[urq] 84 urq no crank

[Buchholz, Steven]

... the ignition driver is the same on both ... have very many folks had
this fail?  For me on the ury and 4kQ the coil driver seems pretty
robust.  

I agree with Ingo on checking the timing at the distributor ... line up
the crank on TDC compression #1 and make sure the distributor rotor is
pointed at the mark on the lip of the distributor housing.  I also have
concerns about supply and ground ... I know you checked the smaller
grounds, but what about the large braid that connects the block to the
frame of the car (near the left motor mount)?  I think Tony may have
suggested the ignition switch before ... that is another good candidate.
In fact, one thing I recommend if possible is to charge the battery up
well, manually activate the fuel pump relay for a few seconds, turn the
ignition key to the running position and see if you can't bump start the
car in 2nd gear.  If this works than you either have a low supply
voltage situation at the ECU due most likely to the ignition switch, or
a poor ground at the engine block.  The starter can really draw down the
voltages if there is a connection issue ... 

Steve B
San Jose, CA (USA)

> >
> > I'm a little concerned with the way that the computer and 
> ignition module
> > were checked.
> > Most electrical problems occur after a heat soak or after 
> the part has
> been
> > under a electrical
> > load for a period of time. I don't know how your parts were 
> checked, but
> in
> > most cases statically
> > testing them can lead to false results. The only true test 
> for such a
> parts
> > is  to test them dynamically (i.e. under  a load condition.)
> > Based on what your saying with regards to spark no spark until the
> ignition
> > key is cycled ,and the fact that the
> > tach is bouncing .  I would definitely start my diagnosis 
> by changing the
> > ignition module.  I believe a regular coupe/
> > 4000 one will work just fine.