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Matt, Engineer
Category: Car
Satisfied Customers: 21853
Experience:  Honors degree in Mechanical Engineering, worked 8 years as a Formula 1 engine engineer.
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A 2000 seat ibiza 1.4 lt 16 valve gas ,it..intermittant..mechanics

Customer Question

i have a 2000 seat ibiza 1.4 lt 16 valve gas ,it has an intermittant ingition cut out that is very sporatic and after 5 min it will restart,mechanics have not been able to find the problem after numerous attempts to repair. can you help please.
Submitted: 7 years ago.
Category: Car
Expert:  Matt replied 7 years ago.


I'd start by checking the resistance of the spark plug leads ( 13-15Kohm / metre) and replace if any doubt or high resistance - Also replace the spark plugs if any of them fail this checklist:

Then check all the connections to the engine sensors one at a time, remove each one and examine for signs of corrosion or damage and a squirt of contact cleaner ( not WD40) will also help.

This could be an airleak after the airflow meter, any air dragged in here isn't 'seen' by the ECU and so not compensated for and leans the engine out causing rough running.

Check the hose clips for tightness and inspect the trunking for any cracks or splits and also all the vacuum system, the small bore pipes and fittings for cracks and missing parts.

The best way to locate a leak is to have the engine running and warm and then spray lighter gas around each joint in turn. If the engine rev's up you've found your leak.

Work your way through each possible joint one at a time and you should find it. I use a slightly flattened piece of brake pipe and some rubber hose from the can of lighter gas to provide a spraying 'wand' and allow a direct blast of gas into each area, especially those difficult to reach with large implements.

Air leaks are very temperature dependent as gaps can open or close up as things expand with heat, so they can be effected by the weather and engine temperature.

This leads them to be quite intermittent in the case of mild leaks


It’s also worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a poorly pump will all result in insufficient fuel being delivered to the engine

Also check the ECU power supply (fuse and relay) and those for the fuel pump supply and also the connections to the crankshaft speed sensor.


Customer: replied 7 years ago.

hi matt

these answers are all things that are simple repairs and should have been looked at ,this problem does not have a time line for stalling the engine it could be months or days and will so far always restart after 5 min or so ,car runs good .

Expert:  Matt replied 7 years ago.

The problem is with intermittent faults is they rarely happen in the workshop so you have to work through a lot of the simple stuff to ensure its all connected and working properly.

I agree the garage should have worked its way through these items but they may not have done.

Usually the real culprits for this sort of thing is a bad electrical connection for the ECU or coil or fuel pump so start with the relays and fuses 1st and also check the connector plugs.