I have a 1992 toyota and it is very hard to start, some times it stop in the middle of the road and won't start unless you spray it with with a starter spay. It has been at the Toyota Dealers for two days now and they can;t find the problem with it. It is in San Diego

Hi,
This is usually due to warped/worn brake discs/rotors. Time to have a brake job done.

It could also be the wheel bearings. It will require a mechanic to fix.

Td

I suspect a clogged fuel filter. Having lived on bumpy rural roads for years, I has to change the filter on my '86 Sunbird 3 or 4 times.

Could be a sensor. Have it scanned would be my suggestion.

There are usually two to three transmission sensors on most vehicles
sounds like it may have gotten damaged possibly hitting something in the road. You could take it to Autozone they may be able to help you locate the bad sensor. Or call them.

i take it its a diesel. and when it stops does it start straight away or does it take time

check the fuel filter first , then the fuel pump

Go to the basic first,for the injector to fire the EFI fuse has to not be opened,injector will have +B on one side and a ground signal from ECM. You dont need to jump it,you need to verify power, then verify signal. check for power first, then check for signal. If there is no power youll trouble shoot from there, then you ll need to check for signal, the signal is generated in the disributor this is called a pick up. First the power the power is from the ignition switch to the igition coil, because you have spark there is no reson to check for power.What gets me is you have spark but no injectors ,your basically need to trouble shoot a open wire condition

Check if you have spark & fuel when this happens. Are you sure its a carbureted engine?

check for fuel delivery, remove fuel inlet line on fuel rail &placed in a container turn ignition on ,you should have fule flowing if not check fuel pump,ignition timing may also be of, check with timing lighty

check for a failed cat converter
run the fault codes as items that look good seldom are