43.65PSI if you want to be exact the pressure is higher with a cold key on though 58.01 PSI
I have see it as high as 80PSI in Auto Stop,, which instantly drops to 43.65 psi when the engine starts at 1500rpm
07 Suburban rough idle P0304 code afm delete
- Thread starter smokymtn65
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
I have see it as high as 80PSI in Auto Stop,, which instantly drops to 43.65 psi when the engine starts at 1500rpm
swathdiver
Full Access Member
I do not know, wouldn't think that to be an issue for the Candi not working.
When I first got my Tech-2, my Candi was not recognized either. Turned out to be a defective OBDII adapter. Replaced that and all was well.
OP
OP
smokymtn65
Full Access Member
So, I could write a book about what all has happened since the DOD / AFR delete. Went to a new tuner because of the persistent hot hard start issue. He thought he fixed it but has not. however he found thing in tune that were wrong and fixed them and the truck now idles smooth and runs better. since the hard start issue started right after delete and first tune they thought is was connected. Since then the purge solenoid has been changed,(i know new doesn't mean good) and vent valve has been change neither helped.
Is there a way to test solenoid?
any ideas?
THanks
Is there a way to test solenoid?
any ideas?
THanks
Interesting. I have the BTR Stage 2 (v2) truck cam in my 6.2 since the winter, and it has stalled once and been a little hard to start when hot a couple of times (cranks an extra second or two), but it's very rare. Idle is definitely a little choppy but I like it. Is your stage 2 cam a v2 or a v1 version? I'm wondering if maybe they had some drivability issues with the v1 version that led to the v2. Just thinking out loud. Also, I had Black Bear do my cam tune and they did a great job so I wonder if it's worth having Black Bear do a tune for you. I know it's pricey, but might help solve your issue. You could always revert back if you need to.
The only other thing rolling around in my head is the possibility that the fuel pump is on its way out. When they start to fail, stalling and hard starting, as well as throwing the stabilitrak code are some of the ways that they start talking. How many miles on your rig?
What else have you experienced since your cam swap that might be significant that's not already mentioned in this thread. Anything else I should be on the lookout for? We're fixin' to pull our camper 4500 miles in the next 3 weeks, so it's gonna get a good shakedown.
Have things moved on from the #4 miss to an evap code (P044x)?
OP
OP
smokymtn65
Full Access Member
Your going to force me to write the book huh? LOL
I've had an oil pump failure, trans failure, and head replacement all in between. The oil pump relief decided to stick open.
Trans was unrelated to missfire at idle we fought for a long time (fixed) that kept triggering stabilitrack.
Cam; BTC- 1461218132
reworked heads due to valve issue on 4 which was the miss fire code. but it didn't fix the missfire.
Truck runs good now except for the hard start when hot. I got 17.5 mpg highway without DOD so happy enough.
I can smell gas when it gets parked sometimes
I've had an oil pump failure, trans failure, and head replacement all in between. The oil pump relief decided to stick open.
Trans was unrelated to missfire at idle we fought for a long time (fixed) that kept triggering stabilitrack.
Cam; BTC- 1461218132
reworked heads due to valve issue on 4 which was the miss fire code. but it didn't fix the missfire.
Truck runs good now except for the hard start when hot. I got 17.5 mpg highway without DOD so happy enough.
I can smell gas when it gets parked sometimes
OP
OP
smokymtn65
Full Access Member
no codes now at all just extended crank when hot
OP
OP
smokymtn65
Full Access Member
@Geotrash She is sitting 223,000 right now
I would think you would be getting a code for a bad purge selonoid or vent valve.
Maybe an injector leaking?
OP
OP
smokymtn65
Full Access Member
I did a test last fall or earlier this year to check for injector leak down and there was none. Wont cost me anything to check it again though but time. After all these headaches hard to look at it fresh you know. partly why I went to another tuner, Its my wife's daily driver so data logging is not something i want to put her through but I will do some this weekend So i know more about engine temp range it happens with.
I think a leaky injector (especially given you tested them) is probably a long shot, just trying to figure the gas smell.
You might try a flood clear procedure when you are about to restart when hot. If it fires right up after a short flood clear, you know something is causing a lot of gas to leak into the intake after shutdown.
The canister vent valve opens when the ignition is shut off but closes when the ECU commands it to, so you may smell some venting back by the tank when you shut off the truck. It vents to prevent pressure buildup as the fuel temp changes and the fuel expands.
Last edited:
If it's still on the original fuel pump, you're on borrowed time.
I'm a little worried about the comment that oil pump relief valve stuck open. Do you mean the one on the pump or the one in the pan? And was the one that failed original or replaced when you did the cam swap?
OP
OP
smokymtn65
Full Access Member
It was the one in the pump, I was told it was replaced @ 180k just before I bought it. It would run 80 psi cold 60+ hot
OP
OP
smokymtn65
Full Access Member
So smelling gas at shut off indicates the casnister vent is working correct? is the there a way to test the purge solenoid?
I believe you can test it with a Tech2.
OP
OP
smokymtn65
Full Access Member
I was afraid that would come up.. LOL Never have got it to communicate with the CANDI again..
Thanks for that. I installed a new Melling when I put mine back together, along with a new relief valve in the oil pan. It runs 55 psi when cold and 45 when hot, and 30-35 at hot idle. Fingers crossed that my workmanship and parts choices are good enough to cover the next 4500 miles of towing out to Yellowstone and back reliably. My goal was to end up with better reliability than when I started, but when I hear horror stories it always makes me bite my nails.
Also, I see that your cam is a 1-bolt cam, so you retained VVT. Makes me wonder if your stalling issue has a similar root cause to the one that guys running the L92 have been reporting for a while, which has 2-3 different potential root causes - one of them being low hot oil pressure not being enough to shift the cam back to idle profile, and another being the printed circuit board on the bottom of the fuse block starting to separate.
Last edited:
OP
OP
smokymtn65
Full Access Member
No i dont have VVT mine is a LC9 Went back with the Melling I will have to look part number up, but I know low op effected CAM bearings when pump failed. I have low OP now but, it does have some lol . 40cold 15 hot running 15w-50 Till I find a block and do a total build it is what it is. But I don't think that should have anything to do with the hot long crank issue. I like you, was hoping to just have a reliable DD and occaisional TT puller.Thanks for that. I installed a new Melling when I put mine back together, along with a new relief valve in the oil pan. It runs 55 psi when cold and 45 when hot, and 30-35 at hot idle. Fingers crossed that my workmanship and parts choices are good enough to cover the next 4500 miles of towing out to Yellowstone and back reliably. My goal was to end up with better reliability than when I started, but when I hear horror stories it always makes me bite my nails.
Also, I see that your cam is a 1-bolt cam, so you retained VVT. Makes me wonder if your stalling issue has a similar root cause to the one that guys running the L92 have been reporting for a while, which has 2-3 different potential root causes - one of them being low hot oil pressure not being enough to shift the cam back to idle profile, and another being the printed circuit board on the bottom of the fuse block starting to separate.
