- Dec 8, 2011
- 1,179
4.2 Envoy Turbo Build
- Thread starter ConeKilrAutoX
- Start date
- Dec 8, 2011
- 1,179
sure thing. its dark but this is an older pic from a few days ago with my testing intake with MAF sensor and the hose leaving the intake tube goes to the fpr. thanks for the help!
gmcman
Member
- Dec 12, 2011
- 4,656
ConeKilrAutoX said:sure thing. its dark but this is an older pic from a few days ago with my testing intake with MAF sensor and the hose leaving the intake tube goes to the fpr. thanks for the help!
Is the MAF clean? From what you describe there is an abundance of fuel so check the FPR for leakage out of the vacuum port when running as well as the MAF operation.
STLtrailbSS
Member
- Dec 4, 2011
- 1,617
im pulling for you man, All i want to see is this thing idle take it to like 5000rpms and let the waste gates blow. i think we are on the right path here. Throw a post on TBSSowners some great knowledge on there as well. they know engine operation and modification. Opinions never hurt 
- Dec 8, 2011
- 1,179
I will be posting around the internet looking for all the help I can haha. Where would everyone suggest connecting the fpr line? and I am going to test for a fpr gas leak tmrw. Then I will reclean the MAF and see how that goes!
I really do appreciate all the help from everyone
thank you 
It sounds like some people want this build done almost as much as me haha! waaaa pssssh!
I really do appreciate all the help from everyone
thank you It sounds like some people want this build done almost as much as me haha! waaaa pssssh!
limequat
Member
- Dec 8, 2011
- 520
gmcman said:
At idle the pulse width is going to be as low as 0.3 ms. So we need to get the scanner on it. I'll be sending one out to ConeKiller on Monday. Stock injectors are nearly maxed even before boost. You might be able to do 3-4 psi with added fuel pressure though.
limequat
Member
- Dec 8, 2011
- 520
Just thought of another test to run:
Unplug injector harness to disable them. Run the engine on starting fluid. If it cleans up, you'll know that there's something wrong with the fuel as opposed to spark. If it runs rough on starting fluid too, the problem is probably spark related.
Also the squirting of water on the exhaust runs is a quick and easy test.
Unplug injector harness to disable them. Run the engine on starting fluid. If it cleans up, you'll know that there's something wrong with the fuel as opposed to spark. If it runs rough on starting fluid too, the problem is probably spark related.
Also the squirting of water on the exhaust runs is a quick and easy test.
- Dec 8, 2011
- 1,179
Thanks man I appreciate all the help you have been. I will keep testing out the fpr, the MAP, the MAF, etc until the scanner comes in.
fpr - if you have a return style system, these typically run referenced to manifold pressure, so the vacuum line on the regulator should come straight from the manifold(behind the throttle body). Same whether you run boost or not. As I said earlier, the point is to have the injector seeing the same differential pressure between the rail and the intake all the time. This is how every boosted/non boosted vehicle with a return line has been for me and also how my supercharged 06 is setup now with an AFPR and return line. What kind of system do you have? Did you put in an aftermarket regulator?
crankcase venting - these motors are tricky, my stock 06 pulled from the crankcase directly into the intake by way of the valve cover. the valve cover breather was connected to filtered and metered air. So if you left that open to atmosphere, the engine would breathe a bunch of unmeasured air. If yours was like this stock, you will need to do some rerouting otherwise the first time you make boost you will be pumping your crankcase full of boost...not good.
Can you please describe where you have the following routed...
the vent on the intake manifold between intake ports 3 and 4? did you leave it stock? to run boost you will have to move this.
Your valve cover breather?
your throttle body EVAP line?
crankcase venting - these motors are tricky, my stock 06 pulled from the crankcase directly into the intake by way of the valve cover. the valve cover breather was connected to filtered and metered air. So if you left that open to atmosphere, the engine would breathe a bunch of unmeasured air. If yours was like this stock, you will need to do some rerouting otherwise the first time you make boost you will be pumping your crankcase full of boost...not good.
