INNOVATE DLG1 Wideband O2 Oxygen Sensor Tuning Diagnostics Logging Air Fuel Ratio etc

[Gregski]

thought I would share what the laptop now looks like with the four virtual gauges, now that the Vacuum/Boost gauge added both the RPM gauge and the Vacuum gauge

check it out, now we are getting somewhere

now ideally I would want two more gauges for a total of six, the additional two that I am after are the Speedometer, ie vehicle speed, that is important because today you can't tell if the vehicle is under load ie moving or sitting at a stop sign and me just reving it up, the second gauge I would like to add is the crank position sensor to show me my timing advance as I drive ie Part throttle on the freeway say at 70 MPH and or WOT wide open throttle (on [ahem] a test track)

Note the near perfect 14.x idle ratios and I usually pull about 18 inches of vacuum at idle so not bad

[Gregski]

So a quick update at where we are at now

Idle - 14.x excellent

Cruise - 15.x very good

WOT (Wide Open Throttle) - 12.x driver side / 10.x passenger side way too rich, not good

the 4150 conversion kit should arrive any moment now, we will see if that helps

[Gregski]

yet another book to read, this one is recommended by my favorite author Jeff Smith so it ought to be good

[Gregski]

and the Holley carburetor conversion kit finally arrived today, so excited to convert my 4160 into a 4150

[Gregski]

nothing like a clean workbench

[Gregski]

some parting shots of my 4160 carb in its 4160 form

and with the air cleaner removed for a better look

[Gregski]

and here she is on the workbench ready for disassembly

Holley 4160 Carburetor (with one metering block and one metering plate) about to be converted to a Holley 4150 with two metering blocks

[Gregski]

first we remove the rear float bowl, this exposes a metering plate and the blue metering plate gasket

[Gregski]

I have no idea why Holley decided to use those pesky clutch bit screws in the metering plate, in my opinion there was absolutely no reason for it, but they were no match for one of my smaller flat screw drivers thank god

removing the metering plate exposes the blue gasket and removing the gasket exposes the carburetor body, the main body

[Gregski]

here we take a closer look at the metering plate off of the carb

note how there are no provisions for the jets or for a power valve, what you see is what you get

[Gregski]

here we stare and compare the metering plate to the new metering block

[Gregski]

now we get ready to put it all back together

we fit the gasket on the metering plate to make sure nothing gets pinched and that it is going on the right way

[Gregski]

we screw in the jets, I decided to start out with the 65 jets and go up from there

[Gregski]

we mount the block to the body

[Gregski]

and here is our "Wanna Be" 4150 carb

[Gregski]

well something that I should have done already but I kept putting it off was checking the spark plugs

this is the passenger side - I don't know about you but they look perfect to me

from left to right: #8 - #6 - #4 - #2

[Gregski]

alright well lets take a look at the spark plugs on the driver's side

from left to right: #7 - #5 - #3 - #1

Oh my that can't be good

Check out the #5 plug the second one from the left, that be what we call carbon build up it's hard as a rock

[Will206]

Curious that its only one cylinder. Aren't deposits usually a sign of liquid (oil, fuel, antifreeze) in the combustion chamber?

If that's true, not sure how it could be fuel only on a single cylinder?

My final unfortunate guess, would be valve guides, rings, or headgasket...

[Gregski]

Originally Posted by Will206

Curious that its only one cylinder. Aren't deposits usually a sign of liquid (oil, fuel, antifreeze) in the combustion chamber?

If that's true, not sure how it could be fuel only on a single cylinder?

My final unfortunate guess, would be valve guides, rings, or headgasket...

Tell me more about rings, cause I rebuilt these L31 Vortec heads that I got off of a 1999 Suburban with only 135,000 miles on it only in March, but I did not touch the bottom end, ie my original 1974 short block. So the heads have brand new valve seals, and I lapped each and every valve for a tight seal.

I am no expert in engine lubrication so I am just wondering how likely is oil to get into the cylinder from under the piston, if that's how faulty rings would allow it in there, anything else has to come from the top right?

The headgaskets are brand new, also put on in March

[SkinnyG]

New seals on worn guides won't keep the oil out as well as new seals on new guides will. I don't recall - did you measure valve guide wear whilst it was apart?

[Gregski]

Originally Posted by SkinnyG

New seals on worn guides won't keep the oil out as well as new seals on new guides will. I don't recall - did you measure valve guide wear whilst it was apart?

Thanks, and no I did not, it was a DingleBerry rebuild / refresh

[Gregski]

So I finally got my Wide Open Throttle dialed in, aka WOT to the "new" recommended horse power Air Fuel Ratio AFRs of today, that being 13.0

Discliamer: Now I aint saying this is right, this is just a starting point that I have seen in multiple sources, Holley books, and Car Magazine articles, as well as my last dyno run and 11 AFR I was told was too rich as well, so we will start here

So my last Dyno showed that I was way too rich at WOT, and my AFR gauge confirmed it, I was running like a 11/10 driver side bank / passenger side bank

so here's the steps I went through to lean it out

I started by replacing my rear metering plate with a metering block, this allowed me to change jets instead of having to change plates

Next I set the carb to what it should have come from from the factory because my didn't [see On a Holley should the Secondary Jets be bigger than the Primary? so 64 primary jets / 69 secondary jets


-JETS - - - - - -AFR

64/69 - - - - - 12/11

64/67 - - - - - 12.2/12.2

62/67 - - - - - 12.5/12.5

62/65 - - - - - 13/13*

*had to adjust the Idle Mixture screws to richen it out some cause Idle was too lean as well as Cruise

[Gregski]

So on to the next step HESITATION upon ACCELERATION!

Gentlemen, the rig starts good, idles good, runs good, drives good, but when I goose it when I step on it, when I floor it, it does the famous Whah Whaaaaahhhhhh

We must fix it!

[Gregski]

Gentlemen I need not remind you that I ain't no expert, I am just trying to figure this out, don't get me wrong I enjoy the process and I take pictures and share it to see if maybe I can help somebody out.

So Hesitation I read can be caused by a number of things and there seems to be different types of Hesitation and it may be cured by messing with a number of things so we will try the following three, by changing them one at a time.

1. Power Valve

2. Secondary Opening Springs

3. Accelerator Pump adjustment, nozzle or cam

[Gregski]

I am going in this order as silly as it may seem to some because this is the order the parts arrived in, LOL

ordered some earlier opening power valves

7.5
8.5