miatauser884

iTrader: (11)

With two people having the same problem, I would suspect signal. Then again, it could just be coincidence.

Could a bunk spark signal on one COP cause this. Any chance that the big *** capacitors are causing problems?

Tony the Tiger

iTrader: (4)

Hey Scott sorry to butt in, but I have some stock blue tops from a 1.6 that were just removed and working, that Id ship ya for the shipping cost if it would help.

Braineack

iTrader: (62)

I pulled the MS out last night and tested the fuel injector outputs. They are consistent with one another. I'll need to put it in injector test mode today and see what they sound like indivdually when the car is not running. I can easily swap #4 with #3 and see if there's a change. If an injector was leaking I could sort of see this issue being the cause, but it really doesn't explain my MAP readings.


unless the capacitor blew, doubtful. I need to check the voltage rating of mine, I remember it being rated at 50V.

I'll PM you when/if I'm ready to take you up on that offer.

Braineack

iTrader: (62)

The cap I have installed is rated at 16V. I know I went over that, I saw voltage reach 21.5v on the MS, but it doesn't look compromised/exploded. I guess I could try removing it and seeing what effect that has.

Braineack

iTrader: (62)

so phail.

tried running batch mode. lol barely could even idle.

look at my log, check out the vacuum spikes. I can't believe I'm at such a loss. Its so damn sensitive to the pulse width but the GVE is fairly stable. Also notice it's averaging stoich during the first part of the log, then starts averaging low 13s at the same pw near the end.

Braineack

iTrader: (62)

Blah. I wish I knew what the issue was.

Those vacuum spikes appear to be misfires when I'm idling...I don't see them register on my dash gauge, but it happens within TS for sure. The MAP decel enrichments then pull fuel and the car gets upset.

I guess I should try different coils and double chek the TB for a 3rd time. I just cant fathom the HG at this point. I think it's something to do with ignition, be it a weak spark or improperly timed, or the TB is slightly off.

Driving around town there's really no issue, I have been still DDing it for the last 4 weeks during this issue. There's a noticable delay between my enrichments and when the car actual reacts to the pedal, so my throttle repsonse is dick at best. it idles rough like its out of balance or I installed stiffer motor mounts. It misses at idle like seen in the logs above. and the AFRs show rich at idle.

miatauser884

iTrader: (11)

Have you tried playing with the COP dwell time. I know that we are running the calculated ideal, but maybe it needs to be a little longer than the 2.3ms. I've always wondered if the capacitors can have an impact on the required dwell time. What would you adjust at the TB. The amount that it is open when the throttle is closed.

Braineack

iTrader: (62)

Cap is fine. Ive had those cops running the same dwell for years now, ~2.1ms running. I pushed it up to 3-4ms at idle to see if there was any noticeable change; none to speak of.

miatauser884

iTrader: (11)

I wonder how sensitive the COPs are to heat. I have some spare COPs, I might try cycling one of them through and see if I notice a change. I wonder what the odds are that more than one COP is weak. Does yours miss consistently? Could you time between the misses to see if there is a pattern?

Braineack

iTrader: (62)

Keep in mind, I've had these coils fit since sometime in 2007. The only thing I would blame would be a bad coil in one or more.

and you can look at my log, it's really not consistent. Seems to happen most the warmer the AITs.

You can see in the log the car is hyper-sensitive to fueling, a .050% change in PW makes a significant change in the AFR, but at the same time you can also see the GVE is fairly solid.

If anything you can clearly see the engine speed/AFR/MAP is like a sin-wave. That's not normal.


I thought I had a spare coil floating around but couldnt find it. I wanted to try it on #2, the clyinder that had a plug that looked different from the rest.

Actually IIRC, that's the cylinder I had a replacement coil on. I burnt out the tach out on one last year, so it it might have a bad history and now is compromised? I really dunno.

y8s

iTrader: (8)

sinusoidal oscillations in the MAP/AFR/RPM are very normal... when your idle mixture isn't perfect.

Braineack

iTrader: (62)

can post pics later, but I have 19 teeth between my pully marks.

when set to TDC the intake cam appears to be slightly advanced, the E mark rotating slightly past the nub.

When I rotate the cams as close as I can to center the nubs to the cam marks, the crank appears to be closer to 2°.


even if it's off 2° at the crank that shouldn't cause the issue, I'm just running a static advance over my base timing that I think I'm running in MS, correct?

