I normally only need to adjust cranking ve.
gtstorey... thanks for the information, but let me ask you this. does injectors come with cranking fuel data?
Injectors come with data for low flow characterization which will be used for cranking fuel calculations.
04silverado6.0..... ok why do you have to adjust cranking ve? and how?
gtstorey... thanks for your help
dflintstud1.... can I get more information on Fuel transiet boil tables please
Cranking ve is a calculation of the main ve. You can reduce it in small percentages to help with starting issues. Honestly i believe you have other issues as stated by others.
Hey. Why are you condescending to him? He's right.
See the cranking VE table? Now see the FA Mult table? How do you think the FA ratio is figured? Injector data. Ok? That's what I was telling you on the other post you made.
Now, you said you can't get the real data. Fine. You can make it work with cranking VE primary table, Charge Temp vs ECT, and the cranking fueling tables. If you hover over the tables there's a description below. Should be able to figure something out.
Siriuc1024 ... Im not condesending anyone. I dont understand how asking a question about data sheets could be condensending. I dont know I never bought new injectors like this. At Gm we got injectors from everyone. only injectors we had to input information on was deisel injectors. I PM you where and why i using the Deka injector information a few days ago. . Sorry if you think Im being condecending but Im not. I also know replacing my injectors with new ones with data will not fix my issue. Yes Im not 100% sure these are pre Deka's but I know they are really close. Im just trying to understand tuneing. After more then 20 years wrenching/teaching for GM Im perty good at diagnosing. But we never had tune. So what Im asking is more knowlege on tuning... forget I posted that these are unknown injectors and call them Deka 80 lb injectors. I started changing my cranking VE table and seems to be helping...alot. And I can see the discription of these tables just asking for more information about htese tables. I hoping with more information I can figure out this issue....Attached in my .hpt tune
The issue is simply that the calculated fuel metering doesn't match what's coming out of the injectors. You have to use those tables to make it work now. Increasing cranking VE makes the injectors put in more fuel. The cranking fuel tables do the same thing, but you can more precisely control what happens when.
For example, the First and Second Pulse Mass tables. Mass of fuel. That's derived from the injector data entirely. Since there is error there compensate. Maybe it starts fine cold, but hot not so much. Those tables are mass vs temp, so try increasing mass at higher ECT.
How do I know it's ECT and not IAT? First Pulse Mass has a soaktime multiplier. Soaktime is above at Soaktime ECT thresh. In totality, you can adjust for how hot an engine is and for how long it's been hot.
I'd start by increasing the Cranking FA table vs Cranking Time.
That's there to estimate latent fuel on the port walls. Impact is how much has landed on the walls. Boil time is rate of evaporation. One could argue that these need adjusted for something like ported heads or rec port swaps, but these tables are normally left alone. If there are problems with lean spikes during transients, such is when the pedal is stabbed WOT, then adjust.
LOL at this......
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Worst thing is, if he plays with it enough to get it running decent, with unknown injectors from a "somewhat good company", I wouldn't be surprised if a week later it doesn't idle or start because the "injector shaped object" he has is flowing something totally different.Originally Posted by edcmat-l1
ok thanks guys.. The car runs great now. nly issue is hard start warm. seems like playing with the ve cranking table is helping. I put it to my main ve table and then smoothed the numbers. will try again over the weekend.
gtstorey, Im not adjusting anything that I would affect the running of the car just playing with the craking fuel and cranking ve table. do you know if that will effect the running of the car?
siriusc1024 ,I will look into this. Makes sense to try increasing fuel on warm cranking to fix the issue.
everyone thanks ...
What we are trying to get across... is that Pro tuners rarely mess with these tables because they fall inline if the injectors are characterized properly. Or something I don't see being brought up... is other aspects of the tune is off. First step though is inputting the right data into the tune for the hard parts you have.
Imagine a recipe calls for 150 grams of eggs. If you don't know 1 egg = 50 grams than your recipe would be off. The solution would not be to change the recipe (these tables you are asking about).. The solution would be to figure out how many grams per egg.
Sorry for the shitty analogy.. and I don't know wtf a egg actually weighs.
A good injector company will give you data. In the older days when a 42 lbs injector was big.. this was less of a big deal. Now that the injectors can be 1000-1300 cc.. this is critical.
Also a big factor is a ton of counterfeit injectors on the market. They will be listed as Siemens or Bosch but they aren't.. With my business we get emails all the time from "quality injector companies" from china.. prices are like $20 each. You can guarantee are just garbage.
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The fuel injector data is critical because all the PCM's math is done assuming that information is correct. The PCM needs to know how much air is coming so it can do the math to squirt the exact amount of fuel to run right. If the PCM is doing the math with bad injector data it is NOT going to fuel right. Then you start to lying to the PCM by telling it bad air flow information to get it to provide the right fueling. You'll end up with a bad tune and driveability problems. Which why everyone is focused on trying to tell you make sure your injector data is correct. You also don't want to spend a bunch of time tuning with bad injector data, once you do correct the data, or change to bigger injectors, all that tuning goes in the trash and you start over. Injector data is like primer before a paint job.
There is a spreadsheet crankingVEv1.1.xls that will build a cranking VE table from your VE table. Again, if your VE is bad because it was adjusted bad injector information, well your cranking VE is going to be full of lies too.
Here is how the PCM works...
https://www.youtube.com/watch?v=QVGC9Jydujo
changing the cranking ve table and the cranking fuel FA stage 1 vs time not solve the issue. I called a friend who is going to let me try his injectors. Its an LSA setup like mine. He has the data information. It only takes a few minutes to swap the injectors. I believe he said they are ID1050s.. he also gave me the ok to tell you guys what injectors I am using. My injectors came off a 2010 CTSV that I had to replace the supercharger per the recall. It had prototype GM 96lb injectors. GM techline wanted me to replace them and reflash to the car. Along with the fuel rail. I did the repair and they never called for the parts back. 2 years later the parts manager was going the throw them away. he did send back the supercharger. He oked me to grab the injectors and rail. I called my buddy at GM engineering and he ran the vin. He said was the one who gave me Deka's information. He said these were being tested for them. I didnt want to post anything because I did not want to get the parts manager or my engineer buddy into trouble. Well the parts manager is retired and my engineer buddy is about too. I called him today and was asking about these injectors. he confirmed that they are Deka's. he should be over Saturday. I will try his injectors with his number and see. Been turning wrench for a very long time. I known the issue is not mechanical or electrical. thats including the ecm. Tuning is my last resort. thanks everyone for your help..
Dodgez thanks for that video I may use that the next automotive class I teach
Here's this if you want to try it. Updated Deka 80 data and minor tweaks to various tables.
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