Can you please describe where you have the following routed...
the vent on the intake manifold between intake ports 3 and 4? did you leave it stock? to run boost you will have to move this.
Your valve cover breather?
your throttle body EVAP line?
gmcman
Member
- Dec 12, 2011
- 4,656
bruhaba said:
OK, so I'm confused. Factory vacuum for the FPR is ported. How should it be manifold? Just curious.
If the manifold ends up being ported, then the current routing should work being in the intake tube. ConeKiller mentioned it was in the intake, I assumed the intake manifold.
- Dec 8, 2011
- 1,179
Ok. stock fpr with vacuum line connected to a vacuum block distributer that is connected to the intake maniold via the manifold port that was under the stock intake resonator.
throttle body evap vent is hooked up stock
the crankcase vent hose I have running to an oil catch can
the breather for the crankcase is to the intake pipe post MAF and pre TB.
thanks for the help!
throttle body evap vent is hooked up stock
the crankcase vent hose I have running to an oil catch can
the breather for the crankcase is to the intake pipe post MAF and pre TB.
thanks for the help!
gmcman
Member
- Dec 12, 2011
- 4,656
ConeKilrAutoX said:
This is what I have trouble grasping, sorry if I sound so hard-headed.
bruhaba said:
Under boost I cannot really see the difference in ported vs. manifold. However in a non-boosted state, as what your running now for test purposes, how much difference is there with the FPR on manifold vacuum vs. ported vacuum? Because clearly in stock form, the FPR is running off ported vacuum as shown in the pic. The intake resonator is mounted in front of the TB.
The nipple under the FPR line is the manifold port.
Attachments
regarding the Fuel pressure regulator discussion...
I was assuming he had an aftermarket regulator. Typically to run boost you want a manifold referenced regulator. There is another option, and from what you've shown GM may have done this. I have an 06 which did not have a regulator. I added one to be able to run boost and not have a nightmare tuning it.
Bottom line, in order to be able to calculate how much fuel is flowing through an injector, you need to know pressure on both sides of the injector and the size of the injector. Here's a couple different methods.
fixed pressure differential- uses a pump that is always running full blast and a regulator that bleeds off the right amount back to the tank to keep the rail at a certain pressure above the nozzle side of the injector. So in most cases, the regulator would be set for 43 psi with no vacuum line connected. Then when you are at -12psi vacuum at idle, the rail pressure would actually show 31 psi relative to atmosphere. However the injector will still have 43 across it so the flow rate of the injector does not change. This allows the calculations for fuel flow to be a bit easier because an injector size of X will always be X.
Fixed rail pressure - this is something GM started doing (like on my 06). Several ways to do it, but on my 06 there was a regulator in the tank that keeps rail pressure at 58psi relative to atmosphere regardless of all else. Since the ecu knows the map pressure, it calculates the differential pressure across the injector and looks up the injector flow rate based off this differential. It needs a lookup table for injector flow because at idle the injectors would be running 58-12~46psi fuel pressure, but at wot they would be running the 58psi rail pressure. Injector fuel pressure = 58psi-manifold pressure
On the picture you show, it appears from the factory is was connected to as you say "ported vacuum". This likely means GM was running fixed rail pressure on the trailblazer from the factory. Only reason I can see connecting it to ported is to prevent a fire in the event that it leaks. Ported vacuum doesn't change much. I'm a little confused too. Not typical to see a regulator that is ported to anything but atmosphere. What does a manual say about fuel pressure on these model years? Anyone know?
I was assuming he had an aftermarket regulator. Typically to run boost you want a manifold referenced regulator. There is another option, and from what you've shown GM may have done this. I have an 06 which did not have a regulator. I added one to be able to run boost and not have a nightmare tuning it.
