Turbo on 2000 Limited 5.0

[Dono]

ok, here's the equations I'm using:
Analog 1: (v*13)-32.0 boost/Vacuum AEM digital gauge
Analog 2: (v*3)+7.35 Taken right from the livelink equation drop down menu for LC-1

I need to start fresh, with fresh datalogs and forget everything we have been battling so for.
Today, fresh plugs and fix exhaust leak.
Then plug in factory maf, factory tune, etc and get a really good datalog.
In a perfect world, I would then add the slot maf and tune still with stock injectors. Even just a basic tune so the truck will idle and rev to 2000 rpm for datalogging, then add the 60lb injectors to the equation. For this, I need the pro racer package.
James emailed me and says he has no transfer numbers for the slot maf, and just does what he needs to do. This is great for him as he has the knowledge and experience, but not so good for me.

I'll double check my cut/splice wiring on my pigtail to the slot maf and see if I somehow mixed up a wire. Anything is possible I guess.

 

[Dono]

I gave James a call, and he said he would gladly sell me the pro racer package, but he doesn't believe it will help. He is absolutely certain that the first base file he sent me will get the truck running if there are no other issues with the truck.

Here is what we are going to do:

1. fix exhaust leak
2. replace spark plugs
3. re-install 60lb injectors.
4. double check slot maf pigtail wiring
5. install open loop tune that James is sending me and datalog.

He is really starting to think that the exhaust leak is the big issue.

 

[2000StreetRod]

equations are good

If you have the AEM 30-4406 then the pressure range is -30 to +35 or 65. Dividing the pressure range by the voltage range is 65/5 volts = 13. Adjusting for the lower value gives (13*v)-30 =vacuum/boost

The other equation using 3.008 instead of 3 only makes a difference of .04 at the maximum of 5 volts so its not worth changing.

For my tunes James had access to the Lightning 90 bench flow MTF values but used a combination of injector slope changes and MTF changes to get the actual lambda to equal the commanded lambda throughout the airflow range. I tried to use just injector slopes with my Deka 4s but could never get the mixture lean enough even using the Advantage III limit. Changing the MTF from established bench test results invalidates the PCM calculated load which impacts spark advance.

 

[2000StreetRod]

a good plan

That sounds like a good plan to me. James didn't give up on me even though he basically had to start over twice: 1st time when I switched to the fuel pump controller; 2nd time when I went from 3 functional injectors to 6.

I gave James a call, and he said he would gladly sell me the pro racer package, but he doesn't believe it will help. He is absolutely certain that the first base file he sent me will get the truck running if there are no other issues with the truck.

Here is what we are going to do:

1. fix exhaust leak
2. replace spark plugs
3. re-install 60lb injectors.
4. double check slot maf pigtail wiring
5. install open loop tune that James is sending me and datalog.

He is really starting to think that the exhaust leak is the big issue.

 

[Dono]

If you have the AEM 30-4406 then the pressure range is -30 to +35 or 65. Dividing the pressure range by the voltage range is 65/5 volts = 13. Adjusting for the lower value gives (13*v)-30 =vacuum/boost

The other equation using 3.008 instead of 3 only makes a difference of .04 at the maximum of 5 volts so its not worth changing.

Your math skills always amaze me. You make it sound so simple. I wish I had that vision.

I think James gets so busy, he has too many balls in the air and can only spend so much time on any 1 given thing in a day. This means he may not get thru all his emails in one day.

My header is at the exhaust shop, and they think they can have it done today. There is a lot of work to be done to fix the collector. I just hope I don't get the call that its all rusted out from the inside. Mental note, NEVER buy used headers.

