Cant find same issue searching so ill just ask.
i am worried about my hot starts once my baby has heat soaked. It idle around 500-700 rpm and has black smoke puffing out her rear. Once i give her a little rev she settles down to normal 950rpm. Just worried about the black smoke. Compression is 110-115 on all faces. I do have high water temp of 110°c on start up but drops to 80-85°c once driving (home made v mount) and air temps are 60-70°c on start but crash once moving to 10°c above outside temp.
any thoughts please

 

Stock ECU or PowerFC?

Could just be dirty fuel injectors or way old spark plugs.

Dale

 

Hey dale.
have tuned pfc at 300whp. Have just replaced sparks plugs with 7s and 9s and new set of ngk power cables. Injector duty is at 87% and thought if it was them then it should show its self with duty cycle or performance?
On a side note: thanks for all your knowledge you have shared on this club. You have helped me alot with what i have done to my baby.
cheers
mickey

 

Could also be something in the PowerFC map, I remember my PFC would idle a bit weird with my stock intercooler when it was big time heat soaked. I believe there is a setting to retard ignition timing when intake air temps are high. I think you need to use a Datalogit to edit those settings.

Dale

 

Will have a look into that when she is back on dyno hopefully next week once the hks twins unit gets here. Was also looking at replacing AIT sensor, as thats my last idea to solve the problem but had not thought of the pfc! Will report back once the retune.
cheers mate

 

I think you can check the IAT status on your commander’s sensor screen. If it’s shaded it’s faulty.
And at least it’s black smoke. IMO, that’s way better than blue or white.

 

Didnt know that, will have a look later today. I agree but i would rather no smoke at all and she never does expect with the issue thats just popped up.

 

PFC says the sensor is reading. Just installing hks twins and bonez hi-flo this weekend. Will be going for a retune next week and will report back.
Cheers

 

My car has done this a few times. I wasn't paying specific attention to the water temp, but it was def in the mid to high 90's. The last time it did this, it cleared right up as the temp started to drop after the water started to circulate, while watching the controller. My tuner wants to check the higher water temp cells in the PFC map to see how they are set up. Will prob have to wait until spring/summer.

 

This wasn't specifically mentioned. So the black smoke could be a leaky fuel injector that loads up the LIM with fuel during a hot soak, causing the black smoke at startup. After a longer downtime, the excess fuel would likely evaporate and not cause black smoke.

 

Could it be a very small leak? Ive never smelt fuel under the hood and it get left open everytime i get home. If it is i hope it will show its face on the weekend when she gets a retune. I will be taking for about a 5000 km trip over jan so hopefully all the little issues wont become big ones

 

It could be leaking only into the manifold, and not be apparent externally. While the fuel is still under pressure, injectors can leak at the interface of the pintle and its seat (internal to the manifold) due to wear or deposits. If this is happening, and you have a fuel pressure gauge, you will see fuel pressure gradually drop off. It can also drop for other reasons, but that is one of them.