Hard to start when hot

[taximan480]

Hi guys
I need really your help and advice again
C530KGH is fighting her move to the emerald isle all the way (only 4 weeks late ) and she is really tormenting poor old Charlie. She starts on the button when cold but as soon as she warms up she is really difficult to start, any one had this problem and if so what's the solution

Bob

[mrzigazaga]

Hi Bob


Never had this issue...could be related to temperature sensor or a broken wire that is expanding when hot...


Sorry i cannot be of much help...

Ziga

[KKson]

Hi is this a V6 or V8? Had a similar issue with my 350i two months ago. Culprit was ignition amp. Double check the strength of spark when it won't start. When cold I had a big fat spark. When warm it was a feeble excuse of a spark. New amp fitted and now all good.

[taximan480]

Thanks guys
Charlie is looking at the ignition amp as I write
Bob

[adam quantrill]

KKson said:

Hi is this a V6 or V8?

According to "my garage" itr's a Hyundai Sonata! ;^)

[350zwelgje]

Coil is worth a look as well, as you could have the same symptoms.
A possible test is to cool the coil when not hot starting, if starting you have your answer.

Rob

[JamesMK]

I've had that with a starter motor that wouldn't turn over when hot - cabling wasn't heavy enough, esp the earth. Once I got heavier duty cabling to it the starter was transformed hot or cold.

[Tony Trans Am]

Was fuel accumulator on my V6

[taximan480]

C530kgh is the 350I V8

[mrzigazaga]

KKson said:

Had a similar issue with my 350i two months ago. Culprit was ignition amp. Double check the strength of spark when it won't start. When cold I had a big fat spark. When warm it was a feeble excuse of a spark. New amp fitted and now all good.

If replacing the amp then dont forget to use the heat-soak paste when mounting the amp...

[adam quantrill]

Ahh the V8 - I should be able to help then.

Did you say it's on the Emerald ECU or do you mean it's been exported to Ireland???

In any case yes as mentioned above check the engine temperature sensor (not for the water temp meter but the ECU one) and the Ignition amplifier. The latter can be diagnosed by seeing if there's spark then hot during cranking - plenty of strong spark and it's probably something else.

[KKson]

Yep, in order of suspicion I'd say ignition amp, coil and then temperature sensor.

[taximan480]

Not been exported but it will be if she behaves herself long enough to get to the ferry