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Re: [T3] More FI Madness

On 18 Dec 2003 at 6:38, Tony Rongey wrote:

> I took a break from the engine to rebuild the AT.  Now I'm back to the FI,
> and I've got 3 of 4 cylinders working.  #1 still isn't contributing though. 
> With a test light I can see #1 getting injection signals.  I've verified that
> it's getting spark.  I've rechecked the valve lash all around.  The injector
> is new. 

If you're using a normal mechanic's test light to stick in the rear of the 
connector, that's fine, but if you're using one of those little expensive Noid 
lights that are sold for this purpose, then you should't do this. The Noid 
lights were made for the later L-Jetronic FI and have pins which are too thick. 
They will deform the socket pins in your injector connector so that you won't 
get good connections any more.

> If I disconnect the injector the engine seems to smooth out a little.  If I
> disconnect the injector and ground the hot wire from the ECU the engine gains
> about 100 rpm.  What is this telling me?  I'm stumped. 

Not sure what this means, but I'm pretty sure this is not a good thing to do. 
It seems likely to me that this would damage the brain. I just don't know 
what's in there that is limiting the current. If you draw too much you'll blow 
out the drive transistor for #1 & 4 cylinder.

This MIGHT mean that you're getting less pulse to #4 (they get driven by the 
same transistor) and that this is making the car run better. This would be a 
sign that the car is running rich. On that assumption, check the following:

Check the battery voltage with the engine warmed up and running at medium RPM. 
It should be 14.1-14.4 V. If it is less than 13.5V replace the voltage 
regulator with a Bosch 30-019. Low system voltage makes the FI run rich.

Check the fuel pressure. On a 69 it should be about 29 psi.

Jim Adney
Madison, WI 53711-3054

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