Fuel Injector Sizing

[4pointslow]

Vapor management valve

With your logic and perseverance I knew you would eventually succeed.

Thanks!

Have you ever shut off your vapor management valve in your tune?
The valve has a built in vacuum leak just like the EGR solenoid. The pcm closes off the vacuum leak to allow the vacuum to open the EGR valve or in this case to open the Vapor management valve and control how much flows.

For tuning purposes I was thinking of turning it and adaptive off.

 

[2000StreetRod]

never tried it

I've never turned off the vapor management valve and I still haven't turned on adaptive learning. It seems to me there would be little flow thru the valve and to the intake manifold unless the gas cap is vented. If it's not vented then the vacuum would be working against the fuel pump as fuel is used. My aftermarket locking fuel cap looks like it could have a center port for venting but I sure can't suck thru it. I guess I need to learn about gas caps.

 

[jd4242]

I didn't lower the pressure. I rescaled the injector data.
Raising the pressure lowered duty cycle to 80 something when it was hitting 90% with the pressure at 39.15.
Still need to raise it more, will have to be careful rescaling injector data and retest with each pressure increase to see if it will still go through the HEGO test afterwards.
Wondering where a good safe duty cycle should be, need room for increased airflow down the road.

So what i gather from all this is that your new injectors at 39psi are to small??

Thanks!

Have you ever shut off your vapor management valve in your tune?
The valve has a built in vacuum leak just like the EGR solenoid. The pcm closes off the vacuum leak to allow the vacuum to open the EGR valve or in this case to open the Vapor management valve and control how much flows.

For tuning purposes I was thinking of turning it and adaptive off.

I dont know if you can ""turn it off"" in obd1 but i told my tuner i dont run one and run a vented cap..its just a stock cap with a 1/4" hole drilled in it and i then stuffed a cigarette filter in it..lol

if i have a full full tank and take sweeping long right turns i do notice ""some"" gas does leak..ive been looking at little one way valve to stick in the hole but havent got around to it

 

[4pointslow]

I've never turned off the vapor management valve and I still haven't turned on adaptive learning. It seems to me there would be little flow thru the valve and to the intake manifold unless the gas cap is vented. If it's not vented then the vacuum would be working against the fuel pump as fuel is used. My aftermarket locking fuel cap looks like it could have a center port for venting but I sure can't suck thru it. I guess I need to learn about gas caps.

The tank is vented through the Canister Vent Valve, the only time the valve closes is when the monitor test runs for the evaporative system.
Purge can happen at any time, when it does it sucks air in through the open vent valve and through the canister ripping the HC's out and sucking them into the intake manifold. If you were to watch the O2 readings when it first happens the voltages usually go instantly rich, then STFT takes away fuel and the canister gets emptied out and it goes lean. Eventually the O2's start switching again.

 

[4pointslow]

So what i gather from all this is that your new injectors at 39psi are to small??

if i have a full full tank and take sweeping long right turns i do notice ""some"" gas does leak..ive been looking at little one way valve to stick in the hole but havent got around to it

Yes, 60's too big (61% duty cycle) ( and couldn't get them to run and pass the HEGO test)
47's too small (91% duty cycle) But the HEGO tests runs and passes.
Now with fuel pressure slightly higher DC is 80 something, going to jack it up some more.

No one way check valve! The tank needs to be able to breath in both directions.

 

[jd4242]

Yes, 60's too big (61% duty cycle) ( and couldn't get them to run and pass the HEGO test)
47's too small (91% duty cycle) But the HEGO tests runs and passes.
Now with fuel pressure slightly higher DC is 80 something, going to jack it up some more.

No one way check valve! The tank needs to be able to breath in both directions.

Id offer you thise 50s i have for cheap but they are ev1 and old school fat bodies, think it would be going backwards. .ill keep an eye out for some ID725, ID850 or bosch 72s for ya..you have Ev6 with UScar?? Opposed to going to EV14??

Ewww hhhmmm good point!!!! Well guess ill keep my cigarette filter cap lol

 

[jd4242]

Have you looked at these?? Priced good.ev14 can come in a 60mm length,just need the connector adapters or new pig tails
http://www.deatschwerks.com/product...e/6-cylinders-ev14/long-60mm-ev14-6-cylinders

 

[4pointslow]

Injectors

I have the older style connector but I have the adaptors on with the new 47lb injectors.
I am keeping them on for a while. Need to experiment with them.
Also going to go through Inspection in March, after that I may change them.

 

[4pointslow]

WOT Duty Cycle w/Fuel Pressure at 43.5

So on a really cold day with the fuel pressure raised to 43.5.....
My injector duty cycle still hit 90% with the 47 lb. injectors.
This was a WOT run in D2 which is 3rd gear on the 5R55E, I took it to the rev limiter. I have never hit MAF counts this high before, the new 8 rib belt set up is really working good. The bad, duty cycle is too high for safety of the injectors/pcm.

My plan is to raise the fuel pressure, eventually to a high of 55 psi. With 20lbs of boost I would hit approximately 75 psi fuel pressure at WOT.
After raising fuel pressure I will have to recheck to see if the HEGO monitor runs/passes. One thing I noticed is that after raising pressure from 36.15 to 43.5 is that the HEGO test runs/passes at a higher MPH/Load/MAF count now.
It used to be at around 35mph and now is at around 48mph.
I have made a tune with some transmission shift point changes to see if I can get it to run by going into O/D sooner and at a lower mph.