 

[2000StreetRod]

closed vs open loop tuning

On my NA tune and my FI tune for the no load step test James left the PCM in closed loop and used the STFTs for instrumentation. I tried that method and didn't like it because the PCM is constantly cycling the fuel trims from slightly lean to slightly rich. I prefer the open loop method when STFTs are the commanded lambda from the base fuel table and do not vary except with rpm and TP relative. I use the wideband for actual lambda to compare to the STFT. The disadvantages of the open loop method are that narrow band O2 sensors are more accurate than wideband in the vicinity of 14.64:1 and running open loop is more polluting and could possibly damage a three way catalytic converter.

Is your exhaust manifold leak on the same bank as your wideband sensor?

 

[Dono]

Is your exhaust manifold leak on the same bank as your wideband sensor?

yup

You sent me some information about the computer doing funny things to the other bank that has an issue. That made me think that maybe this was happening to me. It doesn't make sense that my plugs are black and my logs have shown lean on both banks and adding a ton of fuel in to the cylinders.

My only concern is that if James base tune makes my truck run super rich I'll fowl plugs immediately again. When Tim and I did the initial start-up with the original base tune the air smelt like gas, and then we could smell gas in the oil. I'm hoping with the wide band o2 taken off of the ACC power source and direct to the battery we can capture this if it occurs.

At least this time I'll know what to look for immediately. I'm going to sneak out of work early and hope my manifold has been repaired. I really need my daily driver back in operation badly. Adding a turbo to a daily driver might not be the smartest thing I ever did. edit: header won't be done till tomorrow.

 

[2000StreetRod]

added air

I found an interesting instance in first base file over 160 degrees. The engine speed fluctuates but the MAF Add Cnts (airflow) stays almost constant.

Assuming the MTF curve is smooth additional air is entering the intake system. It could be from the IAC valve or some other source. I suggest that you disconnect the electrical connector to the IAC valve and see if the engine speed still fluctuates with the MAF ADD Cnts staying constant.

 

[4pointslow]

plugs

With those plugs the way they were, no wonder it wouldn't run correctly.
The header leak made things worse and the PCV modification may have also added to it. with new plugs and that header fixed up things should go a lot better. Got to go, lunch break is almost over....

 

[4pointslow]

maf

What I did learn is that by connecting the turbo air tube to the throttlebody and plugging in the slot maf with the 19lb injectors is that the truck is WAY to lean to idle. The stock tune allows for a little bit of idling before stalling, and the last tune James sent me allows for almost no idling at all on the 19lb injectors. This would be consistent with the fact that the 60lb injectors would flow way more at smaller pulse rates.

4pointslow, wouldn't we want the tune to be adjusted so that the slot maf reads the same flow rates as the stock maf, then adjust the injector slope rates for the 60 lb injectors?

What you stated is correct.

When the slot maf is installed it reads lower airflow, that allows more total airflow measurements (more than the stock maf would allow) when the tuning is finished but causes lean conditions till the MAF transfer function is adjusted.
Lean
The "tuning" tells the PCM that what you see at Idle is now more airflow so the PCM adds more fuel. That corrects for the different MAF.
Then the tune changes for the larger injectors comes in, if the smaller injectors were in there the larger injector tune would be cutting fuel from injectors that don't need it.
More lean.
The exhaust leak would also be worse when cold. When warm the metal around the crack expands and closes up the leak some. Either way if there is a leak pre O2 sensor, it actually sucks in air / oxygen and makes the O2 sensors look lean when they are not. The PCM then adds fuel so if all you had was an exhaust leak then the engine would be running rich, probably why your plugs are fouled.
Fouled plugs are when the porcelain is coated with oil or fuel, your case fuel. Fuel and oil are carbon based. Carbon conducts electricity, porcelain is supposed to be the insulator. If it gets coated with carbon (fouled) then the spark just runs up the carbon to the metal part with the threads on it (path of least resistance) instead of jumping the gap to get to the metal part with threads on it. Fouled spark plugs can not usually "be cleaned" except for with a spark plug sand blaster and even after that they are never the same. I have a spark plug sand blaster and used to clean the plugs for my 2 stroke motorcycles that I used to have years ago. The cleaned plugs never really worked well, loss of power mostly.
Fouled plugs cause misfiring. No fuel burnt, no oxygen burnt. O2 sensors only see oxygen not fuel so the pcm thinks the mixture is lean and richens it up making things even worse.
When tuning, the object is to get the A/F correct, no so much just having the Maf read the same airflow as before but if airflow didn't change and the mixture was right from the start then it may be close to where it was. So your thinking is on the right track. Now if the A/F mixture is way lean the tuner can add 5,10, 15 % (or whatever) to the MAF transfer to richen it up. If it doesn't respond by going richer then something is wrong with the vehicle(like misfires) and a tune wont fix it. So then you find the problem and you can get back to tuning.
Those plugs look like the main problem to me, but definitely not the only one. That header leak is a good one too with the wideband on that side. What a coincidence that it turned up on that side. lol.
Also, if you have a digital multimeter you can check for AC voltage at the battery to see if the diodes are bad in the Alternator. Just set it to AC volts, put the red lead on positive and the black lead on negative and let us know what the reading is. Something may be wrong with that thing, I saw voltages all over the place. AC voltage can make the PCM do awkward things. If the battery is bad get an optima in there. You might have to sell and arm or leg but they are awesome. Never corrode, and take some abuse too. Just don't fast charge them.

