does the pfc have a safe mode? and if so what could trigger it?

 

One "safe" mode is the same as the stock ecu, MAP sensor not connected will cause the engine to run way too rich.

You can also get that way by selecting one of the "OPTIONAL" map sensor screens. Page 24 of the manual. This should also place it into running too rich.

 

my cars front leading plug is firing at random intervals. The plugs, coils, and wires are all fine so i'm trying to rule out the pfc. Is there any way that the pfc could make that plug fire insanely?

 

Since both leading plugs fire in series at the same time, if the leading coil or ignitor or other wiring was bad; both would misfire as the same time.


If only the front leading plug is misfiring, then only that plug is bad.

 

i'm having many issues with this car, the rpms won't go any higher than 2k. When it hits 2k the commander reads 0.0% injector duty.

 

I also just replaced all the plugs and wires and checked the coils while i was in there and the coils checked out fine

 

i'm an idiot, i forgot to plug in the tps

 

No your not! It is just a case of temporary brain fade.

 

I have been helping ThirdGen, unsuccessfully, on the 7 so I though I would throw some stuff in here.

The whole random firing was just kinda made up I think. We pulled the wires today and they both discharged almost normaly. When the rear leading wire was pulled the arc was much quieter than the front leading. The front could be heard while sitting in the car but. my ear had to be in the bay in order to hear the rear. They were no longer randomly firing, I dunno why we heard that before.


I am just gonna list all of the problems and stuff we have checked. I will probably forget some stuff.

First the car idles like crap and has a serious loss of power. Sounds like it is missing but everything is firing. The idle only varies by about 100 rpms until it gets warm and then it dies. Pulling leading plug wires does nothing, it runs basically the same if one is pulled. We have not tried both.

Rich at idle but not really drowning in gas.
I think there is more but I can't remember.

So far we have replaced the plugs and wires. Checked the coil and boost sensor. Kinda checked the ignitor. Reset the ignition map to one for a near stock non-sequential map(the orginial settings we far from both this and stock). Pluged back in the TPS, whoops.

Nothing has had any effect on the way it idles. The PFC is showing that at idle it is 5 and 20 ATDC, according to the map it should be something other than this, 8 and 17 I think. We have not had a light on it yet to make sure the PFC is correct.

I am totally lost on this one, hopefully all of this adds up to somthing. Oh where is the map sensor and how would we test it? We could find no reference to it in the FSM. Also economics sucks as do macs.

 

It is located on the driver's side firewall, and has a sticker on it that says "SENSOR - BOOST". You'll need to apply vacuum/pressure to the sensor with a hand pump and measure the resulting voltage. You can see the voltage on the PFC Sensor/SW Check screen (labeled PIM). Use the table below to see the correct tolerances.

 

Whoops I am feeling dumb again. I just assumed the boost sensor was different from the Map sensor. At around 420mmHg it was 1.62v, I think, so I guess it is a little high.

When we put the intake back on the first time we forgot to connect the Map sensor and it did run even worst than it does currently. Once the PFC reverts back to the stock settings does it have to be reset to get out of that Mode? To me it seems to still be running on factory settings. Thanks for the info on the Map sensor.

 

Let's start over from the beginning. Was the PFC installed only recently? Were all these problems non-existant before the PFC?

Yes, having the MAP sensor disconnected causes the car to run very poorly.

"Once the PFC reverts back to the stock settings does it have to be reset to get out of that Mode? To me it seems to still be running on factory settings."

I don't quite understand what you mean by stock/factory settings and reverting back to them. (?)

Longshot: as Chuck mentioned, make sure you are on "1. Normal" on your PIM Volt setting screen (page 24). I had a bad/surging idle when I installed my PFC because I had accidently backed out of the screen with #2 selected.

Also, I just realized something. We suspect there to be a conversion error when the Commander displays vacuum/pressure from the MAP sensor. The most accurate way to measure would be with a separate volt meter.

 

Sorry, some back ground would really help. The rough idle started after a little race with a vett. Next time he came to a stop the idle was as described above. The PFC had been in for a while before that.

I will definately check the PIM volt screen tomorrow. Thanks for that hint. I guess the things that really seem odd to me is that a leading plug wire being dissconnected has no ill effect on the idle. The other thing is that the idle does not surge at all. It just happens to sound like a bridgeport!

The Map was checked with a volt meter while the autometer guage read about 10.5-11 psi vac which should be about 568mmhg, so that sounds a little better.

Thanks for all your help.

 

If all was fine until after a race, I suggest you get the compression checked.