diff --git a/Cantera/src/numerics/BEulerInt.cpp b/Cantera/src/numerics/BEulerInt.cpp
index 154a89d7f..78753267d 100644
--- a/Cantera/src/numerics/BEulerInt.cpp
+++ b/Cantera/src/numerics/BEulerInt.cpp
@@ -656,7 +656,7 @@ namespace Cantera {
       /********************************************************************
        * Call the function to get a jacobian.
        */
-      m_func->evalJacobian(time_curr, delta_t_n, y, ydot, J, f);
+      m_func->evalJacobian(time_curr, delta_t_n, CJ, y, ydot, J, f);
 #ifdef DEBUG_HKM
       //double dddd = J(89, 89);
       //checkFinite(dddd);
diff --git a/Cantera/src/numerics/IDA_Solver.cpp b/Cantera/src/numerics/IDA_Solver.cpp
index 91a5532a1..7c269b040 100644
--- a/Cantera/src/numerics/IDA_Solver.cpp
+++ b/Cantera/src/numerics/IDA_Solver.cpp
@@ -66,6 +66,13 @@ extern "C" {
    *  the sundials data types N_Vector, etc.), we define this function as the single function that IDA always calls. The
    *  real evaluation of the residual is done by an instance of a subclass of ResidEval, passed in to this
    *  function as a pointer in the parameters. 
+   *
+   * FROM IDA WRITEUP -> What the IDA solver expects as a return flag from its residual routines ------
+   *   A IDAResFn res should return a value of 0 if successful, a positive
+   *   value if a recoverable error occured (e.g. yy has an illegal value),
+   *   or a negative value if a nonrecoverable error occured. In the latter
+   *   case, the program halts. If a recoverable error occured, the integrator
+   *   will attempt to correct and retry.
    */
   static int ida_resid(realtype t, N_Vector y, N_Vector ydot, N_Vector r, void *f_data) {
     double* ydata = NV_DATA_S(y);
@@ -74,8 +81,15 @@ extern "C" {
     Cantera::ResidData* d = (Cantera::ResidData*) f_data;
     Cantera::ResidJacEval* f = d->m_func;
     Cantera::IDA_Solver *s = d->m_solver;
-    f->eval(t, ydata, ydotdata, rdata);
-    return 0;
+    double delta_t = s->getCurrentStepFromIDA();
+    // TODO evaluate  evalType. Assumed to be Base_ResidEval
+    int retn = 0;
+    int flag = f->evalResidNJ(t, delta_t, ydata, ydotdata, rdata);
+    if (flag < 0) {
+      // This signals to IDA that a nonrecoverable error has occurred.
+      retn = flag;
+    }
+    return retn;
   }
 
   //! Function called by by IDA to evaluate the Jacobian, given y and ydot.
@@ -102,7 +116,9 @@ extern "C" {
     Cantera::ResidData* d = (Cantera::ResidData*) f_data;
     Cantera::ResidJacEval* f = d->m_func;
     doublereal * const * colPts = Jac->cols;
-    doublereal delta_t = 0.0;
+    Cantera::IDA_Solver *s = d->m_solver;
+    double delta_t = s->getCurrentStepFromIDA();
+    // printf(" delta_t = %g 1/cj = %g\n", delta_t, 1.0/c_j);
     f->evalJacobianDP(t, delta_t, c_j,  ydata, ydotdata, colPts, rdata);
     return 0;
   }
@@ -241,6 +257,12 @@ namespace Cantera {
     m_tstop = tstop;
   }
   //====================================================================================================================
+  doublereal IDA_Solver::getCurrentStepFromIDA() {
+    doublereal hcur;
+    IDAGetCurrentStep(m_ida_mem, &hcur);
+    return hcur;
+  }
+  //====================================================================================================================
   void IDA_Solver::setJacobianType(int formJac) {
     m_formJac = formJac;
     if (m_ida_mem) {
diff --git a/Cantera/src/numerics/IDA_Solver.h b/Cantera/src/numerics/IDA_Solver.h
index 4bf250161..928728969 100644
--- a/Cantera/src/numerics/IDA_Solver.h
+++ b/Cantera/src/numerics/IDA_Solver.h
@@ -109,6 +109,12 @@ namespace Cantera {
      */
     virtual void setStopTime(doublereal tstop);
 