 

[Dono]

Okay, I'll check for AC fluctuation this weekend also.
I just bought stock heat range plugs this time (instead of 1 heat range colder) to help prevent fouling and gapped at .35.

The poor battery took a beating trying to get a log at 160 degrees. I wouldn't be surprised if it's bad now. Fully charged voltage was around 12.8v. I'll check, but I think that's low.
Edit....12.6 volts for a fully charged battery. I think I was just really hard on my battery and starter. I will confirm charging system works once I get this thing running.

 

[vroomzoomboom]

What you stated is correct.

When the slot maf is installed it reads lower airflow, that allows more total airflow measurements (more than the stock maf would allow) when the tuning is finished but causes lean conditions till the MAF transfer function is adjusted.
Lean
The "tuning" tells the PCM that what you see at Idle is now more airflow so the PCM adds more fuel. That corrects for the different MAF.
Then the tune changes for the larger injectors comes in, if the smaller injectors were in there the larger injector tune would be cutting fuel from injectors that don't need it.
More lean.
The exhaust leak would also be worse when cold. When warm the metal around the crack expands and closes up the leak some. Either way if there is a leak pre O2 sensor, it actually sucks in air / oxygen and makes the O2 sensors look lean when they are not. The PCM then adds fuel so if all you had was an exhaust leak then the engine would be running rich, probably why your plugs are fouled.
Fouled plugs are when the porcelain is coated with oil or fuel, your case fuel. Fuel and oil are carbon based. Carbon conducts electricity, porcelain is supposed to be the insulator. If it gets coated with carbon (fouled) then the spark just runs up the carbon to the metal part with the threads on it (path of least resistance) instead of jumping the gap to get to the metal part with threads on it. Fouled spark plugs can not usually "be cleaned" except for with a spark plug sand blaster and even after that they are never the same. I have a spark plug sand blaster and used to clean the plugs for my 2 stroke motorcycles that I used to have years ago. The cleaned plugs never really worked well, loss of power mostly.
Fouled plugs cause misfiring. No fuel burnt, no oxygen burnt. O2 sensors only see oxygen not fuel so the pcm thinks the mixture is lean and richens it up making things even worse.
When tuning, the object is to get the A/F correct, no so much just having the Maf read the same airflow as before but if airflow didn't change and the mixture was right from the start then it may be close to where it was. So your thinking is on the right track. Now if the A/F mixture is way lean the tuner can add 5,10, 15 % (or whatever) to the MAF transfer to richen it up. If it doesn't respond by going richer then something is wrong with the vehicle(like misfires) and a tune wont fix it. So then you find the problem and you can get back to tuning.
Those plugs look like the main problem to me, but definitely not the only one. That header leak is a good one too with the wideband on that side. What a coincidence that it turned up on that side. lol.
Also, if you have a digital multimeter you can check for AC voltage at the battery to see if the diodes are bad in the Alternator. Just set it to AC volts, put the red lead on positive and the black lead on negative and let us know what the reading is. Something may be wrong with that thing, I saw voltages all over the place. AC voltage can make the PCM do awkward things. If the battery is bad get an optima in there. You might have to sell and arm or leg but they are awesome. Never corrode, and take some abuse too. Just don't fast charge them.

