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Re: [T3] Total FI death (was FI fuel pump relay)

> On 7 Jul 2005, I wrote:
> > Its going to take a while to check over all the connections so I'm
> > not even going to start asking questions yet ...
> Jim replied:
>  Things to consider:
> Do you hear the 2 relay clicks when you get in the car and
> turn the key ON?

Yes, except ... (*) (see below)

> Do you hear the fuel pump run between those 2 clicks?

Yes, except ... (*) (see below)

> With the key ON, go to the engine compartment and push the
> throttle open. Do you hear a series of clicks as the throttle
> goes open?

That was fun. Never tried it before. 20 little clicks from both
banks of injectors, and all in the right order :-).
That's a very good test of most of the FI system in 1 go.

> Get a friend to crank the engine with the starter while you
> check the dwell.

Prior to the fault it ran fine, so highly unlikely to be
ignition timing.

> Remove the 3-pin connector from the side of the dizzy and put
> an Ohmmeter between the center pin and one of the side pins on
> the dizzy. Get a friend to turn the engine over with the
> starter. Do you see the needle bouncing between zero and
> infinity? Check both sides.

Yep. Even works when manually turning the engine over using the
gen pully (130K miles means poor compression, so I don't even
need a spanner on the nut!).

> The correct answer to each question should be yes. Run down
> this list and stop as soon as you run into a "no."

Oh dear. No "No"s ...

So, I made a test cable with LEDs across all the relays and
a multimeter wired in to see the FI supply voltage.

While I was wiring it in, sitting on tunnel in the back, the
fault came back: FI relay clicked, but no pump. Then the FI
relay went off again. I had nudged the battery terminal.

Because the car stands a lot, I keep taking the battery out
to charge it. And I don't tighten the terminal clamps as its
a real chore, and they make a nice tight contact as they are.
But ... the FI feed comes off the +ve terminal clamp bolt, so
this was loose! And it was old & dirty. So it was all down to
poor supply. Even when the ECU tries to turn on the pump, if
the switching voltage isn't high enough, the relay won't

Haven't driven it yet, but I'm 99% certain this is the cause.

This is very embarassing, as its all down to "DCO" : dreaded
current owner. Can't even blame it on the DPO. Sorry !

Matt. UK.
'73 1600e FB.

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