+    //! Get the current step size from IDA via a call
+    /*!
+     *   @return Returns the current step size.
+     */
+    virtual double getCurrentStepFromIDA();
+
 
     //! Set the form of the jacobian
     /*!
diff --git a/Cantera/src/numerics/NonlinearSolver.cpp b/Cantera/src/numerics/NonlinearSolver.cpp
index 64394870f..89a2904a0 100644
--- a/Cantera/src/numerics/NonlinearSolver.cpp
+++ b/Cantera/src/numerics/NonlinearSolver.cpp
@@ -2979,6 +2979,7 @@ namespace Cantera {
     int info;
     doublereal ysave, ydotsave, dy;
     int retn = 1;
+    
     /*
      * Clear the factor flag
      */
@@ -2987,7 +2988,7 @@ namespace Cantera {
       /********************************************************************
        * Call the function to get a jacobian.
        */
-      info = m_func->evalJacobian(time_curr, delta_t_n, y, ydot, J, f);
+      info = m_func->evalJacobian(time_curr, delta_t_n, CJ, y, ydot, J, f);
       m_nJacEval++;
       m_nfe++;
       if (info != 1) {
diff --git a/Cantera/src/numerics/ResidJacEval.cpp b/Cantera/src/numerics/ResidJacEval.cpp
index 247f46e5c..a0261c9f3 100644
--- a/Cantera/src/numerics/ResidJacEval.cpp
+++ b/Cantera/src/numerics/ResidJacEval.cpp
@@ -328,17 +328,13 @@ namespace Cantera {
    * @param resid         Value of the residual that is computed (output)
    */
   int ResidJacEval::
-  evalJacobian(const doublereal t, const doublereal delta_t,
+  evalJacobian(const doublereal t, const doublereal delta_t, doublereal cj,
 	       const doublereal * const y,
 	       const doublereal * const ydot,
 	       SquareMatrix &J,
 	       doublereal * const resid)
   {
     doublereal * const * jac_colPts = J.colPts();
-    doublereal cj = 0.0;
-    if (delta_t > 0.0) {
-      cj = 1.0/delta_t;
-    }
     return evalJacobianDP(t, delta_t, cj, y, ydot, jac_colPts, resid);
   }
   //====================================================================================================================
diff --git a/Cantera/src/numerics/ResidJacEval.h b/Cantera/src/numerics/ResidJacEval.h
index b44707ec9..678d3fe7b 100644
--- a/Cantera/src/numerics/ResidJacEval.h
+++ b/Cantera/src/numerics/ResidJacEval.h
@@ -318,6 +318,7 @@ namespace Cantera {
      *
      * @param t             Time                    (input) 
      * @param delta_t       The current value of the time step (input)
+     * @param cj            Coefficient of yprime used in the evalulation of the jacobian
      * @param y             Solution vector (input, do not modify)
      * @param ydot          Rate of change of solution vector. (input, do not modify)
      * @param J             Reference to the SquareMatrix object to be calculated (output)
@@ -327,11 +328,9 @@ namespace Cantera {
      *            1  Means a successful operation
      *           -0 or neg value Means an unsuccessful operation
      */
-    virtual int evalJacobian(const doublereal t, const doublereal delta_t,
-		             const doublereal* const y,
-			     const doublereal* const ydot,
-			     SquareMatrix &J,
-			     doublereal * const resid);
+    virtual int evalJacobian(const doublereal t, const doublereal delta_t, doublereal cj,
+		             const doublereal* const y, const doublereal* const ydot,
+			     SquareMatrix &J, doublereal * const resid);
 
     //! Calculate an analytical jacobian and the residual at the current time and values.
     /*!
@@ -339,6 +338,7 @@ namespace Cantera {
      *
      * @param t             Time                    (input) 
      * @param delta_t       The current value of the time step (input)
+     * @param cj            Coefficient of yprime used in the evalulation of the jacobian
      * @param y             Solution vector (input, do not modify)
      * @param ydot          Rate of change of solution vector. (input, do not modify)
      * @param J             Reference to the SquareMatrix object to be calculated (output)