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Topic: Mystery starting issue 1.8 GTi PB- help! (Read 9 times) previous topic - next topic

Mystery starting issue 1.8 GTi PB- help!

Looking for help with an ongoing issue.
My 8v GTI digifant has an ongoing starting issue. It takes a good 5 seconds turning the engine over before it fires and then it runs really lumpy. After a little throttle for a few seconds it clears and runs great. Car pulls really well when driving. No smoke etc and gets good MPG when I’m cruising along.
Car has had a full diagnostic and tune. Plugs, rotor, cap, leads and coil all good. Recent new idle valve,  both fuel pumps have been replaced and prime as you would expect.
Battery has full charge and volt meter is showing good volts when running. Throttle body switches are working and lots of the connectors have been cleaned. No vacuum leaks. Blue temp sensor tested.
Injectors have been tested and are in great condition.
It occasionally starts fine, usually in the morning. When it’s been to the garage to check for known faults, with no solution found, it starts fine for a couple of days then the problem returns. If I restart the engine within a couple of minutes of turning it off it works fine.
Engine was rebuilt last year by previous owner and has run fine until now.
Good oil pressure on start up. In the recent hot weather with oil temp at 130c oil pressure at idle can drop to an indicated .6 bar but no oil pressure warnings on dash.
My local specialist who knows these engines very well is now expecting an electrical issue.
But I would love some input from other MK2 owners.  Thanks in advance for any suggestions
 

Re: Mystery starting issue 1.8 GTi PB- help!

Reply #1 –
Hi I am currently  experiencing similar issues. I can start the car from cold fires straight away and runs perfectly. When the car warms up   I have the same issue as you. I think the fault lies with the blue temperature sender I have ordered a replacement and am awaiting its arrival so can not say if that is the issue yet. Out of interest I ordered a hella replacement as I understand other makes are thought to be unreliable.