Troubleshooting a Toyota Sewing Machine?

There are many reasons for uneven stitching. The most common reason for uneven stitches:
1. Old or inferior or unsuitable thread.
Use good quality threads
2. Fabric is being pulled while sewing.
When sewing it is important to remember to never pull the fabric - allow the fabric to be taken up by the sewing machine.
3. Bad maintain the sewing machine.
Clean and lubricate your sewing machine.
4. There is a malfunction in the bobbin or bobbin is incorrectly threaded in the bobbin case.

Check to see if there are scratches on the bobbin and replace it if there are. The same goes for a worn bobbin. Replace the bobbin. Check to see if the bobbin and the bobbin case have been inserted correctly. You should hear a click when it is. The bobbin needs to be wound correctly. Rewind if it isn't.
5. Wrong thread tension.
Make sure you have the right tension setting. Set tension correctly for different fabrics
6. Problem with the needle.
Check that the needle is not bent or that the end of the needle is blunt. If necessary, replace the needle.
7. The needle hole in the needle plate is damaged.
Make sure there are no scratches around the needle hole in the needle plate. If necessary, replace the needle plate with a new one.
8. Check the presser foot.
Make sure there are no scratches around the hole in the presser foot and that the presser foot you are using is appropriate for the stitch that you want to sew.

Have you been using your machine and this just started to do this? or has your machine been unused for a while and this is how it started this time?

Has your machine been cleaned lately?
Just some question you'll probably be asked if you ask for help on one of the sewing forums.
There are several excellent sewing forums with members who know what questions to ask and can provide excellent instructions to get your machine sewing again.
Try joining these groups and you'll be very glad you did:

www.quiltingboard.com/.../
sewing.patternreview.com/.../96897