C5X2C

Dropped it off yesterday and haven't hear anything yet. He was going to do a compression and leak down test on the cylinder still showing the misfires. I reminded him that we haven't swapped injectors yet like I thought we had. Going on about two months for this H/C upgrade.

CarsRFun

good luck.

ChiTownSS

Hopefully this isn't work from one of of the sponsers.

C5X2C

Just got off the phone with the mechanic,,,, not good!

Remember, he wanted to run in Open loop and I thought that was unnecessary with the rather mild H/C setup.

He has told me that he has done everything to diagnose a lean condition II think) on one side after the H/C upgrade, and after mucho $$$ on my part, he says it must be the headers.

He has replaced:

All Plugs (at least twice)
All Plug wires (a short while ago)
Both O2 sensors (first ones were working fine when I came in)
All Coil Packs (first one were working fine when I came in)
Injectors (with H/C upgrade)

Smoke test on intake side (enough to blow smoke out the exhaust).
Injector signal test
Compression test

All the smog equipment, Tech2, dyno and more crap than you can imagine can't determine the issue.

The car continually adds fuel to (I think) just one side. It seams like there is a mechanical issue. The car runs well when he disables the O2s. He now tells me this is the only way the car will run well, is in Open loop.

He says that he will be calling an expert again (maybe Cartek). I asked him to check the O2s again, maybe they are the wrong ones? Maybe swap sides? How would I know?

Anyone running LGM LTs, 224/228 114, AFR 205 milled .024, FAST78, stock TB, stock MAF, Vortex Ram Air in closed loop? From what I hear, is sounds impossible. Are my expectations too high?

Grimes

iTrader: (3)

if the car runs well without the O2's then it has to be something with them or related to them. Check to see if any of the wiring is burnt (on the headers) or pulled out of extensions or cut...etc. Either that or there is an exhaust leak in front of a sensor. Maybe there is an incomplete weld on the header?

jub jub

I know this is a long shot but could it be the O2 sensors are reversed. I have LG headers and the O2 sensors have to be crossed. In other words, left sensor goes to right connector and right sensor to left connector. If this is not done, you get what you've described.

The Alchemist

iTrader: (19)

Here is what I did to diagnose a leaking collector. Leave the O2s in their respective bosses and just cross the connectors. If the lean condition now moves over to the driver's side then its a true lean condition, most likely from a header leak or from a bad O2.

Next step is to switch the O2's while still criss crossing the leads. If the lean condition now follows the O2, you have a bad O2, but if the lean condition stays, you have a true lean condition and not an O2 issue.

Good luck

Mike Norris

iTrader: (10)

What jub jub just said I was about to write. If the oxygen sesnors are crossed in front, the PCM has no real idea what the engine is doing and is trying to compensate the wrong bank by adding or subtracting fuel when the opposite may be needed. Not sure that sounded right, but you get the idea. It is easy to do with the LG's also since they say to use the rear O2's and adapters. Wew generally use the fron sensors and proper extensions run to the proper sides and have had no issues. If the fuel trims are reset and cold started and it runs decent, but goes down hill when the fuel trim learn is enabled, crossed or bad oxygen sonsors are a good bet.

We had a 2004 C5 with LG's and the heaters never worked right when having the rear sensors in front and the adapters. We installed new front sensors and proper extensions and the problem went away.

On the vacuum leak side, the FAST intakes are known to have misaligned gaskets at times and need to be checked before install. Could also have an issue with valve tip height making one valve tighter pre-load wise then the others. Had a situation here where an off brand head had been repaired and the vlave tips on on hole were much higher. Put the "standard" pushrods in that were in previously and had a miss. A quick fix was to put .050" shorter pushrods on the two valves with the taller tips and "fixed" the problem. basically hung the valve open slightly causing something like a vacuum leak.

On a side note, if we, and several other folks can tune a T-REX closed loop, your setup should be fairly easy unless there is a sensor or mechanical issue. If the car is an M6 and ran fine before, it should have even ran decent on the stock tune on initial startup. At least till the fans turned on. Hope this helps.

