Starting problem ST24

[junglie]

Hi everybody,

Mondeo ST24 Saloon (1997) - Car has been absolutely fine but struggled to start today after standing for a week. Have left it for months and it has always been just fine. Today it fired straight away then stopped after half a second. It then turned over although it sounded slightly laboured (battery voltage is fine) for perhaps 20 secs before running, accompanied by some unburnt petrol fumes. It did not idle at 1200rpm but went straight to 750rpm and was a little rough until warmed up. After that is is business as usual. There was hardly any fuel in the tank which leads me to believe that either there was some backflow from the injectors or the cold start relay is not working (have a similar set up on my Essex V6). It was serviced 10k ago. Any thoughts welcomed. Looking forward to being back up to 100% from the trusty mondeo!

Dan

[jackst]

hi ya it could be your leads? a friends got a st24 and he had the same problem. i'll see if i can find out for you.

[Zad]

I agree, as it has fuel and compression, the logical conclusion is the spark. It is probably worth WD40-ing the coil packs too. Make sure the coil pack connectors are all ok and haven't got any moisture that has condensed onto them. I think there was a night time frost a few days ago, so there would be moisture around.

I hope the neat petrol didn't damage the catalysts.

[ZZR]

junglie said:

Hi everybody,

There was hardly any fuel in the tank
cold start relay is not working (have a similar set up on my Essex V6).
Dan

Hi,

It's never a good idea to run a modern injected vehicle low on fuel, you'll pick up all the sediment and moisture from the tank and the swirl pot won't operate correctly, meaning you won't maintain sufficient fuel pressure.

Your Mondeo doesn't have a cold start relay, it's all controlled by the ECU and it will try and adjust the fuel settings and idle speed to maintain the correct emissions from cold, these engines can be a bit temporamental if they are not run for a while.

[Zad]

ZZR said:

It's never a good idea to run a modern injected vehicle low on fuel, you'll pick up all the sediment and moisture from the tank and the swirl pot won't operate correctly, meaning you won't maintain sufficient fuel pressure.

A common misconception. Sediment and moisture drop to the bottom of the tank (oil/petrol floats on water remember). This means that it gets drawn up the fuel pickup (which is of course at the lowest point of the tank) almost as soon as it gets into the tank. If water got into the tank in a week then there must be a problem with the filler (the tank is plastic so it hasn't rusted).

[ZZR]

Zad said:

ZZR said:

It's never a good idea to run a modern injected vehicle low on fuel, you'll pick up all the sediment and moisture from the tank and the swirl pot won't operate correctly, meaning you won't maintain sufficient fuel pressure.

A common misconception. Sediment and moisture drop to the bottom of the tank (oil/petrol floats on water remember). This means that it gets drawn up the fuel pickup (which is of course at the lowest point of the tank) almost as soon as it gets into the tank. If water got into the tank in a week then there must be a problem with the filler (the tank is plastic so it hasn't rusted).

And the swirl pot swirls the fuel to prevent the fuel from overheating and so lifts sediment and moisture, anyway, still not good to run the tank low.