i am so glad i got to meet this guy in person!!!!! lol

 

[2000StreetRod]

STFTs bank1 vs bank2

Excellent explanation John about fouled plugs and them causing lean conditions. What puzzles me is if the exhaust manifold is only cracked on one bank, and that is the only problem, then the STFTs for that bank should have been significantly different from the other bank before the plugs fouled. Also, only the plugs on one bank should have fouled. That's why I suggested disconnecting the IAC valve electrical connector.

I suspect there is another "leak" causing lean conditions on both banks. As I remember Jakee had a rear mounted turbo and there were problems configuring the PCV system. I know he had a "catch can". I don't remember how he configured his turbo cooling. For some reason he has deleted a lot of his old posts.

I suggest getting the engine to idle with the slot MAF sensor and the Dekas but with the PCV port capped. There will not be any boost during the no load step test so it shouldn't matter if the turbocharger is disabled. However, if exhaust gas is passing thru the turbo and it is spinning it probably should have lubrication/cooling.

 

[ahodges]

I'm learning so much by reading this thread! :thumbs up:

 

[2000StreetRod]

Jakee's PCV related posts

I went thru Jakee's rear mount turbo thread for PCV related posts:

http://www.explorerforum.com/forums/showpost.php?p=1946455&postcount=32

http://www.explorerforum.com/forums/showpost.php?p=1973441&postcount=88

http://www.explorerforum.com/forums/showpost.php?p=2222087&postcount=430

http://www.explorerforum.com/forums/showpost.php?p=2953533&postcount=438

http://www.explorerforum.com/forums/showpost.php?p=2953542&postcount=439

http://www.explorerforum.com/forums/showpost.php?p=2953728&postcount=442

http://www.explorerforum.com/forums/showpost.php?p=2954198&postcount=446

 

[4pointslow]

Pcv

I had to reread Dono's posts about the PCV.
If I am correct he has no vacuum pulling on the crankcase and it is just vented to a catch can. That would mean the PCV system would not cause a lean problem since the vacuum is eliminated. The removing of the PCV valve internals was for using it as a crankcase vent. Correct me if I am wrong Dono.
Do you have pictures of your crankcase vent system? We all probably would benefit from actually seeing it.
2000streetrod, what you said about the leak on one bank makes sense so there were other things out of sink. Looking at those plugs I would say it didn't happen over night, looks like an accumulation over time, but how much time, don't know.
Dono pictures of your IAC set up might be helpful too, is it stock?
And going back to the original heat range was another good idea Dono, a colder heat range makes them foul easier when things go wrong. You might need colder plugs when all is said and done but for now the stock heat range will help till the A/F tuning is done. If going to colder plugs I would install them before going into the spark timing tuning.
And when you have the plugs installed, header back on and it is up and running, I am sure me and 2000streetrod would like to see that datalog. lol.

 

[2000StreetRod]

vacuum issues

I reviewed your datalogs looking at vacuum vs engine speed. When the engine is cranking your vacuum is -32 but as soon as the engine runs the vacuum starts increasing to -11.

