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Re: [T3] engine cuts out

On 22 Aug 2001, at 20:50, Peter Legault wrote:

> My wives 73 square has come up with a hiccup. I was driving it the
> other day and it just stalls momentarily as if it has lost fuel
> supply. I have checked most connections and hot wired the fuel pump to
> the ignition (to bypass the relay circuit), but the problem is still
> there. I have noticed that the pump is whirring somewhat (you can
> actually hear it while driving) louder than usual. It also seems to
> vary speed somewhat while idling maybe +- 50-75 rpm and one can hear
> the pump change rpm in unison with the engine rpm. I noticed this when
> I grabbed a hold of the pump with engine running to check the
> electrical connector for bad connection. It seems to whir up and down
> a bit and the engine follows it. Could this be a sign of a pending
> pump failure?

If the FI pump stops completely, the engine will slowly loose power 
as the fuel pressure drops. This will take a noticable few seconds. 
>From your description, I gather that your problem is a rather 
sudden switching off and back on of the engine; this is a sure sign 
that it is NOT a fuel pump problem.  

The pump speed variation is simply the normal response to 
changing system voltage at idle. At speed the voltage is regulated 
(stable) and the pump speed is too. Both are also higher.  

Instead it is an electrical problem, either FI or ignition. These can 
be hard to track down simply because it is hard to catch the car in 
the failed state so you can start eliminating possibilities. If you 
have such an opportunity, start by checking for spark using a 
timing light just to verify that there is something going to the plugs.  

When this happens, how long does it last? Do you hear any of the 
FI relays clicking when this happens?  

Things to check for would be the usual ignition things: dwell & 
timing, and all the FI wiring, particularly the grounds at the center 
of the engine. If you care to take the dist out you could clean the FI 
points that are mounted in the side of the dist. DON'T file them, 
just clean them with a clean piece of paper without leaving any 
paper fibers caught in them.  

Let us know what you find.  

Jim Adney
Madison, WI 53711-3054

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