2012 jsw long crank lots of grey smoke first start of day.

[norel]

My 2012 cjaa has been progressively starting harder first start of day. I've only had it since January It started instantly in single digit Temps. In April it started hard maybe 10% of mornings, now it's 100%. I get lots of Greyish smoke on first start, extended cranking. It runs fine, starts easy until it sits overnight. Car is deleted, tuned I have no idea whose tune. Only code ever is implausable fuel pressure sensor. Fuel filter and auxiliary pump replaced recently. Good pressure instantly per vcds while cranking,. Fuel pressure instantly drops to 0 when not running. I noticed when I changed out auxiliary pump that Fuel siphoned back into filter like there was no check valve anywhere. Lift pump makes noise, I haven't checked output. Both pumps run with output test, but neither come on with key on accessory position. I thought rail was supposed hold some pressure when off? I did notice that my 4,5,6th gear 1700rpm-2k stumble went away when I replaced auxiliary pump, which makes me wonder if lift pump was starving it? Is there some way to rule out leaky injector before I replace lift pump, fuel pressure regulator, etc?

 

[Tuheeden]

Do you have VCDS? That would really help and is with the purchase to save you from buying parts that are not broke!
No the rail does not hold any pressure when off and it sounds like air is getting into the line or poor fuel pressure to the HPFP.

 

[norel]

I have vccds. I have plenty of pressure (pressurized air with fuel?) I suspect air as well. The car does the same thing if If I cycle both pumps on with output test for 5 minutes, so if it's air, it's downstream of both electric pumps? I have double the rail pressure needed for starting instantly, per vcds. Is there a check valve in the system? This is my first cr car and I don't really know what's normal for them.

 

[lemoncurd]

Both pumps run with output test, but neither come on with key on accessory position

normal.

grey or white smoke would indicate excess fuel that is unburnt.

this almost sounds like a hotstart issue?
do you have the same problem once the car is at operating temperature and you go to turn it back on, say after getting stuff in a store?

 

[crediblesole]

Can I Jump in on this thread, I have a 2014 CJAA that has developed a hard start issue when left sitting over night?

Fuel pressures seem good across the board. Once it starts it doesn't seem to have any performance issues, also once it does start that first time it will be fine all day long. I'm at the point where I could use some help I feel like a dog chasing its tail at this point. I did have the fuel lines off at the filter 6 weeks ago to change out some clamps at the filter but the problem started before that.

 

[Porch]

My JSW was doing that when I was working in vail, CO- long crank on first start, puff of white smoke, then fine all day after that. When I went down the hill, it never happened again. My car was deleted, and its hpfp had blown up and then been replaced, along with the entire fuel system, long before this weird, ultimately temporary issue started. It's now on to its new owner and is still running great.

Try running diesel kleen in the fuel, can't hurt.

 

[calimustang]

Try running diesel kleen in the fuel, can't hurt.

yep good tip right there!