Slow To Start - Fuel Pump Priming Issue?

[Phil H 16]

I have done and search and found some info, but nothing conclusive.

My J reg 1.9 takes an eternity to start when cold, hot is acceptable. The tacho needle is bumping up and down and coil, plugs, leads, distributor cap and rotor arm are new. Now I believe the fuel pump is the issue, as it has pumped fuel for 169,000 miles. The engine runs fine otherwise and appears to have good compression, or at least doesn't smoke! It did cut out when I had beed gunning it, but soon started again, like as if the fuel had been used up.

Secondly, I don't hear the fuel pump priming the system like all other GTIs I've owned, so wonder if this is contributing. What controls the burst of power to the fuel pump before the engine starts...is it an ECU command or something related to the tachymetric relay? Surely can't be the temp sensor as cars runs pretty well?

Thirdly, my fuel pump has a connector directly on it, unlike all others I've seen that have a short amount of wiring then a connector, so pressume I can modify the wiring accordingly.

 

Any suggestions?

[m@ttc 30]

the tacy relay gets a signal from the ignition switch when you first turn the key this clolses some contacts and puts a supply to the feul pump for a short time, you should here it prime every time. Check you have 12v at the pump as soon as you switch the igition on, this signal is only short as the signal from the coil is then used to close the relay when the engine is running.

[Phil H 16]

This was a simple fix in the end. My car does prime the system on the first turn of the key, but not on consecutive cranking, only when the engine fires will it prime again.

Anyway, disconnected the ecu temp sensor and the car started instantly, but of course wouldn't run smoothly, so popped to GSF and got a new temp sensor, for £10.70, plus the VAT and job done, starts on the button.