So if I try to start my car in the shade/garage the thing fires right up and idles just under 1,000 RPM. However, when I have the car parked in a heated area, i.e. sunshine, and start it, it'll fire up but then dies unless I pump the gas.

Is this an area of anything to be concerned with? Or is it just that the petrol is hot and thus less dense so the engine can't stay firing?

 

Sounds like a possible vapor lock issue? Someone more knowledgable will chime in, but I think it has to do with a charcoal canister filter somewhere near the fuel tank. Sorry I couldn't be more helpful.

 

Sounds like a weak fuel pump. It is 23 years old, and OK, it has seen little work by comparison.

The 1990 pump is an external in the boot/trunk, alongside the spare wheel, and relatively easy to change, and not real expensive.

My advice is to remove EVERYTHING from the boot, as fuel spillage will occur, and any carpet, etc that gets fuel on it will stink forever. There is simple no way of removing that stink.

Your market has a lot of emission items we did not see, and any of these could be having an age hissy by now, so people in your area will assist when they catch up with this.

 

How hot "heated area"? A pleasant 75ºF or a god-awful 110ºF? And, how long parked? How long had the engine been running?

I think the fuel would have to reach about 150º-160ºF before vapor lock would be a consideration, so you'd need a very hot day and/or quite a bit of engine bay heat.

(I mention 150º-160ºF only because I *think* that's the trigger temp for the fuel temp switch....which is supposed to eliminate the chance of vapor lock)

Try leaving the hood open so engine bay heat can easily escape. If the problem goes away, it does begin to sound like a vapor lock issue....which is a bit unusual, it seems.

A weak fuel pump, as Grant mentioned, can cause or contribute to this symptom. More common than actual vapor lock.

Cheers
DD

 

Heat: 90 degrees F
Engine Running: 20-30 minutes

I thought that the fuel pump had been replaced but I'm not 100%. I'll dig through the records tonight and see if it has.

 

Well, next time this happens dribble cold water over the fuel rail or wrap them in rags soaked with cold water....or some similar effort. If the car then starts easily, you know that you have a vapor lock problem

Cheers
DD

 

I have been reading up and learned that the A/C hipressure hose has a heat exchanger to cool the fuel. Look at the HP A/C hose as it leaves the compressor and before entering the cowl area..you will see the heat exchanger. Also there is a hot starting "circuit" incorporated into the fuel system that raises the fuel pressure temporarily. I haven't fully learned about it but it does exist. When I have time I will research more...going on a motorcycle trip.

 

Right! Plus, thus the fuel temp switch, as mentioned above

There were a couple variations on the fuel temp switch. Earlier cars had vacuum-only temp switch, which vented vacuum to the fuel pressure regulator so as to increase fuel pressure. Later cars had an electro/vacuum switch....not sure how that worked, exactly.

As for the cooler, starting in '89 convertibles had a unique climate control circuit which kept the a/c compressor engaged even with the mode switch set to "off". This allowed fuel cooling at all times, under the presumption that drivers would have the top down in hot weather rather than use the climate control.

Of course, if the a/c system....at least the refrigeration portion of it... isn't working you won't get any fuel cooling not matter what.

Cheers
DD