Fuel rail pressure
- Thread starter BM06lbz
- Start date
Pretty simple.
MPa is the pressure being used. 1 MPa = 145 PSI
uS is the time the injectors are open for. us = microseconds or 1 millionth of a second
The mm3 or quantity is how much fuel was delivered during that test.
Lastly the return is how much fuel was returned from the return port.
For calculating the balance of the injectors, you'll compare the mm3 from the same pressure and open time
It "could" work in theory but I don't know if it would in actuality.
My OCD forces me to put them in the correct cylinders based upon the injector number on the sheet. Whatever injector is at the top of the sheet is what goes in cyl 1 and so on.
If I have any major outliers I sometimes move it like mentionied but I have only done that on the Cummins side not the GM/Ford side.
Well we finally got the LBZ started tonight and boy she sounds good- only have one problem tho
And that’s white smoke. When you’re at idol, it’s not super bad, but as soon as you gas on it a little, you can definitely see it. So at this point, I’m wondering if it’s just cause it’s not tune for 45 overs and RGE delete , or maybe there’s a deeper problem in the system 
other than that, it sounds and runs phenomenal
And that’s white smoke. When you’re at idol, it’s not super bad, but as soon as you gas on it a little, you can definitely see it. So at this point, I’m wondering if it’s just cause it’s not tune for 45 overs and RGE delete , or maybe there’s a deeper problem in the system other than that, it sounds and runs phenomenal
Get the truck tuned properly first. If the issue persists, then worry about it.
OK makes sense it’s really not bad at idle and maybe it just needs warmed up. I checked, and there was absolutely no blow by this morning. I do have an autel so I can read injector balance. also, my fuel return by the quick connect, was kind of kinked so maybe if the return wasn’t getting past? Just some thoughts I had ,but could definitely be it not being tuned.
I will go a little farther in depth on the explanation of this sheet. So the readings on the sheet are a volume which can be directly translated to a hp number at the crank available if everything is good. On a boost only setup I will go 4xmm3=Hp at crank and a heavy nitrous with boost combo will go 5x. This means on your sheet at 1350us you technically have 518hp available and at 1750us you have 670.8hp at that pressure on boost only. Hope this helps.
I really appreciate all the info on here. Finally got my truck tuned today. And it drives awesome
. Had some problems right after putting the tune on it still blew white/blue smoke like crazy. Then I realized I had forgot to reprogram the injectors. I did that and it still smoked kinda bad, then the smoke got less and less and about a 2 miles down the road it completely stopped smoking and been running fine so far
. Had some problems right after putting the tune on it still blew white/blue smoke like crazy. Then I realized I had forgot to reprogram the injectors. I did that and it still smoked kinda bad, then the smoke got less and less and about a 2 miles down the road it completely stopped smoking and been running fine so far 
It makes you wonder if there was oil, fuel or something in the exhaust from before that took a while to burn out. I have seen that with blown head gaskets that put a bunch of antifreeze in the exhaust. The first test drive when you got on it would leave a huge white cloud.
I'm thinking the same.
When doing experiments with my FICM boards, if I had the injectors connected wrong or something in the programming, it would dump lots of fuel into the exhaust and smoke badly. After correcting it or returning to stock, it would take a few miles to clear up due to how much fuel remained in the exhaust.
Oil or coolant can do the same
Yeah, I wouldn’t be surprised at all if that was the case . Because before it completely won’t run, it ran terrible. I’m sure it got a lot of oil and junk in the exhaust
Hey, so I finally got my DSP5 switch installed and process went great . Having a couple problems either with my tunes or my truck. I also noticed it before the DSP5 switch when I was running the optimized stock tune. It seems like when I takeoff the power feels good until I get into about third or fourth gear and then it just gets terrible sluggish and I noticed last night I had my cruise at 60 going up a hill and the truck didn’t keep up with the cruise. It just kind of bogged down so I had to like floor it to get a higher gear to speed up if that makes sense. It seems like that economy tune is even worse. Like it feels like you’re almost going into limp mode. Other than that the street tune and race tune run pretty good although it seems like there is a little lag when you need to get up and go. So just curious if this is a boost issue,tuning issue or a fuel issue,hopefully this makes sense
Only thing I can think of is when I pulled the lower valve cover off I kinked the fuel return line by the quick disconnect . I’ve messed around with it after that though and fuel should still be able to get through
Send me a data log, I’ll take a peek and see if it’s obvious.
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A hose clamp put over the kinked area, not too tight, will 'stop the kink' and restore the flow.
Here is his log for transparency.
It sure seems like a MAF issue overall as I doubt the scaling would be that bad.
It sure seems like a MAF issue overall as I doubt the scaling would be that bad.
Well, I changed my O’Reilly’s maf sensor out to my original OEM one. Took it for a test drive and it created boost way faster, and it drove just great ! - thanks again for all the support
Cheap replacement parts strike again....
That was my first thought haha.
We’ve all seen it too many times where parts store brands are poop.
That’s why will not recommend or install anything but GM or Bosch sensors on these pigs.
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