[T3] FI Problem

[Jim Adney]

On 28 Aug 2012 at 0:00, Robert Rogers wrote:

> I´m working on a 1978 Type 1 FI system.  I need your expertise.  

I've worked on exactly one Type 1 FI system. Not exactly experienced 
at this. I used the Type 1 Bentley manual troubleshooting 
instructions.

> If I spray starting fluid into the air intake, the car will start and
> run until the fluid is depleted. 
> 
> Fuel is getting to the injectors.  However, when the engine is
> cranked, there is no spray from the injectors.  The injectors are new.

Have you checked the fuel pressure? It's hard on those cars: There's 
no test port. I think I ended up bending a pipe above the alternator 
to get access to measure pressure. Once you get there, the pressure 
is different (higher) than Type 3s.

> How do I check to determine if the injector wires are providing a
> signal to open the injectors-check for voltage at the end of the
> injector wires while the engine is cranked?  

Yes, but the signal is brief, so it might not show up on most 
voltmeters. There are things called "Noid Lights" which you can buy 
to plug in instead of injectors. They will flash when they get 
voltage. You can buy them on ebay, often in sets of 4.

NEVER, NEVER, NEVER plug these into D-Jet injector connectors! They 
will damage the connector on your D-Jetronic harness. In spite of 
what the seller may say, they are strictly for L-Jetronic style 
systems.

However, if the injectors are new and the pressure is there, then the 
Noid Lights are kind of pointless, because you already know that  
there's no signal coming to the injectors.

Okay, I just did a search on ebay, and found that things have changed 
since the last time I looked at these. It appears that there are now 
MANY styles of Noid Lights, to mate with MANY different kinds of 
injector connectors. They tend to come in sets with many different 
versions. I doubt if any of them work with D-Jet, and I can't tell 
which ones might work with early Bosch L-Jet. If you go this route, 
I'd check out a FLAPS and see what they have.

I recommend that you work your way thru the Bentley instructions, and 
that's agonizing. There's no dedicated tester that I know of, so you 
have to use a voltmeter, just like they describe.

Good luck,


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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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