spark.

One would think that if it's weak spark (new plugs, coils and wires BTW) the fuel mixture would be rich, not lean during the occurrence.

 

[Preferio]

I'd like to note that it will NOT occur in fifth gear. Obviously, it's a longer gear, so boost can't come on as fast.

 

[duffbuster243]

a missfire usually reads lean on a wideband as raw fuel is passing over the sensor which the wideband wont read.

 

[Preferio]

a missfire usually reads lean on a wideband as raw fuel is passing over the sensor which the wideband wont read.

So, it will cause a false-lean, then? I was curious about that, but assumed that there was enough heat in the combustion chamber to atomize/burn it enough so that it would not do that.

 

[Preferio]

Got a MIL! P0172: Fuel system too rich, bank 1. No other accompanying DTCs though.

 

[duffbuster243]

If you are on the stock ignition system, you need to upgrade. Stock coils are not strong enough. You could try closing the gap on your plugs to see it makes a difference.

 

[Preferio]

If you are on the stock ignition system, you need to upgrade. Stock coils are not strong enough. You could try closing the gap on your plugs to see it makes a difference.

I can't see the OEM ignition system not being able to handle my modifications and am fairly certain there are cars making substantially more power than mine on the OE system.

 

[duffbuster243]

16-19psi is a lot for stock coils, I know in the Miata world people experience spark blowout above 15psi and i know Miata ignition coils are stronger than the valve cover coils on the protege.

 

[Preferio]

I now have a P0172, FF: LTFT -25%, STFT, -7.8%, 2,672rpm, 5.78lb/m on my MAf

 

[shane02pro5]

I have been through several sets of coils but am close to 380whp for a considerable time without any ignition problems but I'm also pulling proper timing. Maybe need colder plugs gapped a little tighter. I couldn't imagine how fast that little thing hits full boost.

 

[Preferio]

I have been through several sets of coils but am close to 380whp for a considerable time without any ignition problems but I'm also pulling proper timing. Maybe need colder plugs gapped a little tighter. I couldn't imagine how fast that little thing hits full boost.

Hell, I've been through 3 sets in 35k miles and 28k of that was basically stock. When I say stock, I mean FMIC, SSAFC, and nothing more than 12psi (at least not any longer than a few seconds).

And it spins quick.

I have my plugs gapped at .030, but I'll shorten it to at least .028. I also have 4 or 5 extra coils that I'll swap out, too.

 

[Preferio]

The more I think about it, when I was having issues and going through plugs because at the time I was using AllData specs to gap them- listed it the same as the N/A Protg- the feeling was almost identical.

I'm going to check my MAF voltage, though, due to the DTC that's set.

 

[shane02pro5]

Once my boost got up there I had a real hard time not freaking out the maf sensor no matter how perfect the tune was... But you should be nowhere near that point but without having throttle pump adjustments I'm imagining your always going to be dipping lean.

 

[Preferio]

Cracked ceramic on #3!

 

[Preferio]

Well, glad that's taken care of.

 

[Preferio]

I say it all the time at work to my techs- start with the basics, don't assume a new part isn't bad, don't over-think things, etc...

 

[float_6969]

Glad you got it sorted out!

 

[Preferio]

Glad you got it sorted out!

Me too! Cool temperatures this morning on the way to work, the car screamed. I don't know how I was still getting 22mpg with it running the way it was.

 

[hornsfan10609]

Been giving the MSP a break from DD status for a bit, got my new ARP studs in the mail so I can replace the broken ones on the turbo mani. Can't wait to drive it and have it run like it's supposed to