2009 Escalade - takes a while to start but idles and drives perfect

[AZ03Cobra]

Im really scratching my head on this one, and looking through as many threads as I could, I couldnt find any similar issues where only the start is the issue. I just swapped a LS3 crate engine in (brand new from GM), and mods listed below. It ran decent on the old engine with the same mods, but would have warm restart issues at times, just never start issues, where now the start is the problem, but I can immediately restart it just fine.

2009 Escalade ESV
LS3 crate engine
Whipple supercharger with their map sensor
Flowtech Stealth LS3 cam
ARH Long tubes with cats, custom true duals
Circle D 2400 stall 300mm converter
Brand new battery

Log and latest tune attached

I have tried increasing and decreasing starting airflow, starting fueling, starting timing etc. I have been driving it all day and I would say the starting is getting "better" in that when I Started the day with the tune from my old engine. When I started tweaking, id have to use some pedal to get it going, or put the pedal to the floor, so I thought I was making progress, but nothing I do seems to make it better, and when I add a lot of air, the starting actually gets worse. It idles fantastic, trims are all good, I Did all the VVE tuning this morning, I just did some WOT pulls and they were clean as could be, but nothing I do will get it to start up EXCEPT if I start it, turn it off, then immediately restart, for the first 30 seconds or so it fires right up, but much beyond that, its back to crap. Im running 850cc injectors and have their values put in, and stock flex fuel pump. I thought maybe the pumps are going, but I can cycle the ignition a few times and it doesnt fix it, and the soft lines are still nice and firm with fuel pressure. I dont know a ton about the newer pumps, but id imagine they prime just the same as the old stuff, but if im wrong, I guess I need to buy some pumps. I did see a voltage drop on some of the starts, so I tried starting both with a charger attached, then I replaced the battery since it was in the car over a year ago when I bought it, nothing changed though.

[blindsquirrel]

What is the fuel pressure? How long does it hold pressure after key-off?

[blindsquirrel]

Injector data not correct. (I know, broken record... but it keeps being done wrong, I dunno man.)

screenshot.12-05-2024 18.54.54.png

The table that was changed isn't used, the one that is used wasn't changed from stock L9H data.

[AZ03Cobra]

I have to get a gauge and adapter, but usually if it?s dropping pressure, a couple key cycles will supply enough. I?m not sure how the newer fpcm setups work though so that might be my last thing to check if it?s not like prior vehicles that prime on key cycle.

[blindsquirrel]

Man, I wish they'd invent a way to verify fuel pressure with a keyboard, then I wouldn't have to spend so much time bitching at people for trying to do work on EFI without a gauge.

And the injector data thing? Can you share or link to the datasheet?

[GHuggins]

After you fix your injector data and verify fuel pressure (you need something in the 50's), you'll need to set your VE table to read into boost via your boundary settings then tune the VE and your MAF back in. After that or before your left most column in the cranking air should be your highest numbers. You can hold the throttle open slightly via pedal at 30% just to see if it's air related.

[AZ03Cobra]

Here you go.

[AZ03Cobra]

Injector data not correct. (I know, broken record... but it keeps being done wrong, I dunno man.)

screenshot.12-05-2024 18.54.54.png

The table that was changed isn't used, the one that is used wasn't changed from stock L9H data.

Thats my fault. I built a new file from scratch this morning to start over and clicked on the wrong field. Fixed it now and going to try it just to see if magically that is what I did wrong.
Thank you

[AZ03Cobra]

After you fix your injector data and verify fuel pressure (you need something in the 50's), you'll need to set your VE table to read into boost via your boundary settings then tune the VE and your MAF back in. After that or before your left most column in the cranking air should be your highest numbers. You can hold the throttle open slightly via pedal at 30% just to see if it's air related.

Injector table fixed, and the fuel pressure sensor is reading 60 psi at the tank, I will try to get a manual gauge on it this week. Holding the pedal at 1/3 does make it fire more quickly, but no amount of air ive added in the starting airflow has changed it.

edit - logged it with just the ignition on, the fuel pressure is bleeding down after I shut the engine off. I havent had a lot of sleep the past few weeks, but looks like I need to order the fuel pumps I was putting off. This log shows the pressure bleeding off, then going back to 60 psi once I go to crank. I will have to see how low it goes after Ive let it sit a while.

[blindsquirrel]

The pressure sensor is often an expected/calculated/estimated value, not live and accurate. Yes, there is a real sensor there with 3 wires and everything and yes it does output an actual variable analog voltage, but the data displayed is often not a live value converted direct from the sensor's voltage.

Mechanical gauge. Mechanical. Like a diagnostic tool. For diagnosing a fuel system.

[AZ03Cobra]

Mechanical gauge. Mechanical. Like a diagnostic tool. For diagnosing a fuel system.

