RE: [T3] Newbie--Car Won't Start EFI troubleshooting procedure l ong

["Martinez, Leon" <martinezl@ftscpac.navy.mil>]

Christopher J. Valade ,

I wrote some EFI procedures before, looke in the
forum archives but hear goes some info from the 
top of my head.

The problem of not starting can be caused by a number 
of problems. You say this car is a 1970 with EFI and 
it stopped working when the foot was taken off the 
accelerator ? or was it the clutch pedal ? Sudden 
lunging may get some old wires in the harness to 
disconnect or break. old wiring harnesses do that and 
boy did I have your problem before, I changed coils and
plug wires to no avail . After I fixed my wiring , the
problem never came back.


I had to first make sure the engine got it's spark and was 
statically timed right (timing adjusted with engine off),
then I made sure the pump worked by having someone turn the 
key all the way on and off while I was phyiscally feeling 
the pumped for detectable vbration or movement which could 
indicate power is getting to it or it works, when no movement 
or sound was detected I bypassed the two wires with my own 
hooked up directly to the battery and the other to the car's 
body/chassis, still no movent then pump is bad . With 
a good pump, relay and wiring, the pump should only move 
for a couple of seconds without actually turning the engine,
that is when the key is in the 'on' position with the oil and
gen light on and when you crank the engine and engine starts 
then the pump would keep going continually. This controlled
by the computer. 

Next I fixed the cold start injector that was always on and kept
flooding the engine, it would not start in this condition and 
the engine would stop turning since the cylinders were filled 
with gas. I found this by removing my spark plugs, they were 
always wet. The injector was leaking greatly and it was hooked
up improperly, one side + hot should be hooked up to the starter
solenoid where the key 'crank' power comes in and the other 
to the cold start injector temp sensor, mine was hooked up to the 
engine case and always injected even when hot.


On the "C" brain (numbers on it with a "C".
I think the 1970 injection system had a fuel enrichment system 
similar to the carburator squirt pump but electronic.
With the key in the 'on' position you can hear a series of 20 
squirts or clicks comming from the injectors everytime you step 
on the foot pedal all the way down, it would be easier if you did 
pump the lever manually at the intake so you can feel and hear
the injectos two injectors should only inject at any given engine 
position and should always be on opposite ends diagonally.
You can prove the injectors are squirting by removing them with 
a little 10mm socket and a 1/4 in rachet. Without unplugging them 
put a pair in a coffee can or jar and see if one squirts when 
you 'pump' but remember to remove the wires from the coil, 
you do not want any fires. After verifying that one works, turn the 
engine a little maybe from 1/2 to 3/4 turn, the other should squirt 
when the accelerator is pumped.

Do the same to the otherside. If no squirt is detected then look 
at the wires and connectors that go to the injector, if no injector 
is working eventhough the ignition is on and you are pumping, then 
check the injector points and connections below the distributor.

If that is all good, you may not have fuel pressure in your lines,
I would hook up a metal pressure gauge to the hose the cold start
injector uses . I used a gauge I bought at a hardware store or
a industrial surplus store for about 5 bucks and added a hose 
nipple from and autoparts store hooked up the gauge (0 to 60 lbs
range) to the Cold start injector hose and found I had no pressure,
I found that one of my injectors was stuck open and made the pressure 
go down in seconds, I found this when I had both set of injectors in jars
and place the key in the 'on' position and off position several times.

The procedure above will only work if you have a "C" brain on all others
you must crank engine.


Lets say all of this is good then you may have a wiring problem, check 
the wiring , especially the head temp sensor connection , it is very
fragile,
check out the Pressure sensor connections.

Make sure your fuel pressure is adjusted to 28 lbs. 

Most likely , you may have a loose wire so check the schematic diagrams for
the 
system in the Bently VW manual. 


Maybe somone from the list can help you ? Where are you located ?

LEON MARTINEZ

SAN DIEGO AND TIJUANA




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