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Old 05-24-2011, 03:20 PM   #41
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throw in your narrowband if you have one to check at idle where its at.
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Old 05-24-2011, 03:23 PM   #42
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it's installed, just need to hook it up and read the voltage.
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Old 05-24-2011, 05:48 PM   #43
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I loaded an older good map, and the enrichments are just awful. I had been running without EAE while I have been trying to figure this out and with my old EAE settings that I've had for over a year, the car hesitates like crazy between shifts. Worse off is after a start during ASE, I almost backed into a car because I hit the gas and the car did not move forward. I watched my vacuum gauge slowly spike to 0, then I felt the gas come on. I could repeat this while it was warming up, give it gas, watch the vacuum gauge hit atmospheric, then feel the injection. I'm running 100% TPS enrichments, so im unsure why there is such a delay? I didn't log it, and I will next chance I get, but the TP% seems to match my movements.

Other than that the car drove well, I am missing at idle from time to time, but it's less of a a miss and more of a spike in vacuum.

see log attached.

this makes me scratch my head and lean away from my bad LC1 theory.
Attached Files
File Type: msl 2011-05-24_12.48.09.msl (183.4 KB, 73 views)
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Old 05-24-2011, 08:22 PM   #44
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Just thinking out loud, could the new alternator be regulating at a different voltage than the old one.
Wouldn't that mess up not just injector times, but also dwell times to fire the coils?
There's also the possibility the LC1 controller had a hit and what it may be using as a reference voltage is now affected.
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Old 05-25-2011, 09:46 AM   #45
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When I fit the new alternator, I also redid my voltage calibration in TS, I always knew it was reading low, but I just tuned for it. I used a Fluke DMM and would see 14.6v at the battery when the megasquirt was showing 13.5v. So once I redid those calibrations, I made sure that my injector deadtime curve shifted as well, putting my 100% value at 14.5v. I also did the same with the dwell battery correction table to make sure my dwell was the same as before.

One thing to keep in mind is that this might have acurred before the alternator hit, I usually have the radio on and don't notice the idle inperfections.

I still keep coming back to the head gasket. The car acutally idles slightly leaner during warmup at the same RPM and PW. Once the motor gets to about 160-170F, I notice it gets richer, even at a slightly reduced PW, it also pulls about 2-3kPa more vacuum.

If there is a tiny HG leak into a clyinder, I could see the AFRs going rich, because the water and/or oil is taking up some of the overall mixture percentage. I could also see how it could make the car feel unbalanced and make it get upset when I lean it up because there's not enough fuel to make a complete burn.

I appear to have some sort of leak at the back of my head onto my transmission, but I think it's a very leak from the VC gasket and CAS o-ring. It's like liquidey oil. I had cleaned it off a week ago or so, and it has returned. I said earlier, I have a slow coolant leak, I topped off my overflow a few days ago and it still appears to be in the same general level, so I'd figure it would drain off more than that, and there's no bubbles or overheating of any kind. And plus my cooling system tests said everything was okay.

I have a DIYPNP I built in my car today, I'm going to swap it in at lunch and just see if I can rule the MS out all together. I've always thought it was mechanical I just can't figure out what, car drives great off idle. If I turn on the radio and ignore my AFR, besides my current shitty enrichments and weird TPS and MAP spikes, I wouldn't think there was an issue.

A few things I did forget to mention:

I had to lower my idle speed screw 1 full turn clockwise - to maintain my 850RPM idle, I was maxing my lower duty cycle limit for my idle valve. I haven't touched that screw in over 2 years. This is when it first started happening and when I first started looking for a vacuum leak.

My compression showed (IIRC) 185 - 180 - 185 - 190

plugs always look coated with a white flakey coating on the electrode, ceramic looks clean.
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Old 05-25-2011, 11:20 AM   #46
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Quote:
Originally Posted by Braineack View Post
When I fit the new alternator, I also redid my voltage calibration in TS, I always knew it was reading low, but I just tuned for it. I used a Fluke DMM and would see 14.6v at the battery when the megasquirt was showing 13.5v. So once I redid those calibrations, I made sure that my injector deadtime curve shifted as well, putting my 100% value at 14.5v. I also did the same with the dwell battery correction table to make sure my dwell was the same as before.
This is wrong because there is a significant voltage drop from the battery to the ECU and the injectors. You need to attach the black probe on the ECU ground in the engine bay, and measure the voltage at 1B.
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Old 05-25-2011, 11:36 AM   #47
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can do. But even if I did recalibrate and then shift all the things effected by voltage, wouldn't it not matter?
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Old 05-25-2011, 02:14 PM   #48
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i reset it back.

