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First LC1 problem and MAP Sensor Problem

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Old 02-24-2008, 12:32 PM
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Default First LC1 problem and MAP Sensor Problem

It took some cranking to get it to start this morning... and it runs like crap. Dark smoke out the tailpipe, serious backfiring when revving, overall idle is crappy lumpy at it's idling around 1500rpm. It's running pig rich, stinks like gas.

Last week I did several free air calibrations and it started to run better. Today, the LC1 through Logworks reports an AF of 18-19:1 at idle, and in Megatune, sits around 13-14:1.

That makes no sense, but it tells me there's something wrong with the LC1.
Mine is mounted far downstream near my test-pipe in the 9'oclock position, so I don't think I have any heat or placement issues... and I'm not running a heat shield.

The unit has it's own dedicated ground wire attached to the back of the block where the MS is also grounded. And the controller is routed through the shifter boot and it sits behind the radio, so it should be safe.

I searched and didn't find any similar problems. I plan to do a "full calibration" when it cools down in an hour via unplugging the controller etc. We'll see after that.

Any ideas.
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Old 02-24-2008, 12:40 PM
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did i miss the info about a bad map sensor?

a bad WB will have nothing to do with the car starting or idling unless you changed your settings so that AFR Targets are active around idle rpm
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Old 02-24-2008, 12:40 PM
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Are you removing the sensor when doing the calibration?
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Old 02-24-2008, 12:44 PM
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Affirm, removing the sensor and airing out the garage before performing.

Sorry about forgetting the MAP sensor issue. If I push the hose all the way in through the case, the sensor will not read. I've gotta make sure the hose is forced as far as it will go... or push it all the way on, and pull it back 1/2mm. It's showing good vaccum, but I think I may have to open the case and make sure the wires are still good on it.

Paul, that's interesting... I'll admit my knowledge of MS software is still in it's infancy.
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Old 02-24-2008, 01:28 PM
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there is a small piece of hose that connects the fitting mounted to the case of the MS to the actual map sensor. i recently had my MSI apart and found that that piece of hose was a lil loose for the map sensor. since i didn't have another piece of vacuum hose with a smaller ID i cut a small piece of heat shrink and shrunk it onto the map sensor fitting so as to build it up a bit. then slid(forced) the hose piece over that. problem solved.

you can always try a very small zip tie or something to squeeze it on tight.

the symptoms i was having was when i would move the vacuum hose a bit the car would stall. it was enough to allow that piece to leak..
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Old 02-24-2008, 01:32 PM
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Just "full calibrated" the LC1. It's still showing at leat 2 full points higher in Logworks than Megatune.
I couldn't get it to start at all this time.
I unclipped and re-seated the MAP sensor and it's "sensing" fine now as far as I can tell while cranking.

Can I email someone my MSQ to take a look at? I haven't made a single change to it except some of the EBC table numbers. It should be exactly as Brain sent it to me except for the Dwell and maybe one more thing he told me to change.

Send me email if you would like to look at it.
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Old 02-24-2008, 01:32 PM
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When you say the sensor will not read are you saying that you get ZERO reading on the map sensor or it defaults to atmospheric pressure like 96 kpa or w/e it is for you.
The target AFRs are not followed during warmup, everything is based on your WUE tables.
There are two failure points for the "wiring" on the map sensor. The large metal pins could be loose in the map sensor which means the sensor is scrap now or the pins might have a cold joint or something in the actual circuit board. Though both of those are highly doubtful. The two screws holding the map sensor to the circuit board should keep the pins from breaking like that.

One thing to try. Get yourself a union for that vacuum line. cut a 3-5" piece of vacuum line. with the MS out of it's case, but with the endplate still on the mapsensor install that piece of tubing. Then use a small ziptie around the nipple on the MAP sensor to keep things cherry there. Then never touch that part again.
Use the union as a "bulkhead" style setup without the actual mounting bracket that way you know you're not tweaking the mapsensor itself everytime you install uninstall.
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Old 02-24-2008, 01:37 PM
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note: i have mapdaddy sensor so yours may be different.
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Old 02-24-2008, 03:01 PM
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You have a set up issue. Both MT and MLV need to be configured *independently* for wideband.

There is no way that it is an actual issue with the LC-1.
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Old 02-24-2008, 03:02 PM
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Map sensor reads perfectly now, thanks for all the info.

So, if my LC1 isn't the cause of the car not starting properly, it must be something in the software. Either I accidentally clicked a value I shouldn't have or enabled an improper function. I've looked through all the MS manuals and it's just not written in my language.

CRAP! I'm looking at the gauges as it's cranking and everythng seems normal except the AF which is down in the 6-8:1 range.
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Old 02-24-2008, 03:04 PM
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Reload a known good MSQ sam. Or, double check your cranking PWs. Maybe something got corrupted there.
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Old 02-24-2008, 03:11 PM
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Agreed Ben. I just went into C:/ProgramFiles/MS/Car1/mtCfg/settings and made sure it was set to LC1 0-5v 10-20:1. Correct.

When I first got the MS, I saved the orginal MSQ that was on it. Unfortunately it's on my wifes Dell and the battery is dead. And the dog (I am not making this up) ate through the power cord yesterday. I think BB sells Dell's now, so I might be making a trip down there later to grab a new power cord.

I will check the cranking pulsewidths as well when I reload the new MSQ.

Whatever I do, I've gotta do it quick, cause the race is gonna start and then I'll be done for the day!

Thanks Guys!
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Old 02-24-2008, 04:03 PM
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I just uploaded a new MSQ.
It was the MSQ that was in place for the first time start of the "new motor". I saved it immediately after I'd set the timing.

If you listen closely, you can hear it down in the garage purring like a baby tiger cub. It just sounds too mean to be a kitten! Now to go see if the EBC works!

Thanks Guys!!!
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