Project Underfunded / next phase - LSx carb'd to LSx efi

[85burb]

What color is the smoke? I could see how it would be a tune issue. Cause if you jack with the idle mix the vaccum changes. Can you see what A/F ratio it is running at?

[68GMCCustom]

color is grey/black. not heavy...but has a heavy exhaust smell. don't have a/f as using those bungs for motors O2's. added a pic after posting that shows vacuum routing.

[85burb]

Routing looks ok to me. Do you still have the vacuum pump hooked up? Maybe it is adding vacuum to the manifold?
Posted via Mobile Device

[68GMCCustom]

no pump....just an aluminum vacuum storage canister to store 1-2 pedals worth.
wish it was adding...could use10" more vacuum.

[85burb]

How much vacuum did it make with carb on it?
Posted via Mobile Device

[68GMCCustom]

don't remember exactly....over 15", enough to activate the p.b. booster.

[68GMCCustom]

well I needed info so I took it for a spin. doesn't want to idle or make vacuum....exhaust pops as you cruise along, give it some throttle and things start clearing up. I kept my foot in it a few times to let the rpm's come up and OMG!!! It likes WOT! I think it might be running in the 7's at the track now!

Looking at HP Tuners...should make for an easier to deal with efi experience.

but...at least my new 4L85e transmission is doing well!

[85burb]

I would say the hp tuner will make life a lot easyer. Maybe popping in the exhasut is jacked up timing. Cant really crappy timing affect the vacuum. Have you checked for a vacuum leak? I am happy your trans is woking good atleast.

[68GMCCustom]

No leaks...checked more then once. Got to be in the tune.
Posted via Mobile Device
Posted via Mobile Device

[68GMCCustom]

HP Tuners ordered! I think I even get it tomorrow!

[clinebarger]

68GMCCustom, Your PCV routing is making me dizzy

The Orange arrow is the crankcase VENT, Do not put manifold vaccum to this port....Route it to the air filter duct.

The white arrow.....What the hell is that.....A separator? Get rid of that.

This is a factory PCV line. You can buy one from the dealer, And hook the line straight from the manfold to the valve cover.

[68GMCCustom]

yeah......I do need to find some way to make that hose all "flow visually"

I'm no internal combustion engine engineer or anything...just a senior performance nut that has had a handful of these vehicles going back to 1999, and speaking from personal experience. Not claiming any particular "expertise" tho...just observation...but feel free to educate me.

The little thingy at the white arrow is an air/oil separator (cheap compared to some), and part of my positive crankcase ventilation. Normally I would agree with everything you're saying if it were a sbc or other and go with what the factory did....but an LSx motor wound tight will spew a little oil that gets past the baffles in the valve covers and winds up in the intake, being sucked down and burned off but not w/o causing issues. Look at how nasty the thing looks now vs when I 1st installed it. Have you ever had to clean your 5.3's throttle body because the motor won't idle right? Its been my experience that these motors need extra oil management.
As far as the orange arrow, I was just tying the right side in with the left side. I had a little K&N filter on that side (as you can see in the 2nd pic) originally, but decided to just tie the banks together thru the air/oil separator and then to the manifold.
If you know or some reason I'll have a catastrophic failure...pulling a vacuum on both sides...I can go back to the filter with that side vented. (if I can find it )





Never caught on with my LS1 powered '99 T/A, but did with my LQ4 powered '01 GMC Sierra C3 and later a 5.3 in an '04 Yukon...and wound up cleaning the throttle body every 15k or so. And did the MAF too while I was at it, with MAF spray cleaner. Just spray both sides of the blade down with throttle body cleaner, and clean inside and out...turning your rag nice and black from the ?carbon? residue/buildup from sucking crap thru the from the covers.
IIRC...back when I had the money to "let the dealer handle it"...dealers were charging about $80-$100 to clean the throttle body (and MAF too?) to correct your vehicles "erratic idle". I got old and cheap and started doing it myself. Anyway.....that mess of fancy hose is an effort to keep blow-by out of my intake path.

[clinebarger]

Originally Posted by 68GMCCustom

yeah......I do need to find some way to make that hose all "flow visually"

I'm no internal combustion engine engineer or anything...just a senior performance nut that has had a handful of these vehicles going back to 1999, and speaking from personal experience. Not claiming any particular "expertise" tho...just observation...but feel free to educate me.

The little thingy at the white arrow is an air/oil separator (cheap compared to some), and part of my positive crankcase ventilation. Normally I would agree with everything you're saying if it were a sbc or other and go with what the factory did....but an LSx motor wound tight will spew a little oil that gets past the baffles in the valve covers and winds up in the intake, being sucked down and burned off but not w/o causing issues. Look at how nasty the thing looks now vs when I 1st installed it. Have you ever had to clean your 5.3's throttle body because the motor won't idle right? Its been my experience that these motors need extra oil management.
As far as the orange arrow, I was just tying the right side in with the left side. I had a little K&N filter on that side (as you can see in the 2nd pic) originally, but decided to just tie the banks together thru the air/oil separator and then to the manifold.
If you know or some reason I'll have a catastrophic failure...pulling a vacuum on both sides...I can go back to the filter with that side vented. (if I can find it )
Never caught on with my LS1 powered '99 T/A, but did with my LQ4 powered '01 GMC Sierra C3 and later a 5.3 in an '04 Yukon...and wound up cleaning the throttle body every 15k or so. And did the MAF too while I was at it, with MAF spray cleaner. Just spray both sides of the blade down with throttle body cleaner, and clean inside and out...turning your rag nice and black from the ?carbon? residue/buildup from sucking crap thru the from the covers.
IIRC...back when I had the money to "let the dealer handle it"...dealers were charging about $80-$100 to clean the throttle body (and MAF too?) to correct your vehicles "erratic idle". I got old and cheap and started doing it myself. Anyway.....that mess of fancy hose is an effort to keep blow-by out of my intake path.

