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Re: [T3] wont start when hot

On 6 Jun 2002, at 6:35, Drake wrote:

> According to my wife, who is the driver...it always runs perfectly fine it
> just wont start when its hot. 

Is that to say that if you park it while hot, but let it sit until it cools down that 
it will then start just fine? If so, when you get in your car and turn the key ON 
do you hear 2 distinct clicks, separated by about a 1 second pause? The 
fuel pump should run during this second and then turn off. Is this what you 
hear? You may need a friend to listen under the front of the car for the pump 

> I was going to unplug the connection to the cold start injector next, I seem to
> remember sometime back that this could cause flooding. 

This is possible, but ONLY if there are other things miswired. Try this, AND 
do the tests above.

> Two things come to mind
> as to whats behind this issue. Vapor lock, or flooding. I would think that 30
> psi of fuel would be able to break any vapor lock, so that leaves flooding.

Vapor lock only occurs on the INLET side of the pump, when the fuel is 
warm enough that the vapor pressure of the gas exceeds the vacuum 
necessary to pull gas in the pump inlet. This is virtually impossible on a FI 
engine since the pump is under the tank, and the engine heat is elsewhere.

> Flooding with fuel injection also seems like an improbability, but I seem to
> recall someone suggesting that the cold start injector can cause flooding. I do
> not remember the circumstances though that would cause the flooding.

If unplugging the CSV cures the problem, this tells us where the problem 
must be. If the CSV is wired properly and the temp switch is okay, the CSV 
will not fire in warm weather. I have never seen a bad temp switch, but I have 
seen several cars with miswired CSV circuits. There is one miswiring that is 
particularly common on 72s, and this is even specifically mentioned in the 
Bentley manual. If you only hear one relay click when you turn the key ON, 
and the fuel pump just runs continuously (engine not started), then this is an 
easy fix.

Listen for the 2 relay clicks and tell us what you hear. Unplug the CSV and 
see if that makes any difference.

Jim Adney
Madison, WI 53711-3054

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