Scratching my head...ran perfect and then..

[MZ3 SBC]

1979 930T Twin plug ( CDI) 3.4liter with k27 7200 built by Peter Dawe

I pulled the motor back in December to clean up the motor and detail the engine bay. It ran perfectly before pulling it out.....last week the motor went back in. I had some help on weekends which left me not paying to close attentions to some details that I had hoped were being looked after. But on to the point...the car did not start.

With the help of the community - I learned how to find TDC on cyl #1, index the rotor...verify it was not installed correctly and the timing was not right. now the distributor is right...and the car fires up on the first crank.......but immediately stalls out. It behaves as if it is not getting fuel.

I read countless threads and am working through the CIS primer. What I am reading is start with most basic.

Spark? yes
Fuel? we yes on crank for sure..car has 1/2 tank of fresh 93
Fuel pumps are humming
CDI boxes are whining
The vacuum lines are connected

if I spray starter fluid into the intake the car will idle few seconds longer then stumble into a stall.

It seems like the fuel is being shut off ....after cranking power.

I read something about the metering plate being hard to push down when fuel pressure is on......that would be the case with mine. very hard to push down when pumps are on, easy when pumps are off.

Any thoughts? CIS has so many components....the Fuel distributer was rebuilt few years ago ...but car has not been driven much at all.

I did have an occasional hot start problem last summer...other than than....car ran great.

[MZ3 SBC]

this really worries me....maybe the fuel is backing up.....and clogged at WUR or return line.

1979 930: Flushing fuel sytem on a 930 that has sat for 2 years

[MZ3 SBC]

Once I was told to check for vacuum leaks and air leaks from a friend and former 930 owner...I realized I made a big mistake by not putting the intake system back together.

Once it was buttoned up- the car roared to life!

Happy ending to a fun project.

I hope this thread helps the new guy.....best advice I read on this forum....check the basics...its usually one of those!


Super great resource was : Jims BAsement Workshop / CIS tutorial.

Notebook Spiral

[al lkosmal]

I'm not a Turbo expert..or a CIS expert...but I have had the opportunity to rebuild/debug a few recently. Have you checked your fuel system and control pressures? My experience is that when the pump(s) are off, there is no/little residual back pressure on the metering plate and when pump(s) are on there is some back pressure, but you still should be able to move the metering plate fairly easily and hear the injectors squeal as they fill with fuel...lifting the metering plate should not be very hard to do. if the pressure is too high, due to faulty pressure control or return line blockage and normal air intake/vacuum cannot lift the metering plate, the fuel dizzy will not route/meter fuel to the injectors...I.E. you can start on the cold-start injector or with a shot of starting fluid, but the paddle will not lift, the injectors will not fire and the engine will not keep running. I'd start with the pressure checks.
regards,al

[MZ3 SBC]

Once I buttoned everything up -she fired right up on first crank. AFR are definitely rich...and the timing is set to Z1 at moment...but its running!!

Thinking I missed a wire on the alternator....argh...gotta pull that out again.

tried upload short vid...but file is too big