My Octavia 2 1.9 Tdi has suddenly become difficult to start when hot. The longer it's been switched off, the more cranking it takes. The battery seems lively enough to turn the car over quite briskly, but it takes a good few turns before it finally fires. The dealer says there are no codes showing and I can't see any fuel line leaks. Any ideas, guys??

Edited 28 May, 201016 yr by billperk

Difficult hot starting on a diesel usually points to problems with the starter, or fuel vapourisation in the injectors (rare this second one).

So I'd look for a proper auto electrician near you.

Difficult hot starting on a diesel usually points to problems with the starter, or fuel vapourisation in the injectors (rare this second one).

So I'd look for a proper auto electrician near you.

Thanks for the quick response. Starter was replaced quite recently, but will investigate.

Did the problem first appearing happen to coincide with the starter bring replaced? I've seen a few people mention the battery being slightly down on power being part of the cause though, so possibly check battery voltage. If anyone can suggest what the car should do differently on a hot start as opposed to a cold start that should suggest possible causes.

Did the problem first appearing happen to coincide with the starter bring replaced? I've seen a few people mention the battery being slightly down on power being part of the cause though, so possibly check battery voltage. If anyone can suggest what the car should do differently on a hot start as opposed to a cold start that should suggest possible causes.

Thanks for reply. Starter turns over fine, though admittedly battery isn't quite 100%. Was hoping for something obvious, like a fuel leak allowing air in, but can't see any. some people have suspected coolant temp sensor. Will see what the dealer comes up with on Tuesday and report back.

Edited 29 May, 201016 yr by billperk

I've the same problem, if i give the engine one or two cranks to start with. Then stop, and try again, it usually starts straight away the second time.

Edited 29 May, 201016 yr by Browny_37

My 1.9 was exactly the same. I just lived with it. Never got any worse.

Battery voltage will recover slightly when standing and not being used, so first thing in the morning there will be a slightly higher voltage there, which is probably just over the threshold for the ECU thinking there's nothing wrong, so the car will start instantly when cold. Once it's been used to start up, voltage will drop again to a point where the ECU senses a problem.

Despite mine being so sluggish to start when hot, it never once did fail to start -- eventually. It didn't sound like the battery was flat, it just sounded like the car wasn't firing. Once it did fire, there was no lumpiness or hesitation, everything was as normal. Local dealer wanted to try a starter motor first -- it would have been an expensive mistake.

I changed the battery because it was the original one on the car at a 54 plate.

Mike

Problem seems to have sorted itself somehow, perhaps because of the better weather, but I think from what you're saying that a new battery would be a good idea anyway. thanks for all the recent advice, guys. It's much appreciated.

Bill P