Remote start on 2007 TRD 4x4 remote start turns engine over but won't start.

Can anyone help me on 2007 Tacoma 4x4 TRD? My remote start turns engine over but does not start. It was working. if I put key in it starts without turning.

 

you didn't install one of the anti-theft bypass kits

Directed Electronics Inc PKALL Xpress Kit Data Transponder

http://www.amazon.com/Directed-Electronics-PKALL-Xpress-Transponder/dp/B001N7RE44

If I remember correctly from my install some 5 yrs ago, there's three wires that tie into the alarm (power, ground, and a negative out while starting) and three wires that tie into the factory key cylinder (one that ties into a signal wire, and the other two split another), and there's a little bit of archaic programming (ignition on/off with key in and button pushing kind of thing).

It's really no worse than installing the remote start itself

 

It was installed at dealer or came from factory. It has worked until last year,I think it may be a switch or programming.

 

Then my suggestion is to take it back to the dealer, or at least to a reputable car stereo installation shop and ask them to dig into it... that's assuming you lack the skills and knowledge to troubleshoot it yourself.