Target idle.

[jameslleary]

Thats the injectors, and i Think this iPad mic is real sensitive. I have checked for vacuum leaks, both above, and under the manifold.
I do have the injector pod spacer, and the injectors are a little louder since installing it.
I have the stock regulator on it right now, the adjustable one wouldnt go much below 12psi.

[jameslleary]

Seems like the second it gets a vss signal, everythings goes tits up at the next stop.

[jameslleary]

Ready to tear my hair out. Going to pull the intake today and physically confirm no vac leaks. Im glad this is not my old tpi setup.

[EagleMark]

Maybe try no VSS first? Or just disconnect it and let the Error code go... I've never heard of this issue but if you have decent idle until VSS signal it may not be a vacuum leak? Intake manifold gaskets usually don't go bad (unless you use Death Cool) or replaced them with a glitch...

Also never heard injectors make that much noise? Does the spray pattern look OK or drippy? May have the O ring and metal ring in wrong?

[jameslleary]

Hmm...interesting. Ya know, I am using the 86 vss that is on the backside of the cluster. The Optical part itself is mounted behind the speedo, but I have the VSS wire for the ECM connected to the output located at the output that is on a separate box that is wired to the optical unit.
Putting the socket wrench down to consult diagrams again.Spray pattern looks good.

[EagleMark]

That would be the DRAC. Have you ever logged data or used a Scantool to see what the MPH is?

[jameslleary]

Cant go without vss....I have a 700r4.

[jameslleary]

Speedo is about 1 or 2 mph slow, compaired to when logging.
Beginning to think I have an internal mechanical issue, Or, The dealership installed a 305 instead of a 350 back in 2001...the side of the block has 388 cast in the side, and the back deck says 5.7. i dunno what gives.
Heres another video. I did manage to get the flashlight in the right spot for a brief moment. This is a different set of injectors I had installed after the last video...still seem as noisy. Injector spacer, and cfm-tech super sucker have been removed until this problem is solved.

Video: http://i144.photobucket.com/albums/r...y/b3b29a93.mp4

[EagleMark]

Cant go without vss....I have a 700r4.

To check idle and driveability you can.

What chip are you running with a large cap HEI? Spark latency is differant by as much as 11 degrees between the 2. Both will be 0 with timing wire disconnected, wonder what your connected timing is at idle?

Running EFI wiring next to or touching spark plug wires is a non-no... that must be a conversion?

I wonder if it makes a difference whick side injectors are on since they are both same colors?

Didn't sound near as noisy.

Did we ever look at your data log? 5.7L injectors in a 5.0L would cause issues? Wish I could be more help...

[jameslleary]

To check idle and driveability you can.

What chip are you running with a large cap HEI? Spark latency is differant by as much as 11 degrees between the 2. Both will be 0 with timing wire disconnected, wonder what your connected timing is at idle?

Running EFI wiring next to or touching spark plug wires is a non-no... that must be a conversion?

I wonder if it makes a difference whick side injectors are on since they are both same colors?

Didn't sound near as noisy.

Did we ever look at your data log? 5.7L injectors in a 5.0L would cause issues? Wish I could be more help...

I am running ARJU.
The large cap HEI is an Early TPI corvette Dizzy, which also was on the original CCC system that the truck came with from the factory.
Yes, it is a conversion from SD TPI.
Yes I posted a rich log, BLM constantly in the neighborhood of 115.
I had Idle problems with TPI too, and through the tuning process, I wiped out the required dual Cats...which was the last straw, and helped push the decision to Step back to TBI.
Just cant catch a break, It seems like this engine was doomed from the get go.
I know I dont have any head issues, it has new 193 heads.
I do have a comp 12-388-4 cam, which was suggested to me by S&P for the TPI, but is also listed as ok for TBI.
At the point now where I am sorry I even got rid of the CCC setup....been keeping my ear to the ground for a harness and carb to put it back the way it was. I Love EFI, but with the money I have thrown at this, trying to figure out the crappy driveability issues, I could have a new GM Crate Engine.
The injector plugs have been replaced, the moron that I got the harness from, cut the originals off. The green and white wires are going to the drivers side, per all of the virgin TBI trucks I have seen.
I have tried to switch them, and i do notice rougher running.
Might throw the 5.0 injectors in there, just to see what happens.

[EagleMark]

That really sucks! Now if you had issues with TPI and now TBI, what was the same in both? Looks like a nice Suburban, mine has been great with TBI from factory, never an issue, more of a test bed... and family rig.

Can you put a vacuum gauge on it at idle? What is it reading? Steady?

[jameslleary]

Yeah, Its a nice truck.
At this point, I just wish I never swapped out the CC Qjet.
Vacuum is rock solid in park at 19, and in drive at 17..... until it starts surging.
The issue was mostly idle on the tpi, and getting it tuned right for the truck so it wouldnt detonate.
The successful people (Person, Fast305)on the boards are not to quick to help out or answer questions, I am glad thise forum started up.
TBI is just Idle problems.
As far as the Minimum Air proceedure, there ar so many different versions out there. On even says to pull the est, and put it in drive to set.
I want to know what they do at the factory. I have stopped adjusting the TPS to .54...they dont do it at GM, and I shouldnt have to do it just to get it to run right.
I have seen some tps voltages as high as .71, and the truck runs like a Cadillac.
And it has a bad effect on my WOT voltage.

[EagleMark]

What about charging voltage at idle? Is it steady or declining? Declining is a common issue in conversions as they draw more juice with less altenator.

I've never had an issue with TPS voltage over .54 up to .80 but have been tols at 1.0 volt it is an issue.

Factory did not do min air. TBI was new and set. When they wear or get rebuilt or used on foriegn engine they need to be done. I have my own way that takes into account all the things you have read, but bottom line is an IAC count of 20 to 40 CL warmed up idle.

Check your timing with a dailback light and see where it is at idle. I'm really thinking the large cap HEI if running a small cap EFI chip could be way off.

[jameslleary]

Ok, I will check the timing with my snap on advance light tomorrow. I think you may be on to something with the distributor. My distributor is the only thing that is different about my conversion, vs the 40 something other conversions that I have done, which have been totally trouble free.
So for now, could I set the idle using The idle counts on the TPRT dash, and set it so the idle counts are 20....seeing as this engine seems to run better with the blades open farther?

[EagleMark]

I think you may be on to something with the distributor. My distributor is the only thing that is different about my conversion, vs the 40 something other conversions that I have done, which have been totally trouble free.

And there's your sign!

So for now, could I set the idle using The idle counts on the TPRT dash, and set it so the idle counts are 20....seeing as this engine seems to run better with the blades open farther?

I to think they run better open further but have to leave a little left for IAC to control idle. I really like to do this totoally warmed up and driven a little, then idle and look at IAC counts, if 20ish then good. If high then open up blades 1/4 to 1/2 turn and turn engine off for 30 seconds, restart at idle then rev engine for 30 seconds, goes CL and let idle, check IAC counts.