I put my #2 coil on #1 and I'll look at the plug when I get home, if the ceramic has started to turn yellow, maybe it is in need of replacement.

miatauser884

iTrader: (11)

The problem is that it idles perfectly, and then something throws it into chaos. If my MAP value changes from 32kpa to 34kpa at idle, this will send it into fits. I can't imagine that idle should have that narrow of a window for remaining stable. This may be the perfect time for me to use tableswitching and make a really high resolution idle map, and then let it autotune. I think that this will be a bandaid and there is an underlying problem.

Did you try the radiator pellets?

Maybe I need to start from scratch and retune my idle mechanically (adjust TB) then adjust PID. Maybe the code changes are enough to warrant more than adjusting the PID algorithm. I think someone wrote up a good set of instructions recently.

Braineack

iTrader: (62)

yes, I tired some stop leak. nothing to report on that.

Same issue will occur on my car with the IAC diabled, spark advance locked, fueling table set to a static VE% and all enrichments disabled. Once I start leaning it out past ~14.0:1 it goes to ****. the vacuum drops off suddenly and goes into a tailspin. Richen the mixture back up and everything stablizes on its own. Hypersenesitve to AFRs but only stable below 13.0:1.

I've always been acustomed to a perfectly smooth and stable idle, while also having imperfect AFRs, varying idle PWN%, and wondering spark angles.

It happens on both sets of injectors so I can't blame them. So I gotta assume the fueling is okay. Currently my PW at idle is exactly where I typically would see 14.5:1 at idle. I'm around 1.75ms at 900RPM. Since the issue started, I'm fueling at 11.9:1 at that same pulsewitdh once warm.

Assuming my AFR gauge isn't lying to me (AFRs are typical when driving, it starts to hesistate at 16.5:1 in cruise like normal) what would cause the lack of air? bad crank/cam timing..but I'm pretty sure I'm okay there.

The HG thing could still be true if 1 clyinder is getting water in it. But I'm really doubting that lately. But the addition of water to the mixture...would that not lean up the reading? or would it eat at some oxygen present in the exhaust?

The coils could be to blame if 1 or more is weak...assuming I'm getting very poor burn, that could allow for raw gas to be unburned.

Both the above could cause my enrichment issue, having a clyinder that's underperforming. But the car sounds healthly, does not have a 3-cly feel. If I pull any 1 injector or coil there's a noticable change in idle quality.

BLAH...fwiw, my idle screw is maxed. I cannot lower the idle speed any further mechanically. I had to lower it a full 360° to still hit my 850RPM idle target when this issue first happened. That made me first think vacuum leak, but like I said, I can't find one.

The only thing I can think of is that I did fit a 255HP pump before/during the issue. Everything was fine for maybe 2-3 weeks running on it. When I first noticed the issue and started diagnosing, it was when I fit the 240cc injectors and installed an adjustable fpr that I noticed my fuel pressures weere inconsisent. I blamed it on the FPR being a used cheapo ebay unit, but I'm wondering if the fuel pressures are jacked? I could only see this causing the issue if say the pressure were at something like 80psi at idle, and even then, the car shouldn't hesistate with throttle input like it does.

im honestly out of ideas. :(

miatauser884

iTrader: (11)

Any headwork???

Braineack

iTrader: (62)

yes, a little diy headwork done years ago. head also has new valve seals that were installed last summer.

miatauser884

iTrader: (11)

Just wondering if changing head flow could cause this, but it seems unlikely. Is it possible to tunr the car too well, i.e. it becomes too sensitive to changes in the surroundings? What happens if you lower your MAP averaging value to something like 20? This causes it to not sample as many points correct, consequently averaging out random spikes???

Braineack

iTrader: (62)

I've had my map sampling at the deafults for the longest time. so 45° over all rpms. Served me fine for over a year. I changed them to match what y8s had on his to see if that would make a difference.

I don't believe this is anything MS related. like I said, I could barely even idle the car in batch mode...thank god im seq. while this issue is happening.

Braineack

iTrader: (62)

you can see what I'm saying about the intake cam looking slightly advanced, but the 19 teeth between the marks says the cams are aligned. this is when my crank pulley is set to exactly TDC.

If i rotate the intake cam slightly so the marks on both pulley are equal with each other, the crank pulley sits at 2°.

So if anything my crank pulley *might* be off, but it's ~2° if that's the case...and that's just static timing.

wouldn't that be the same as bumping my trigger angle back up to compenstate? am i right? or it that still enough to maybe cause my issue?

miatauser884

iTrader: (11)

The top pic looks like mine. E not quite on the tooth, and I matches the tooth. Bottom pic makes it look like intake side is off a tooth.