At first I was about to hit myself as during warmup it was reporting leaner at 14.5:1.

as the warmup enrichments decreased, the AFRs were acutally increasing. at 123% gammae i was watching it maintain at choppy 14.5:1 idle, 1.8-2.0ms PW, 36-38kPa vacuum.

at 160*F and 100% gammae, the afrs dropped to 13.5:1, 1.8ms PW, 35-36kPa.

at 180*f and 100% gammae, the AFRs dropped to 11.9-12.2:1, 1.77X-1.82Xms PW, and 33-34kPa.


my overflow looks like it was half way between the full and low marks. I had it a full on a cold motor when I filled it over the weekend.
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Old 05-25-2011, 09:15 PM   #49
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my 1.6 developed a tiny little crack in the HG directly above the oil supply port at the back of the motor behind cyl 4 on the hot side of the engine.
It did a very similar thing, rich idle good driveability and this was still with the stock ecu, pre turbo.
When I MS'd and installed the turbo I redid the HG and thought nothing of it.
At the time, I had no coolant loss, oil pressure seemed normal and no oil/water mixing.
But my idle with the stock ecu was always rich (only had the car 4 odd months beforehand).
The only reason i did the HG was that the back of the engine always had a light smear of oil on the gearbox housing and it wasn't coming from the VC gasket or the cas.

Would a leak down test prove a faulty HG?
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Old 05-26-2011, 09:57 AM   #50
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a leak down test would be able to prove it, i just dont have one or a compressor handy.


just to make sure im not crazy, this looks good to everyone?




I have had a head gasket fail before, it was acutally about 20 minutes into my first drive on it. it leaked coolant into #4 and the idle was rough but not like this. Then on my drive back home to figure out the issue, I started overheating and lost significant amounts of water. The liquid on the back of the head on top of the gearbox appears to be more oil than anything, but it does look diluatted, but no smell of coolant, or green hue.

I'm pretty sure I'm just going to end up replacing it soon, but I would have figured the compression test and/or cooling system pressure test would have uncovered something.
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Old 05-26-2011, 12:09 PM   #51
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you guys are haters, fix my car.
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Old 05-26-2011, 01:33 PM   #52
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what do you think of this:

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Old 05-26-2011, 01:44 PM   #53
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Can you take a baller macro shot of the electrode and insulator area?
Also, is the insulator bright white, or does it have a yellow/tan coating on it?
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Old 05-26-2011, 01:48 PM   #54
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I can when I get home. thats a cell phone pic. That's #3, pulled to look at piston tops again at lunch.

IIRC, when I changed plugs a few weeks ago #2 had a slightly yellow ceramic. Otherwise, they all looked bright white. all had the flakely white buildup.


it's just odd cause I'd think by now I'd start overheating, or then a sub-par idle quality/mixture, you wouldn't think the car had an issue. I should honestly just man-up, do the HG, and rule it out.

I think in the least this weekend I'm going to retorque my head bolts and see if there's any change.
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Old 05-26-2011, 01:55 PM   #55
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Quote:
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what do you think of this:

That looks good to me but hard to tell with that yellow hue in the picture.

FWIW, my GTX idled perfectly normal with its blown headgasket. I could lift the cap of the radiator and see the coolant gurgling. The spark plug looked completely normal and looking down through the tube it didn't look as if the piston was steam cleaned however when I took the head off the piston wiped down very easily compared to the rest so it was definitely getting steamed.

I really doubt this is a headgasket issue.
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Old 05-26-2011, 01:59 PM   #56
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acutally, I have all 4 of the ones I pulled still in my car, BRB. I'll get a better shot.

I just dunno what else to really blame at this point. I am getting slight coolant loss, but no other obvious signs.
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Old 05-26-2011, 02:05 PM   #57
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Quote:
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acutally, I have all 4 of the ones I pulled still in my car, BRB. I'll get a better shot.

I just dunno what else to really blame at this point. I am getting slight coolant loss, but no other obvious signs.
I dont know but this how my car has ALWAYS idled with my megasquirt and i must have had 3 headgaskets and 2 engines in the thing since. And again, you saw how bad my GTX gasket was and that thing idled FINE. It ran so well that a friend of mine who is a mechanic commented on how well it was running and congratulated me on my engine building skills lol. He's going to eat his words now.
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Old 05-26-2011, 02:08 PM   #58
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these are the ones I pulled maybe 4 weeks ago when the problem first started.



well...I hope they are - I might have more in my trunk.
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Old 05-26-2011, 02:11 PM   #59
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Maybe its just the picture, and this is off subject, but cant you run more gap than that with COPs?
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Old 05-26-2011, 02:14 PM   #60
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those should be at whatever gap they are out of the box. .040" IIRC.
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