Bill Ball

Note the analog out on the LC-1 is not without its problems. However, I think the major problem has been failure when driven out of range, not inaccuracies per se. Yet, you may want to redo the LC-1 grounds per Andrew's remarks. You may want to repeat the free-air calibration of the sensor.

Bill Ball

Andrew/John: Regarding the analog out settings for the LC-1. I just left mine default. Is that right? It looked right to me.

David L. Lutz

Any comments here?

I too worked all day trying to track down leaks and after finding and fixing a couple of small tiny ones, I still have some leakage down under (way down) the intake.
I believe one source is also the throttle body linkage so. . . on a supercharged car would this tiny amount of air make for an unstable idle?

The engine on my car is currently idleing at 650-700rpm but is a tad rough. Not really all that much variation in RPM, its more like a miss and then it catches up.

One other symptom I notice is in netural if I really punch it hard (up to 4500rpm) and let off fast the engine almost dies?

Any thoughts or suggestions would help. Or should I be checking something else before I remove the intake for the 2nd time.

Sorry Craig, I don't mean to hijack but thought our cures might be related.

aggravation

Hi David, no problem, the more meat we throw on the table the more people show up to help...

I talked to Tim, actually he called me before I got around to seeking his advice, talk about excellent customer service!
Anyway, one of the things we discussed was my leak where the throttle plate shaft penetrates the throttle body at the the cable linkage....he thinks that is not enough of a leak to cause my symptoms and suggested I keep looking before taking the intake out just to fix something that probably isn't the source of my problem. He told me about using a plastic tube to listen down below the intake while it's pressurized to be able to pinpoint the leaks. I was using a fancy ultrsonic leak detector but it was too sensitive to narrow the location down all it really did was amplify the sound under the intake so loud that all sense of direction was washed out....sometimes low-tech trumps high-tech!

On that stalling after accelerating, mine did that a while back but it turned out to be the ISV....you just replaced yours though didn't you? Mine was fixed at that time with a dose of WD-40 down the large vacuum line on the driver side that goes to the Y fitting on the boot under the MAF. Of course I just finished replacing my ISV last week and the inside of it was kind of gummed up, possibly the result of that WD-40, so anyone using that method be forewarned it may be a temporary fix....

John Speake

The LH ECU in the 928 from MY87 does have an adaptation software routine, although it is fairly mild. Car runs pretty well from a battery disconnect, improves over the next 10 miles or so.

In the PEM version of the SharkTuner software we have included the option of switching adaptation off while SharkTuning, as it can "fight" with Autotuning of the LH under some conditions.

John Speake

Hello Bill,
No, you need to change the Analog 2 (WBO2) output law of the LC-1.

See Page 7 of the LH2.3 SharkTuner User manual, available for download on my website, and also the LC-1 manual, section 6.5, page 14.

Bill Ball

Argh! I saw that page but misunderstood it (reading too quickly). Try again.

Also, the 3mm jack lead you provide does not fit the LC-1 output cable. The LC-1 output is 2.5mm and I think yours is actually 3.5mm.

Thanks,

John Speake

Hello Jim,
OK, when all else fails, read the manual :-)

The 3.5mm jack plug is for the LM-1 output, not the LC-1 (those LC-1 jacks are for calibration, data etc)

The LC-1 NB and WB outputs are on the flying leads.

You need to connect the WBO2 output from the LC-1 (the Brown wire) as shown in the diagram I sent Jim with the ST.

If you want a copy of that, please email me via my website, and I will send you a scan of that sheet as an attachment.

Bill Ball

OK, before I get myself into more trouble, I should probably get some sleep. HOWEVER, I understood as you said that analog 2 is the brown wire and that ST needed analog 2. BUT for some reason we made a 3.5 to 2.5mm adapter and plugged the ST into the LC-1 output cable and it worked. The AFR readings in ST were what we saw when we had the LC-1 hooked to my laptop. Strange. I'm going to sleep it off. Maybe I imagined that Jim and I did this and drove around tuning my car a couple of days ago. Either that or Alzheimer's disease is a lot more fun than I thought it would be.

John Speake

Hi Bill
The 2.5mm flying lead of the LC-1 connects to the displays like XD-16, but I don't know what the data on that line looks like.

It is best that you use the Brown wire Analog 2 WBO2 signal.

David L. Lutz

Listening with a plastic tube is how I found the other 2 small leaks. I does work very well but I still can't seem to pin point the other one under the intake.

Yes, my ISV is brand new, flappy bearings etc. new, etc. I am wondering if I have some leakage either where the throttle body bolts on the manifold or where the manifold joins the heads. I will keep looking.

aggravation

I wondered about the gaskets that came to seal the throttle body to the manifold, on one side there was a bead of plastic feeling material that I assumed was designed to spread out to help seal however it had two voids where the bead wasn't continuous. It looked like it might create a gap if it didn't spread far enough to connect the two ends of the bead.

I probably should have asked someone but I put a thin layer of red RTV on both sides of the gasket and bolted it up, I think I put the side with the extra material facing the manifold.
It makes me wonder what the heck that bead of material was and if I screwed up by adding the RTV....

David L. Lutz

Thats a good question? I didn't use any sealant on that gasket. Also on some of the hoses "down under" like on the ISV I even used clamps where when I removed the intake there were none!

Again my real question is (which Tim advised you on) is how much leakage will give us the problems we are having. My intake holds pressure for over a minute and you really can't hear the leak until its under at least 7 psi or so.

Jim Morton

No worries John. The WBO2 was connected correctly on Bill's car using the brown output wire. I cannot speak to the free air calibration, but the signal into ST was correct. I would not have gone out on the cruise runs without things correct.

Ever thought of hosting a blog site called "Dear John" ???

John Speake

LOL ! No, I am busy enough already :-)

Are those Sharks in the waters surrounding that boat ?

So Bill just needs to calibrate the WBO2 output on Analog 2 of his LC-1.

The version of ST software you have also allows you to edit "WB law" in the "Tools" menu. He could do the change it that way.

But then you would need to remember to edit it back when you use it with your TechEdge WB unit.

So safer for Bill to reset his LC-1 Analog 2 output.