Slow startup issue only when cold (video)

Hi, I’ve been having this issue lately I think it might be getting worse but still, car starts up every time just cranks longer than it should. I feel like it should crank once and start but it takes about 2/3 cranks sometimes 4 and then it starts.
This only happens when car is completely cold ie I parked it overnight and next day it would do this. Now this doesn’t happen every time. Sometimes it can start normally but only if car is completely cold. I can drive it and come back to it and starts up on first crank.
A bit of background on the car
I did the valve cover gaskets, and spark plugs and cleaned the injectors with throttle cleaner and a bath in the ultrasonic cleaner. One thing I didn’t have any dielectric grease so I didn’t put it on the ignition coils.
Anyways here’s the video

Get your battery tested.

Check your ground cables

The longer crank for cold start is more for emissions, if there is even a single misfire it can fail an emissions test, so the computers will verify everything before delivering fuel. So sometimes you see long crank times like this. Your video sounds pretty normal to me.

Had same issue. If it's only the cold start could be a fueling issue - losing pressure overnight. This would either be a leaky injector, LPF sensor bad, or fuel pressure regulator. Those are the only 3 things that would cause issues with fuel system losing pressure. Next time you start the car, cycle the fuel pump 4 times (without pressing brake, press the start button and you'll hear it prime, turn off and repeat). If it fires up right away - you have a fueling issue. If it doesn't, it could be battery related.

acarr6 wrote

Had same issue. If it's only the cold start could be a fueling issue - losing pressure overnight. This would either be a leaky injector, LPF sensor bad, or fuel pressure regulator. Those are the only 3 things that would cause issues with fuel system losing pressure. Next time you start the car, cycle the fuel pump 4 times (without pressing brake, press the start button and you'll hear it prime, turn off and repeat). If it fires up right away - you have a fueling issue. If it doesn't, it could be battery related.

I primed it 4 times as you said and it fired up right away here’s the vid.
I decided to take it upon myself and took off the plenum and inspected the fuel injectors. I didn’t see any leaks around them so I opened up the throttle bodies and I found all cylinders had either oil or maybe fuel on the valves. I’m not sure if this would point at leaky injectors. Any thoughts?


Also I found one hose that goes under the plenum was not plugged in and one ground on driver side that sits on the valve cover was loose and not tight.

Mine does this now all of the sudden. Exact same scenario as you explained.

I'll be following to see what solutions we can find.

Rino924 wrote

Mine does this now all of the sudden. Exact same scenario as you explained.

I'll be following to see what solutions we can find.

Tbh I think it’s leaky injectors. I should not have any liquid on top of my valves and only injectors make sense. They’re most likely originals as well.
I’ve seen a lot of people score their s65 or blown them up completely due to faulty injectors. I think it’s like the next thing compared to rod bearings.
I’ve ordered a set and should have them by next week. Ill post updates once they’re in and I’ve tried them for a few days

asma123 wrote

Rino924 wrote

Mine does this now all of the sudden. Exact same scenario as you explained.

I'll be following to see what solutions we can find.

Tbh I think it’s leaky injectors. I should not have any liquid on top of my valves and only injectors make sense. They’re most likely originals as well.
I’ve seen a lot of people score their s65 or blown them up completely due to faulty injectors. I think it’s like the next thing compared to rod bearings.
I’ve ordered a set and should have them by next week. Ill post updates once they’re in and I’ve tried them for a few days

You could also remove the injectors and have them tested.

asma123 wrote

Rino924 wrote

Mine does this now all of the sudden. Exact same scenario as you explained.

I'll be following to see what solutions we can find.

Tbh I think it’s leaky injectors. I should not have any liquid on top of my valves and only injectors make sense. They’re most likely originals as well.
I’ve seen a lot of people score their s65 or blown them up completely due to faulty injectors. I think it’s like the next thing compared to rod bearings.
I’ve ordered a set and should have them by next week. Ill post updates once they’re in and I’ve tried them for a few days

One of the S85s well documented flaws is sticking injectors. Makes sense it would trickle down to the S65.

This is an old issue on this forum. The low fuel pressure sensor near the firewall on the driver's side is usually one of the main culprits for causing the issue. Cheap and easy to replace too. There's not a lot of difference IMO between the two videos the OP posted but it may get worse.

https://www.m3post.com/forums/showthread.php?t=880179

asma123 wrote

I decided to take it upon myself and took off the plenum and inspected the fuel injectors. I didn’t see any leaks around them so I opened up the throttle bodies and I found all cylinders had either oil or maybe fuel on the valves. I’m not sure if this would point at leaky injectors. Any thoughts?

Those valves and valve stems look mint IMO.. Darn clean indeed. Not a problem IMO..
.

DrFerry wrote

This is an old issue on this forum. The low fuel pressure sensor near the firewall on the driver's side is usually one of the main culprits for causing the issue. Cheap and easy to replace too. There's not a lot of difference IMO between the two videos the OP posted but it may get worse.

https://www.m3post.com/forums/showthread.php?t=880179

Pretty rare for that to be the case and not throw any codes though..

Problem solved. I changed the injectors and cleaned the ICV. Started up almost instantly. Plus performance feels like it’s improved quite a bit. Maybe it’s the placebo effect lol

Also experiencing the same thing. Had the fuel injectors and low fuel pressure sensor both replaced. Fuel pressure regulator was also mentioned in this thread but I can't find anything regarding it. Does anyone have a part number or suggestions on what else it could be?