Speaking of broken records, your douchebag elitist attitude gets old. I can't make a fuel pressure gauge pop out of thin air, so this is what I have until I have time to go get one, or have Amazon deliver one. Youve made your point, move on.

[Alvin]

The fuel pressure looks reasonable on start up. This is a FPCM equipped truck so it has a sensor in the fuel line. I've never found them untrustworthy.

I would keep adding the to the starting airflow table. I usually make 20% changes when you have a no start or very delayed start. That should get you in the ball park.

Fix the injector data.

Sometimes long starts can be caused by leaky injectors. Not a good way to diag that directly other than popping the rail up and watching them with key on fuel pressure. They will drip a bit if leaking.

[edcmat-l1]

Instead of adding to the startup airflow table you can reduce the cranking fuel. Typically, if it takes more throttle angle to start it's too much fuel, especially with larger injectors.

[hjtrbo]

I've never found them untrustworthy

Beware! The reported fuel pressure bit me in the ass once. Reading the sensor volts with a math transform is the most reliable.

https://forum.hptuners.com/showthrea...l=1#post673286

[AZ03Cobra]

The fuel pressure looks reasonable on start up. This is a FPCM equipped truck so it has a sensor in the fuel line. I've never found them untrustworthy.

I would keep adding the to the starting airflow table. I usually make 20% changes when you have a no start or very delayed start. That should get you in the ball park.

Fix the injector data.

Sometimes long starts can be caused by leaky injectors. Not a good way to diag that directly other than popping the rail up and watching them with key on fuel pressure. They will drip a bit if leaking.

I fixed the injector stuff last night when I made that log, I?m going to play with it more tonight when I get off work. I hope my injectors aren?t having issues, I bought them in December, but these days it doesn?t seem like parts are made to last anymore.
Thank you!

[Alvin]

Beware! The reported fuel pressure bit me in the ass once. Reading the sensor volts with a math transform is the most reliable.

https://forum.hptuners.com/showthrea...l=1#post673286

Thanks for the heads up.. I looked an it looked like it the gauge followed what was in the scanner? I must have missed it. I've recorded the gauge face and HPTuners logginng at the same time with video. That can be helpful finding weird things like that.

[hjtrbo]

Thanks for the heads up.. I looked an it looked like it the gauge followed what was in the scanner? I must have missed it. I've recorded the gauge face and HPTuners logginng at the same time with video. That can be helpful finding weird things like that.

Delta fuel pressure from sensor volts in yellow. How it should be, flat(ish).

Delta fuel pressure reported from fpcm in white. Taking a dive and not accurate to the gauge. 7 psi out at the end of the pull.

[Alvin]

Delta fuel pressure from sensor volts in yellow. How it should be, flat(ish).

Delta fuel pressure reported from fpcm in white. Taking a dive and not accurate to the gauge. 7 psi out at the end of the pull.

Humm... maybe the test could be done a little more scientific. In the video it looked like FP dropped a bit and that is what the raw sensor looked like to me. I didn't/don't look at delta pressure specifically. Thanks for sharing.. I'll look harder into it on my end when I get an opportunity to have a real gauge/ logged sensor.


I wrote in another thread not log ago about how much the 1:1 regulators vary.. at some pressures its 1.1 at others its .80 etc. These vacuumed referenced regulators are very far off from what they claim to be.

[AZ03Cobra]

Humm... maybe the test could be done a little more scientific. In the video it looked like FP dropped a bit and that is what the raw sensor looked like to me. I didn't/don't look at delta pressure specifically. Thanks for sharing.. I'll look harder into it on my end when I get an opportunity to have a real gauge/ logged sensor.


I wrote in another thread not log ago about how much the 1:1 regulators vary.. at some pressures its 1.1 at others its .80 etc. These vacuumed referenced regulators are very far off from what they claim to be.

Any insight on the ?good? ones? I was going to snag a racetronix or aeromotive regulator with my pump setup eventually (or possibly now if mine is on its way out). The whipple rails have a 1/8 npt port so i will probably toss a manual gauge there for the meantime to log pressures on shutdown.

[hjtrbo]

Humm... maybe the test could be done a little more scientific. In the video it looked like FP dropped a bit and that is what the raw sensor looked like to me. I didn't/don't look at delta pressure specifically. Thanks for sharing.. I'll look harder into it on my end when I get an opportunity to have a real gauge/ logged sensor.


I wrote in another thread not log ago about how much the 1:1 regulators vary.. at some pressures its 1.1 at others its .80 etc. These vacuumed referenced regulators are very far off from what they claim to be.

In the video the fp dropped a psi or 2 which my screen shot shows. Boost drops off a little to pull the delta back in my favour.
You'll need to dig into this when you have time. You should see what I'm claiming is 100% accurate. The GMW standards document I have for the fpcm also backs up my claim. The reported fuel pressure is based on an internal calculation which models the fuel pressure drop in the fuel system. Raw sensor volts tell the real story.