I have to clean the TB on my 5.3L all the time, Yes I realize what causes it. No big deal to me.

Your PCV is not functioning when pulling vacuum on both sides, Especially at WOT when your engine isnt making manifold vacuum. Your using all your vacuum on the crankcase. The objective is to "Evacuate" the crankcase, Not to Vacuum it down. Some race application use a dedicated crankcase vacuum pump, Not for street use though.

The PCV has to draw fresh air through the vent to function properly, The vent is routed to the air intake because...again at WOT no vacuum is present, At WOT the air intake tract is a low pressure area, And will effectively "evacuate" the crankcase.

The left cover has a "orifice" in it, basically a "permanent/Fixed" PCV valve. So when you put vacuum to it....Its not just wide open to the crankcase.

The vent port on the right IS wide open, When vacuum is applied It can be considered a HUGE vacuum leak.

I agree, LS engines dont have the greatest oil control system, Its poor "Bank to Bank" breathing that causes this. Look it up, Its well documented.

Here's a PCV diagram, I know its old, But the principal applies to all gasoline engines.

[68GMCCustom]

I have had a low vacuum problem...but it was routed that way with the carb too when I didn't have a vacuum problem. I see what you're saying tho and will change the right side. Running the K&N filter on that side OK?

on another note I got my HP Tuners installed and working today...can't wait to get it dialed in with the help of my tuner. I can run scans and log files...so I can send them to him and he can send me an updated file to load. Eventually I'll hook up to our TBSS and do the same thing with it. Its nice to finally have a tool that I can use to see whats going on. Not sure if this is easier or better then a Tech2...but I think I can manage it alright.

[68GMCCustom]

1st scan......................and about to go out and install my (well, my tuner created it) 1st tune!

[clinebarger]

Originally Posted by 68GMCCustom

I have had a low vacuum problem...but it was routed that way with the carb too when I didn't have a vacuum problem. I see what you're saying tho and will change the right side. Running the K&N filter on that side OK?

on another note I got my HP Tuners installed and working today...can't wait to get it dialed in with the help of my tuner. I can run scans and log files...so I can send them to him and he can send me an updated file to load. Eventually I'll hook up to our TBSS and do the same thing with it. Its nice to finally have a tool that I can use to see whats going on. Not sure if this is easier or better then a Tech2...but I think I can manage it alright.

Sounds good,

HP Tuners or EFI Live is better for what your doing. If you were working on cars for a living, A Tech2 would be better, With all the updates Ive bought, I probably have 10K in my Tech2 Of coarse that's over a 13 year period.

Looks like its running lean, O2's at 0 volts, Long term fuel trims pegged at 24+, Was the PCV still routed the same when these reading were taken?

[68GMCCustom]

yes...that's with the pcv routing w/both heads going to the air/oil separator. rerouted now tho and MAF and O2's stay at 0....0v for O2's...and 0 lb/min MAF. Rev and they don't change.
wondering if I still have a harness issue?

[clinebarger]

Testing that is fairly easy, Unplug the 02's, Voltage should rise to around a 1/2 volt (.440 to .500 VDC), KOEO voltage should also hover around a 1/2 volt.

[68GMCCustom]

I'll check them tomorrow. Thanks!

[68GMCCustom]

well...it appears we've gotten the big issues cleared up...still have vacuum issue tho. Pulling the plugs tomorrow to see if I find what looks like a lean cylinder somewhere.

[68GMCCustom]

sorry guys. didn't have any updates as I've been down for a while with back issues. anyway...got a new drive shaft made as once I realigned my eng/trans angle recently, the d-shaft (which was too short already)...busted the rear u-joint hitting 2nd. I knew it was all off..... but as long as its been down with issues went for a #^@%*% drive anyway and broke it. Luckily the only thing that broke was being replaced anyway!

also bought some more gauges (to finish set) and a shim kit to fix my pinion angle. was to pick up my new d-shaft...but somebody shut my door that I left open (for a reason) and I overslept to pick it up! the family has been avoiding me all night!

I bought new 5" electric speedo and 5" 8k rpm tach. I'm most anxious about this gauge....a 3 3/8" dual gauge (not into the quads) for fuel level and oil pressure...



along with the matching 2 1/16" voltage and water temp gauges, takes care of the usual 6 in 5 holes, but also have a trans temp gauge and been thinking of getting fuel pressure to finish out the 7 holes...or will put an O2 gauge I ran when it was carb'd.

[gringoloco]

Been eyeing those gauges, too. Have you looked into the custom shop Autometers? Cool stuff and same price as off the shelf...
Posted via Mobile Device

[85burb]

I was getting worried you had left us. Good to see ya back. That gauge is sweet!
Posted via Mobile Device

[68GMCCustom]

The custom shop stuff is cool...but I already had 2 of this gauge design...so I just filled out the set.

Had a bad weekend. Opened up my box of shims for the rear axle (pinion angle)...and they are flat plates instead of the 2*, 4*, and 6* set I thought I had found on the net, and was purchasing thru a different company, Summit.
So I went to install my new driveshaft I just picked up....and the rear u-joint is the wrong size so it wouldn't bolt up.
The driveshaft is about the perfect length now tho.

After regrouping I pulled my dash apart to clip out the stuff that won't be used now, and re-rewire it all with the new gauges. Maybe I'll get it done by the time I re-order... and re-receive... my "re-placement" parts.

[XxCHEVYMANxX]

Just finished reading thru both threads, and WOW ! awesome build Kurt. I get lost in all the tech engine talk, but you have built one top notch truck. very cool!