I hope it's an easy fix

 

It wasn't the tune that changed, it was something else getting progressively worse, like maybe your spark plugs were starting to go bad etc..,

 

Did you check your car for any vacuum or boost leaks. I know my car ran like crap once I had the smallest leak and ran rich to a point it kept stalling out and would not go past a certain rpm you may want to check that too.

 

I'm going with bad gas, it won't burn and will foul the plugs. May also check your fuel filter too, I had a problem with my fuel system that did the same thing. It ran fine at first and progressively got worse and wouldn't stay running more than a few seconds.

 

They did get fouled, and I replaced them!

Leak free! Speed density isn't affected by air leaks like a MAF car is.

I will probably end up checking the fuel module like you did.
The only thing, is that bad fuel would not magically become good fuel when the engine warms up.

 

I am just confused. I got it to start with a sniff of starting fluid, but can only keep it going by going on/off throttle as fast as possible. It just pops and backfires...

Still holding 40-43 psi.

 

I had an issue similar to this. My MAP sensor took a ****. I too am on speed density and that's what it was for me. If you were on MAF, then this would be your MAF crapping out.

 

Good idea!
Were you on OEM MAP?
I am using Omnipower 4 Bar.

 

Any solutions yet?

 

If you have an AIT sensor check to make sure it is reading correctly, and make sure that it is not unpluged.

I had an AIT sensor fail on me, and caused my car to run a default Air Temp(AEM EMS).

You WB, or Narrowband O2 sensor might be going out.

 

My car is running off fuel temp, so there's no IAT.

I wisg I had ordered a spare 02 when I got my current one so I could check it quickly.

I did however forget to mention that my fuel pump does not prime when turning the ignition to on.
It does when cranking or running, though.

 

The pump not priming until you crank the engine over is normal. I thought it was odd but while installing my inline Walbro last week, I had to crank the engine over to make sure it was wired correctly and it gets no power to the pump until you crank the engine.

 

P0172 OBD-II Trouble Code
Technical DescriptionSystem Too Rich (Bank 1)

What does that mean?Basically this means that an oxygen sensor in bank 1 detected a rich condition (too little oxygen in the exhaust). On V6/V8/V10 engines, Bank 1 is the side of the engine that has cylinder #1.

Note: This DTC is very similar to P0175, and in fact your vehicle may show both codes at the same time.

Symptoms You will more than likely not notice any drivability problems, although there may be symptoms such as a misfire.

Causes A code P0172 may mean that one or more of the following has happened:

The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters can cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry.
There could be a vacuum leak.
There could be a fuel pressure or delivery problem
Possible SolutionsPossible solutions include:

Inspect all vacuum and PCV hoses, replace if necessary
Clean the MAF sensor. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner(DO NOT USE BRAKE CLEANER). Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
Inspect fuel lines for cracks, leaks, or pinches
Check the fuel pressure at the fuel rail
Check the fuel injectors, they may be dirty. Use fuel injector cleaner or get them professionally cleaned/replaced.
Check for an exhaust leak before the first oxygen sensor (this is unlikely to cause the problem, but it is possible)

 

I'll throw out a wild guess - have you verified your coolant temp sensor is reading properly in EVOScan? At least on my old DSMs, the dash temp gauge worked off a different sensor than what the ECU used and if the sensor was bad that was used by the ECU, the ECU would literally dump fuel in because it thought it was -55 F outside or something like that. Just a thought.

 

I was using an Omnipower as well. I switched to a GM 4 bar. Never had an issue sense.