Bottom line, in order to be able to calculate how much fuel is flowing through an injector, you need to know pressure on both sides of the injector and the size of the injector. Here's a couple different methods.
fixed pressure differential- uses a pump that is always running full blast and a regulator that bleeds off the right amount back to the tank to keep the rail at a certain pressure above the nozzle side of the injector. So in most cases, the regulator would be set for 43 psi with no vacuum line connected. Then when you are at -12psi vacuum at idle, the rail pressure would actually show 31 psi relative to atmosphere. However the injector will still have 43 across it so the flow rate of the injector does not change. This allows the calculations for fuel flow to be a bit easier because an injector size of X will always be X.
Fixed rail pressure - this is something GM started doing (like on my 06). Several ways to do it, but on my 06 there was a regulator in the tank that keeps rail pressure at 58psi relative to atmosphere regardless of all else. Since the ecu knows the map pressure, it calculates the differential pressure across the injector and looks up the injector flow rate based off this differential. It needs a lookup table for injector flow because at idle the injectors would be running 58-12~46psi fuel pressure, but at wot they would be running the 58psi rail pressure. Injector fuel pressure = 58psi-manifold pressure
On the picture you show, it appears from the factory is was connected to as you say "ported vacuum". This likely means GM was running fixed rail pressure on the trailblazer from the factory. Only reason I can see connecting it to ported is to prevent a fire in the event that it leaks. Ported vacuum doesn't change much. I'm a little confused too. Not typical to see a regulator that is ported to anything but atmosphere. What does a manual say about fuel pressure on these model years? Anyone know?
ConeKilrAutoX said:
I'm confused, do you have a turbo installed? What year pcm are you running? if you do have a turbo, is your maf pre or post turbo.
Need to see your tune to go with this. If you have the fpr connected the way you have it(manifold vacuum), then the IFR (injector flow rate) table needs to be flatlined in your tune. Ask limequat if it is flatlined. If it is like mine, the table maxes out at 63.5 lb/hr, I don't know what he would have done to run 80's. Have to scale lots of other stuff to do that and it gets complicated.
Also, explain further your crankcase vent please. The side that comes out of the crankcase on the intake you have routed to a catch can, did you then plug the huge hole in the intake? What about the other side of the catch can?
Regarding the valve cover breather, we'll revisit this after you explain your crankcase venting.
- Dec 8, 2011
- 1,179
alright... the turbo is not installed yet because I wanted it to run before pumling the turbo with all the gas/soot that it has been putting out through the exhuast. once I get the engine to fire correctly I then planned on putting the turbo on.
I am using a p12 pcm and to do that I had to also use the 06 engine wiring harness and do some re wiring only on the first c1 connector.
as for the crankcase vent, I have one hose going to the oil catch can and then another hose going from the can back to the corresponding port on the intake like the normal hose is set up to do.
I am using a p12 pcm and to do that I had to also use the 06 engine wiring harness and do some re wiring only on the first c1 connector.
as for the crankcase vent, I have one hose going to the oil catch can and then another hose going from the can back to the corresponding port on the intake like the normal hose is set up to do.
- Dec 8, 2011
- 1,179
ok I will post over there too thanks lime
submitted my registration application and it doesnt like my email over there haha
submitted my registration application and it doesnt like my email over there haha
- Dec 8, 2011
- 1,179
damn sorry I was getting confused I have the catch can installed to the PVC side
View attachment 28236
not the crankcase vent ... sorry about that. the crank case vent I have hooked up to the intake pipe post MAF but pre throttle body.
View attachment 28236
not the crankcase vent ... sorry about that. the crank case vent I have hooked up to the intake pipe post MAF but pre throttle body.
Attachments
gmcman
Member
- Dec 12, 2011
- 4,656
ConeKilrAutoX said:
I'm curious as to why the crankcase vent hose wasn't kept in it's stock location? Did you use a different intake without the provision for the tube?
I don't know for sure but did all the years have the crankcase vent tube on the left side of the intake?
