IIS 8 Multithreading and Crashing App Pool

I have a basic SOAP based web service that has a method to retrieve an image from a database, save it to a local directory, and return the path to the image. This is hosted in IIS 8.5 on Windows Server 2012R2 with a single core 2.3 GHz processor.

This application runs fine for single threaded calls; however, every morning we have a batch job that sends a few dozen or so requests to the service and causes RFP to kick in and restart the app.

I've tried changing the service behavior in the config file to the bare minimum

    <behavior name="serviceBehavior"> 
      <serviceThrottling  maxConcurrentInstances="1" maxConcurrentSessions="1" /> 
    </behavior>

but the app still crashes. Here is a clip of the WER file from the App crash:

FriendlyEventName=Stopped working
ConsentKey=APPCRASH
AppName=IIS Worker Process
AppPath=C:\Windows\SysWOW64\inetsrv\w3wp.exe

I used a 3rd party tool called SoapUI to perform some load testing and the error it sees on the requesting end is:

java.net.SocketException: Connection reset

My question is whether this is something that can even be controlled by the web service or if this expands to more of a networking/hardware level?

EDIT: To clarify on some points the w3wp.exe application crashes and gets a new PID when it restarts. Here is the repeated output in the Event Viewer during the crashes.

Faulting application name: w3wp.exe, version: 8.5.9600.16384, time stamp:         
0x52157ba0
Faulting module name: unknown, version: 0.0.0.0, time stamp: 0x00000000
Exception code: 0xc00001a5
Fault offset: 0x069d1e99
Faulting process id: 0x3e44
Faulting application start time: 0x01d3c4dab9cec060
Faulting application path: C:\Windows\SysWOW64\inetsrv\w3wp.exe
Faulting module path: unknown
Report Id: a605ce41-30da-11e8-80ce-005056a725cd
Faulting package full name: 
Faulting package-relative application ID: