I'm having an issue with my test coverage.  I recently built a trigger that doesn't allow anyone except for Sys Admins to insert or delete certain types of opportunities.  The triggers work fine, I just cant get the code coverage on my delete part.  Since I the reps can't insert the records, I'm thinking that's where it's failing, but in my test code I am testing it so a system administrator create the opportunity and then the standard user is deleting it.  Not sure why it's not working.

@IsTest
private class TestTrgCannotDeleteAcctMgmtRenewal
{
    static testMethod void testDelete()
    {
      Profile p = [SELECT Id FROM Profile WHERE Name='System Administrator'];
      User u = new User(Alias = 'sysadmin', Email='saplingsysadmin@testorg.com',
      EmailEncodingKey='UTF-8', LastName='Testing', LanguageLocaleKey='en_US',
      LocaleSidKey='en_US', ProfileId = p.Id,
      TimeZoneSidKey='America/Los_Angeles', UserName='saplingsysadmin@testorg.com');

      test.starttest();
      System.runAs(u) {
      
      try
           {
           Account a=new Account(Name='Test Account');
           insert a;

           Opportunity o = new Opportunity(Name='Test Opportunity',
           closedate=system.today(), stagename='Discovery',Type='Acct. Mgmt. Renewal',LeadSource = 'Marketing Mailer');
           insert o;
           delete o;
           }
           catch (Exception e)
           {
           system.debug('Error:'+e);

} 
         
        }
  test.stopTest();
      }


    static testMethod void testDeleteFail()
    {
      Profile p = [SELECT Id FROM Profile WHERE Name='Standard User'];
      User u1 = new User(Alias = 'standa', Email='saplingstandarduser@testorg.com',
      EmailEncodingKey='UTF-8', LastName='Testing', LanguageLocaleKey='en_US',
      LocaleSidKey='en_US', ProfileId = p.Id,
      TimeZoneSidKey='America/Los_Angeles', UserName='saplingstandarduser@testorg.com');
      
      Profile p2 = [SELECT Id FROM Profile WHERE Name='System Administrator'];
      User u2 = new User(Alias = 'sysadmin', Email='saplingsysadmin@testorg.com',
      EmailEncodingKey='UTF-8', LastName='Testing', LanguageLocaleKey='en_US',
      LocaleSidKey='en_US', ProfileId = p2.Id,
      TimeZoneSidKey='America/Los_Angeles', UserName='saplingsysadmin@testorg.com');

      test.starttest();
      System.runAs(u2) {
      
      try
           {
           Account a=new Account(Name='Test Account');
           insert a;

           Opportunity o = new Opportunity(Name='Test Opportunity',
           closedate=system.today(), stagename='Discovery',Type='Acct. Mgmt. Renewal',LeadSource = 'Marketing Mailer');
           System.runAs(u1){
           delete o;}
              // should throw an exception - the following assertion will cause an error if the code carries on
           }
           catch (Exception e)
           {
           system.debug('Error:'+e);

} 
         
        }
  test.stopTest();
      }
     
      
      static testMethod void testInsert()
    {
      Profile p = [SELECT Id FROM Profile WHERE Name='System Administrator'];
      User u = new User(Alias = 'sysadmin', Email='saplingsysadmin@testorg.com',
      EmailEncodingKey='UTF-8', LastName='Testing', LanguageLocaleKey='en_US',
      LocaleSidKey='en_US', ProfileId = p.Id,
      TimeZoneSidKey='America/Los_Angeles', UserName='saplingsysadmin@testorg.com');

      test.starttest();
      System.runAs(u) {
      
      try
           {
           Account a=new Account(Name='Test Account');
           insert a;

           Opportunity o = new Opportunity(Name='Test Opportunity',
           closedate=system.today(), stagename='Discovery',Type='Acct. Mgmt. Renewal',LeadSource = 'Marketing Mailer');
           insert o;
           }
           catch (Exception e)
           {
           system.debug('Error:'+e);

} 
         
        }
  test.stopTest();
      }

    static testMethod void testInsertFail()
    {
      Profile p = [SELECT Id FROM Profile WHERE Name='Standard User'];
      User u1 = new User(Alias = 'standa', Email='saplingstandarduser@testorg.com',
      EmailEncodingKey='UTF-8', LastName='Testing', LanguageLocaleKey='en_US',
      LocaleSidKey='en_US', ProfileId = p.Id,
      TimeZoneSidKey='America/Los_Angeles', UserName='saplingstandarduser@testorg.com');

      test.starttest();
      System.runAs(u1) {
      
      try
           {
           Account a=new Account(Name='Test Account');
           insert a;

           Opportunity o = new Opportunity(Name='Test Opportunity',
           closedate=system.today(), stagename='Discovery',Type='Acct. Mgmt. Renewal',LeadSource = 'Marketing Mailer');
           insert o;
              // should throw an exception - the following assertion will cause an error if the code carries on
           }
           catch (Exception e)
           {
           system.debug('Error:'+e);

} 
         
        }
  test.stopTest();
      }
      
}