[RobbyBeefcake87]

Originally Posted by Tim M

So was a bit excited after reading the MAF orientation...woke up at 0545 on a Saturday to explore!

Some images:

Original as purchased alignment:



Dissection - MAF removal...appears correct:



Tube orientation...appears correct (ie not flipped end for end):



If one tried to install the MAF sensor backwards...the screws/bosses do not line up - unable. Also note the MAF connector damage (not by me!)...don't believe it to be an issue:



Updated installation dot to dot orientation...much closer to 10 o'clock:



Updated install overhead:



I disconnected the battery during this to refresh the computer (if this one does that) and took for a short drive.

Cautiously, I would say the car is smoother at low RPM (a complaint of mine) and it now performs the no-lift shifts as one expected. I can't say it worked prior (have no reason why now...). Unfortunately, my backside is not calibrated, but it does not seem to be a 12.5 second car still.

As Dave (thanks!) mentioned, we will hopefully get a couple of 1LE's on the same dyno for a comparison.

Appreciate all the assistance on this odd deal. Very impressed with the car otherwise!

Maf can't be put on backwards, only fits one way, but the maf housing tube part of the intake needs to be clocked properly to the air box.

The stock one is one piece so you can't get it wrong but most of the aftermarket ones need the maf tube to be clocked to a certain orientation. The gm and cai one have mark's on the tube and air box that need to be lined up.

Just looking at yours it looks 10 to 20 degrees off. Compare it to the image posted a few messages up comparing the gm parts guy one vs yours.

Idk if that would in anyway account for the power loss but I have been told maf orientation is important in these cars and maybe that combined with it not being calibrated correctly is the problem.

[Tim M]

RobbyBeefcake87: No argument from me. The MAF was indeed off as you mentioned - corrected and didn't seem to pick up 30-100 HP on the next drive. I wish it were that easy - still important.

[Scargoes]

Originally Posted by Tim M

I will look at the connector closer, but doubt the wiring is damaged. If a wire is defective, I would fully expect the CE light to illuminate promptly. Only CE light I've gotten is after 10+ mins on road course and after the engine loses power/misses excessively...then it will come on the next lap. The code is misfire randomly all cylinders.

When I pulled the intake apart, I was really hoping to find a rag stuffed inside when they were doing the change at the dealer...this would be much closer to what I feel...just not much poke! No such luck.

Electricial issues can present themselves in very mysterious ways. Case in point, I worked at Tesla in Engineering doing reliability and test. My model X would throw a bunch of faults at times and not function properly. Most notably during a hot humid chamber cycle. After many hours of looking and performing the wiggle test, we found the culprit, one of the connectors had gotten damaged during assembly and under the right conditions it would fail the electrical connection. There wasn't enough pin retention to allow for proper connection all the time. So when I see damage to a connector like that it throws a huge red flag to me. It is also possible that the MAF got damaged. They aren't a very robust part. And if the installer damaged the connector, it's possible they weren't too careful with the MAF either. It's just a thought based on my past experiences.

[Whocares05050]

Have you done a leakdown test yet?

[Tim M]

Whocares05050: not equipped for a leak down. Do have a compression gauge, but am hesitant doing so. No oil useage, no residue on the rear of the car, no discernible smoke. What is the spec for an LT1?

Car will be dynoed again tomorrow hopefully with another 1LE for direct comparison.

Thanks.

[Whocares05050]

Originally Posted by Tim M

Whocares05050: not equipped for a leak down. Do have a compression gauge, but am hesitant doing so. No oil useage, no residue on the rear of the car, no discernible smoke. What is the spec for an LT1?

Car will be dynoed again tomorrow hopefully with another 1LE for direct comparison.

Thanks.

Then you need to do at least the compression check. Dont bother looking up the number. You WILL know right away if one says 180 and the other says 120 lol

[GuywithL86]

Originally Posted by Whocares05050

Then you need to do at least the compression check. Dont bother looking up the number. You WILL know right away if one says 180 and the other says 120 lol

Never heard of cylinder getting extremely low compression without other symptoms.


His power loss is huge, surely if it failed enough to cause that low of power he'd have other symptoms

[GuywithL86]

ok so you have reduced power but are not setting any codes, there are not many things that would not set off the CEL.

I'm thinking it's some sort of blockage in the exhaust or intake.

Do you have NPP? maybe the NPP valves aren't opening up? I suppose you could hear that though.

Maybe try disconnecting your exhaust as close to the headers as possible and try a pull to eliminate a blockage? For all you know someone shoved something in your exhaust.


Also maybe try disconnecting your air filter, who knows maybe some idiot sprayed it with something they shouldn't have.

Maybe your cats are clogged?

Also you should be able to tell if your intake path is blocked somehow by a WOT vacuum reading. Sometimes intakes are tested that way. Less vacuum = more flow.


Torque app with bluetooth dongle would be helpful. You can read all the sensors. Could be something as simple as a fuel filter, but I'd think you'd get codes if that were the case.

[DenverTaco07]

Sorry you are having to deal with this, certainly does appear you have a dud. How did you verify the tune was correct? If the dealer installed it that IMO is a huge red flag just because dealerships, by in large, suck.

Can the shop you are Dyno'd at re-tune it?

[DenverTaco07]

Originally Posted by GuywithL86

ok so you have reduced power but are not setting any codes, there are not many things that would not set off the CEL.

I'm thinking it's some sort of blockage in the exhaust or intake.

Do you have NPP? maybe the NPP valves aren't opening up? I suppose you could hear that though.

Maybe try disconnecting your exhaust as close to the headers as possible and try a pull to eliminate a blockage? For all you know someone shoved something in your exhaust.


Also maybe try disconnecting your air filter, who knows maybe some idiot sprayed it with something they shouldn't have.

Maybe your cats are clogged?

Also you should be able to tell if your intake path is blocked somehow by a WOT vacuum reading. Sometimes intakes are tested that way. Less vacuum = more flow.


Torque app with bluetooth dongle would be helpful. You can read all the sensors. Could be something as simple as a fuel filter, but I'd think you'd get codes if that were the case.

I think if the tune is bad, it would also not throw a code, because after all, it would be doing what the bad tune is telling it to do.

[Dave-ROR]

Originally Posted by DenverTaco07

I think if the tune is bad, it would also not throw a code, because after all, it would be doing what the bad tune is telling it to do.

It's the official GM tune for the intake. Probably not that easy to screw up.

[Boost Creep]

Originally Posted by Dave-ROR

It's the official GM tune for the intake. Probably not that easy to screw up.

Yeah.
It's either a go or no go situation.
Stock tune or CAI tune.
You really can't half ass a reflash.

[Scargoes]

I'm sticking by my previous mention, This is an electrical problem. Damage to wiring, sloppy CAI install, AFR on dyno sheet is wonky (18:1 from 3-4 k rpm then slowly climbing to about 11:1 at 6100 rpm). The three things I'd verify first are that the proper tune was installed with the CAI(GM did say that the change in MAF location effects the vehicle and needs a new tune), make sure the wires in the connector are not damaged and check the terminals in the connector to make sure they aren't deformed, Check the MAF with a known good one if possible.

A plugged cat, unless it's a secondary cat, should set off a MIL. I don't think a plugged cat nor low compression would make the AFR vary so drastically and in the exact same pattern for 3 dyno pulls.

[Raven87]