Mike Norris

C5X2C

Thank you Grimes, Jub Jub, Alchemist and Mike! This is exactly what I have been trying to verbalize to my mechanic. It has to be something with the O2s, not the design of the headers.



I will try to tell him again to:
Check the O2s for bad wires, bad connectors or crossed connections.
Swap the O2s and see if the problem moves.

I've got my finders crossed!

C5X2C

Obviously I am required to play a more active roll in getting my car done right.

Called LGM technical support and Shawn was more than willing to try to help me out. I briefed him on the situation.



First of all, he said that there should be no need to run my configuration in Open Loop if the work was done correctly. With some confidence he told me that we will fix the issue. LGM has done many configurations without the need for Open Loop and disabling the O2s. How refreshing to finally hear a positive mindset!

I conferenced Shawn and my mechanic in together (my mechanic didn't want to call LGM about the issue). They spoke of all those LS1 Edit tuning parms that I'm not familiar with. My mechanic made his agrument that it had to be the placement of the O2s on the headers, everything else was replaced or tested. Shawn made his argument that it had to be something else wrong because they have never seen an issue like this. Shawn asked him to make sure that, the O2s wires were not crossed as they should be in the rear position, verify that they were the hotter O2s, check the two separate grounds ( I think on the headers), check the O2 fuses, check the new injectors for proper calibration.



God I hope it was one of these problems becuase I am tired of this long strange trip!

C5X2C

Checked in today. Mechanic checked for crossed O2 wires and they were not. He said he didn't have time to look at it further today and would try again tomorrow.

SMOKINV8

iTrader: (6)

This might be over simplifying things, but has he checked for a leaky injector? It isn't too tough to lift up the rails (with injectors attached) and prime the pump. If the one on that strange cylinder leaks, then there's your problem.

C5X2C

I guess "Open Loop it is".



Tried everything, what else could it be but the placement of the O2s? Checked every lead we got from LGM. Spoke with Dave at Cartek and he basically restated the facts as I heard them from my mechanic. Didn't realize that there was so much disention in the understanding of O2 placement and running closed loop. I guess that there should be different O2 sensitivity depending on the distance and configuration from the combustion. I have had it for now!

Drove it home and after stopping at a store, it stalled and idling was rough for a while. But in general it ran well. Perhpas some more tuning is in order. I really didn't think it was going to be this difficult!

Mike Norris

iTrader: (10)

No offense to the installer, but that cam and those headers do not dictate and "Open Loop" tune by any means. What happens if the idle is bumped up to 1000 or so? I have done several 23x and up duration intake cams with LG's LT's, and though I feel the sensor placement and using rear sensors is not the best, I have never had an issue with getting them to idle proper in closed loop.

jub jub's car has the 226/230 114 with LG's and AFR 205's. The only difference is he has the stock LS6 intake and you have the 78mm FAST. Have you tried putting the stock inatek back on? May have missed it in a post here, but worth a shot if not done yet. With the 224/228 it should not be this difficult as you mentioned.

Hope this gets resolved for you.

Mike Norris

C5X2C

Mike, I sure wish you were closer than Florida!

I don't really have any choices. My mechanic told me that's the way it is, and I'm spending mucho $$$ everytime I disagree and we try something else. O2s (plus labor to remove the car from the dyno), 8 Coil Packs (plus labor). LGM suggested A&A, just a 440 mile trip each way. Perhaps I need to regroup and plan strategy! Once again, I didn't think it would take me all this effort to get this mile setup straightened out!

LG Motorsports

Bingo!

Please do this first before you spend one more dime one the car.

Thanks
Lou Gigliotti LGM

orangeapeel

iTrader: (18)

25?????? that is a lot just from 1 pt.

SideStep

I am surprised that this thread was resurrected.... C5X2C, has not posted here (LS1Tech) since June last year... Were his issues ever resolved???

LG Motorsports

You are correct. This was linked from the CF site as a way to explain his problems. I thought this was recent and didn't even look at the date.

Sorry to resurect it.

LG