- Dec 8, 2011
- 1,179
gmcman said:
I had a cold air intake that move the location to a port on the intake tube
View attachment 28237
Attachments
gmcman
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- Dec 12, 2011
- 4,656
- Dec 8, 2011
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haha thanks and yes I was just trying to keep some oil residue out of the intake which seems to be working haha but now with the new issue I just have slimy gasoline so..we shall see haha
gmcman
Member
- Dec 12, 2011
- 4,656
OK, all coming together now... What's the other hose in the pic on the intake? Does this hose require manifold vacuum?
I assume the FPR hose is the FPR?
Reason I'm asking all this is the motor ran in this setup based on the earlier video you posted when you removed the A/C from the belt routing.
What's the other hose in the pic on the intake? Does this hose require manifold vacuum? I assume the FPR hose is the FPR?
Reason I'm asking all this is the motor ran in this setup based on the earlier video you posted when you removed the A/C from the belt routing.
Attachments
- Dec 8, 2011
- 1,179
gmcman said:OK, all coming together now...
I assume the FPR hose is the FPR?
Reason I'm asking all this is the motor ran in this setup based on the earlier video you posted when you removed the A/C from the belt routing.
correct ! and it ran great only had a cracked manifold but ran excellent other wise, however that was also before the p12 swap, the 80lb injector swap, and the new 06 wiring harness. That other hose went nowhere it was just capped off but I needed there because I was not provided enough plugs for the number ports on the intake pipe adapter the the FPR was connected to
gmcman
Member
- Dec 12, 2011
- 4,656
Basically trying to rule out a monster vacuum leak. Can you put a vacuum gauge on the nipple at the front of the intake and get a reading at idle? Pretty much looking like an parameter in the injector pulse so hopefully Limequat has some input on this.
All I wanted to do this spring was get rid of some crabgrass and grow a lawn this fall. Now you're really giving me the itch to burn a hole in the bank and get some HPTuners and spend a lot of money.....lol.
All I wanted to do this spring was get rid of some crabgrass and grow a lawn this fall. Now you're really giving me the itch to burn a hole in the bank and get some HPTuners and spend a lot of money.....lol.
- Dec 8, 2011
- 1,179
hahahaha well actually my boost gauge is hooked up to that port and upon starting the vacuum bounces so fast between high and low vacuum that the needle cant stabalize so theres an issue there but is that a vacuum leak or just an engine not acting stable
- Dec 8, 2011
- 1,179
yes reving keeps it fairly stable
and ( as I sent you in pm) no leak in fpr but I took map sensor out blew in it (dont have cleaner with me yet) and it actually started and ran normal for 25 seconds so im cleaning it later and trying again letting engine air out and pcm recalibrate with battery off
and ( as I sent you in pm) no leak in fpr but I took map sensor out blew in it (dont have cleaner with me yet) and it actually started and ran normal for 25 seconds so im cleaning it later and trying again letting engine air out and pcm recalibrate with battery off
gmcman
Member
- Dec 12, 2011
- 4,656
That's great, hopefully all is good.
Something else to consider is when the plugs get fuel fouled so bad they sometimes are toast. Doesn't mean they won't work but it's risky. Hopefully when you get it running you can keep it running to get everything nice and toasty. Plugs may not come back 100% but we won't know until you try.
Something else to consider is when the plugs get fuel fouled so bad they sometimes are toast. Doesn't mean they won't work but it's risky. Hopefully when you get it running you can keep it running to get everything nice and toasty. Plugs may not come back 100% but we won't know until you try.
- Dec 8, 2011
- 1,179
Ok well I cleaned the throttle body again, sprayed the MAP and the MAF and it ran aweful, but then I unplugged the MAP and it is running like 75% healthy. just still smell gas really strongly and the engine is still shaking (not as severe) so its either getting too much fuel still somehow or (more likely) not burning up some causing excess fuel. I just dont understand how so much greasy gas is getting up onto the back side of the throttlebody plate. Hopefully Jeremy can figure that out when I get the scanner and email him the scan file.
- Dec 8, 2011
- 1,179