When engine speed is low (400 rpm) the vacuum increase rate is lower than when engine speed is normal idle (600 rpm) or above. I suspect that your turbocharger output is forcing air into your intake system that is not metered by the MAF sensor.
What is the location of the port being monitored by the vacuum/boost gauge sensor?
If you want to describe your intake system I'll gladly review it to see if I can detect potential problem sources. One reason I selected the M90 instead of turbocharging was to avoid the complications I saw in the implementation on my Volvo turbo wagon. And my Volvo had EGR deleted which made things simpler.

 

[Dono]

The iac is in stock location.
The only modifications done to the top of the motor is the catch can system.

On the 5.0 motor the pcv valve setup is strange.
stock setup:
There is 3/8" host that runs off the pcv valve to 2 locations in the upper intake, then there is a 3/8" hose that runs from the oil fill tube to the intake tube, post maf.
....closed system, makes perfect sense.

So, what to do with a rear mount turbo that when in boost, the intake tube is boosted along with everything else? There is no vacuum. Even if I were to run a line to the back before the turbo, I'd be re-metering the air since the slot maf is blow thru. A check valve can't work as the check valve will close under boost, but any leakage to the bottom end will be forced out the seals. Not good.

So, the only solution......
Catch can.
I pulled the upper intake and pcv valve system (all the 3/8" plumbing still attached to the lower intake). Then I pulled the 3/8" hoses off the lower (2), and plugged them with vacuum plugs and clamped). After that, I shaved the bottom off the pcv valve to get the one-way assembly out of it and attached a new 3/8" hose to the valve that was longer. I reinstalled the pcv valve back in the lower intake and ran the hose around to the oil fill tube and used a T to run a line in to the oil fill tube vent nipple. Then, out of the T to the catch can with a vent on the top. See attached.

Doing this does not introduce un-metered air in to the intake, and does not let the bottom end get boosted. Ideally, I would have the filter connection under vacuum.

Also, on the plugs, they looked ok before I started the tuning. This is a concern of mine. After changing the plugs I'm going to leave the wheels off along with the splash guards in case I need access to have a look at them. I hope I won't need to.

James sent me a basic tune to get started with. He is certain that taking the stock tune and just multiplying the maf multipliers by 3 (stock injectors (19lb, new injectors 60lb-----60/19=3) and setting open loop with give me a truck that will idle in its most basic form and hopefully we will get wideband readings that make sense so he can start doing his magic.

Streetrod2000, on the vacuum readings.....I beat the truck up so bad there is no telling anymore what you were seeing. I even had the starter engaged with the truck partially running at one point just trying to get any kind of a log possible. That's just how big of an issue we are dealing with. I'm certain that if the truck won't run with James new file he sent me I'll at least be able to keep a close eye on the plugs and give James some better information to deal with. Also, if Im using the slot maf, the turbo is connected. I can't use the stock maf with the turbo easily.
If required, I could pull the intake tube off after the turbo, but before the slot maf. This would remove the turbo from the equation, but I would not be pulling filtered air. Not a big deal for testing purposes.

The boost gauge vacuum is pulled directly off the upper intake with a vacuum T. When I install the 60lb injectors this weekend, I'll be opening up one of the capped off vac ports to use on the blow off valve as currently its not plumbed to vacuum. I picked up the required adapters yesterday for this.

 

[2000StreetRod]

diagrams

Don, thanks for the explanation and diagram. I'll study it before I respond.

What about the turbo lubrication system? Please post a simple box diagram showing the oil pump, turbo, oil supply and return locations.

I think you said the EGR was stock. I'm not familiar with the 5.0L but I seem to recall that the EGR valve was integral to the intake manifold on the early models and external on later models. How is the recirculated exhaust introduced into the intake system?

 

[Dono]

Cold side piping. I didn't include the filter, as we know where that is.
The piping is 2" from turbo to intercooler, then 3" thru intercooler and slot maf.
I ran 2" around the wheel well for clearance (Not ideal to keep changing sizes), then once in to the engine bay I transition as fast as I can to 3" to the maf