I played around with a formula that 2000streetrod posted to calculate injector pulsewidth in milliseconds. I will post on that next.

 

[4pointslow]

HEGO Test Running Injector Pulsewidth

Using this formula posted by 2000streetrod here.....
http://www.explorerforum.com/forums/showthread.php?t=409273

Formula: PW in ms = 1/[(rpm/20,000) * (pip to pip tics/PW in tics)]
Note: formula may be different for diferent vehicles/engines/pcm's.

I wanted to see what my injector pulsewidth would be when the HEGO test was running and passing vs not running and passing.

Passing with the 47lb injectors and the fuel pressure jacked up to 43.5=
1/[(2028/20,000)*(1851/746)]
Answer = 3.97 (aprox)
MAF counts = 342
Load = .364

Here it is passing with the fuel pressure at 39.15
1/[(1954/20,000)*(1921/684)] =
Answer = 3.64 (aprox)
MAF counts = 276
Load = .313

Here it is with fuel pressure at 43.5 at around 34 mph not passing, the one thing I see is that the load is lower.
Load when the test runs and passes is about 36, when it doesn't run and pass it is around 24.
1/[(1944/20,000)*(1931/486)]
Answer = 2.59 (aprox)
MAF Count = 256
Load .235

The pictures are in order with the above posted calculations.

 

[2000StreetRod]

inconsistent vehicle speed

The vehicle speed in the first graph (47.8 mph @ 2028 rpm) is inconsistent with the vehicle speeds in the 2nd and 3rd graphs (34.6 mph @ 1950 rpm). The first vehicle speed should be 36 mph @ 2028 rpm if the same gear is engaged. 47.7/36 = 1.3 so I suspect the vehicle was in 5th for the first graph and 4th for the 2nd and 3rd graph.

 

[4pointslow]

Vss

Yes, talk about weird. It wont run/pass in 4rth anymore. Only 5th now.
I am hoping that getting it into 5th sooner will get the load value higher and run the test at a lower mph, that would allude to the pcm preferring a higher load value to be able to run/pass ressure maybe.

I wont drive the truck on the road right now, all that metal rotting "brime" on the roads around here. Waiting for a good rain to wash it and the remaining snow away.

 

[4pointslow]

Passed at 35 MPH in 5th

I changed the shift points to make the Transmission shift into 5th sooner. I got the HEGO test to run/pass at around 34 MPH now.
The PCM seems to like about 30% load with the fuel pressure at 43.5 psi.
MAF counts 295 now.
This was done on a back road that I can not get up to 47mph on. Before changing shift points I had to get on the highway to get the HEGO test to run/pass since jacking the pressure up to 43.5

 

[4pointslow]

Check this crap out!

Here is some bad data for you!
I went back a few post's and was looking at this chart and realized it is messed up.
When I went from 36.15 to 43.5 I used the value file and the math equation I posted earlier to calculate the needed changes to injector data based off the fuel pressure change, I am going to do that again since there is bad data on this sheet.

 

[4pointslow]

Correct Multiplier for 54.96 psi

39.15/54.96 = 0.7123362445414847
sqrt of 0.7123362445414847 = 0.8440001448705354
Reciprocal of 0.8440001448705354 = 1.184833919848905

So 1.1848 is the correct multiplier for changing injector data

from 39.15 to 54.96 psi.

 

[2000StreetRod]

incorrect calibration summary

Nice catch on the bogus entries in the calibration summary. I did a quick Google search for the Bosch part and the Ford equivalent and couldn't find a calibration summary for either one.

Last weekend I installed Advantage III on my new computer but the program would not recognize my dongle. I tried different things for several days and then called SCT. I let a technical support rep remotely logon and he spent almost an hour before he found the problem. Something to do with the McAfee anti-virus software and the USB driver for the dongle. I hate not being able to turn off "tap to click" in Windows 10.

 

[4pointslow]

10

Did the McAfee come with the computer? I always delete that and just use Windows Defender or Microsoft Security Essentials(for Win 7).
McAfee and Norton antivirus software used to be great stuff but it seems to just slow things down and cause problems like you mentioned.

I also hate the tap to click feature on my laptop. There may be a way to turn it off but I have not looked into it yet. I barely use my laptop anyway. Maybe I would use it more if it had Windows 7 on it.

 

[Dono]

Interesting, I really dislike bloated Av programs also.
I'm a security essentials and malware bytes guy. For me, the combo is perfect. I don't bother having malware bytes run all the time if the computer I have at the time is weak in the processor and ram department.

Any new news on injector testing. Its super impressive you found that error.

 

[2000StreetRod]

Non-linear parameters

I've found the best anti-virus protection is to run obsolete operating systems. Nobody bothers with them.

I've been thinking about your calibration error discovery. As you know I've experimented a lot with injector slopes and breakpoints but I haven't been successful in tuning with them. Your calibration summary and some others have unexpected values for some fuel pressures.

The last one (my Deka 60s) seems to be the only reasonable one with values increasing with pressure. But even with them I've encountered some strange things in the vicinity of the breakpoint.

 

[decipha]

some injectors do have non linear slopes

back in the day it was common to use the LPG 160 lb injectors, at low pulsewidths you could increase the pw and LEAN OUT the injector, they had very non linear low flow control

although the data may look wrong it COULD be correct, i know injector dynamics have non linear multipliers as well