I'm at 143k from the factory. Car's fitted with D585's with a dwell remap and was bought with elderly compression 3 years ago....

But it's only lately started to show a peculiar starting issue that I haven't seen anywhere else.

It starts hot. It starts cold.

But leave it an hour, until the temperature needle drops of the gauge - and it sometimes struggles, or even outright fails to catch.

Anytime it's had a problem, the ambient air temperature sensor in the dash is reading above 27 degrees - and usually about 10 or 15 degrees hotter than actual air.

'm pretty convinced the issue is caused by the sensor somehow causing it to tune for a hotter air temperature than really exists and pushiung a worn engine from the 'Starts happily' to 'Nope, Nope, Maybe, Fine I'll run'......

Has anyone ever noticed this starting ppeculiarity before?

 

The sensor on the dash foe ambient temp and the intake temp the motor uses are different sensors.

If it is hot out it is easy for the ambient temp to heat soak from the rad and A/C condenser.

 

I had a feeling that was the case. It might be indicating some sort of heatsoak affecting the car's own intake air temperature sensor...

It happens rare enough that it's impossible to replicate intentionally, but consistent enough that it's noticeable.

Just checking to see if it's one of thoise things, or something unique

 

The IAT sensor is part of the MAF sensor assembly. If you scope the AIT''s you will see if they make sense pretty fast. They will heat soak at rest and drop as you drive. Should be about 5 degrees above ambient cruising on the hwy ....