large standard errors and coefficients

[delcredere]

dear all, estimating a system of 3 equations by gmm. however my estimation output shows really large standard errors and coefficients. please what can i do to correct this? below is my output.
System: SYS01FIRSTATTEMPT
Estimation Method: Generalized Method of Moments
Date: 02/15/13 Time: 12:59
Sample: 1 490
Included observations: 369
Total system (unbalanced) observations 1040
Kernel: Bartlett, Bandwidth: Fixed (6), No prewhitening
Linear estimation after one-step weighting matrix

Coefficient Std. Error t-Statistic Prob.

C(1) 8380290. 23648450 0.354370 0.7231
C(2) -11473393 7854625. -1.460718 0.1444
C(4) -1138255. 2194419. -0.518704 0.6041
C(5) 0.086240 0.018126 4.757781 0.0000
C(6) 124421.4 288494.6 0.431278 0.6664
C(7) 75992.66 210637.4 0.360775 0.7183
C(9) 12250520 9081384. 1.348971 0.1776
C(11) -1.23E+08 32439575 -3.804226 0.0002
C(12) 11697677 2900992. 4.032302 0.0001
C(13) 9312367. 1134972. 8.204930 0.0000
C(14) -14285.14 7746.818 -1.844001 0.0655
C(15) -17015337 33225236 -0.512121 0.6087
C(16) 1012670. 892254.6 1.134957 0.2567
C(20) -1.72E+08 20159558 -8.552999 0.0000
C(21) -98991.23 1552750. -0.063752 0.9492
C(23) 0.048540 0.020147 2.409310 0.0162
C(24) 12.34926 0.645249 19.13875 0.0000

Determinant residual covariance 5.36E+47
J-statistic 0.123410


Equation: GDP=C(1)+C(2)*GDP(-1)+C(4)*LOGDSV(-2)+C(5)*CAPFLOW(2)
+C(6)*RES(-1)+C(7)*HCAP(-1)+C(9)*GCAP(-1)
Instruments: GDP(-1) LOGDSV(-2) CAPFLOW(-2) RES(-1) HCAP(-1)
LOGEDS(-2) TOT(-1) FIS(-1) EXR(-2) RIR(-1) OPEN(-1) CAPGDP(-1)
CAPDEBT(-1) C
Observations: 308
R-squared -154726985367552.00 Mean dependent var 2.936321
Adjusted R-squared -157811241648128.00 S.D. dependent var 4.063834
S.E. of regression 51051072 Sum squared resid 7.84E+17
Durbin-Watson stat 0.582977

Equation: LOGDSV=C(11)+C(12)*GDP+C(13)*LOGEDS(-1)+C(14)*EXR(-1)
+C(4)*LOGDSV(-2)+C(15)*TOT+C(16)*FIS+ C(6)*RES(-1)
Instruments: GDP(-1) LOGDSV(-2) CAPFLOW(-2) RES(-1) HCAP(-1)
LOGEDS(-2) TOT(-1) FIS(-1) EXR(-2) RIR(-1) OPEN(-1) CAPGDP(-1)
CAPDEBT(-1) C
Observations: 363
R-squared -2036622757462015.9 Mean dependent var 4.560112
Adjusted R-squared -2076781506985984.1 S.D. dependent var 1.661233
S.E. of regression 75705232 Sum squared resid 2.03E+18
Durbin-Watson stat 0.944618

Equation: CAPFLOW(-1)=C(20)+C(5)*CAPFLOW(-2)+C(12)*GDP+C(13)
*LOGEDS(-1)+C(21)*RIR+C(23)*CAPGDP(-1)+C(24)*CAPDEBT(-1)+
C(6)*RES(-1)
Instruments: GDP(-1) LOGDSV(-2) CAPFLOW(-2) RES(-1) HCAP(-1)
LOGEDS(-2) TOT(-1) FIS(-1) EXR(-2) RIR(-1) OPEN(-1) CAPGDP(-1)
CAPDEBT(-1) C
Observations: 369
R-squared 0.802551 Mean dependent var 2.73E+08
Adjusted R-squared 0.798722 S.D. dependent var 4.50E+08
S.E. of regression 2.02E+08 Sum squared resid 1.47E+19
Durbin-Watson stat 0.742112