After rebuild 13b will not start,do you know why
 

Hey all,,I'm a 1st gen 12a guy,,with a friend who has rebuilt
his 1986 13b,,with new plugs the front are clean while both
rears are wet , dirty,and it doesn't smell like gas,it trys to start
but then blows back through the butterflys,i said 180' degrees
out,at least thats what it acts like...what do you think ????

i rebuilt my t2 and it would not start either we replaced the computer then it started up and we left it for a whie and it does not want to start up on its own fuel.

I read another thread that talks about no fuel on it's own,,is that
a common problem with the FI ?? the 86 has fuel and the guy
replaced the fuel regulator,,,$86.00 bucks for that thing,,I'm asking,,because this guy is starting to do things and look in areas
that(i think) don't relate to the problem,it's not getting fuel,,,,,,,
bottom line,reading the books just confuses,,i mean there is a lot
of plumbing,and wiring,,I'm just trying to help him before he ruins
it,,,i know whats up,but the mazda FI is new to me,,,being a 12a
owner,,how about removing the battery cable,then put back on,,
does that reset the system ???all fuses are ok too,,and are the
1st gens pretty much the same as the 2ed gens ????wiring ???

What do you think ???

Thanks.,.

When I rebuilt my '86 I had the EXACT same prolbem, it turned out that the primary fuel injector was not working. The harness had become so brittle that the wire accually snapped while removing the engine, maybe a similar thing is happening there.

OK,,,When or HOW does a fuel regulator act when going out ??
,,,,is it,that when they fail,,it's"stuck" open,,,or shut ?? Looked
at fuel injector wiring,and yes,not to good of shape,i hope he
takes care of that,And does the vacume line to the regulator
(fuel) have to generate a large PSI or small ??? To prime FI,,
does the whole system have to be evacuated ??

Thanks Again

On RX-7 fuel injected cars, fuel is pumped to the injectors. Unused fuel is returned to the gas tank. The pressure regulator maintains a specific pressure by bleeding off fuel to the return line as necessary, since the fuel pump is a constant volume device. If it fails, it leaks, meaning it bleeds too much fuel back to the tank, and thus pressure to the injectors is low.

The vacuum line to the regulator does not have to have a certain vacuum at all. It is used to control pressure. At idle (High vacuum) the pressure is about 28psi. Pull the vacuum hose (sumulating WOT), the pressure increases to 37-39 psi. The regulator is going to pick one of these 2 pressures depending on how much vacuum it senses, but I don't know the exact crossover point.

The only thing necessary to prime the fuel system is to short the fuel pump test connector and turn the ignition on. This is a 2-wire connector located in the engine compartment on the passenger side (nothing connected to it). It is green, I believe.

You probably should get a fuel injection pressure tester, the 9psi max on a regular vacuum/fuel pump tester is not going to hack it. ;) :D Good luck!

Irv, Keith's dad

It probably is just being "stubborn." A freshly rebuilt rotary is usually hard to start. Try the ATF trick. Or pull start it with another vehicle.

Brad