hovermike

I've got my engine back together after getting the head rebuilt, new head gasket, AFPR rebuilt by Corky, coolant reroute, steel turbo oil drain line, newly rebuilt injectors, and new master clutch cylinder.

I've adjusted the on-set on the AFPR to get rid of the pinging that was occurring at 4inches vacuum ~ 4lbs of boost, but nothing will get rid of the pinging going up to 6+lbs (I've got the additional fuel pump) at 3/4 - WOT.

This is the old (now ancient) FMI setup w/ a T28, Intercooler, AFPR, and MSD Ignition retard. Here is what I'm working around:

1.) Car pulls great when cool - no pinging at any level of throttle / boost.
2.) Once warm, pinging is horrible at 3/4-WOT past 4krpm @ ~6+ lbs. I've closed the check valve on the AFPR, but the extra fuel pressure doesn't seem to be doing anything.
3.) The vacuum/boost lines appear to be good - all the additional ones are coming off a port inline w/ the brake booster line - getting good readings w/ the boost gauge.

Possible causes (looking for input here)
1.) Possible 9 year old MSD ignition retard is no longer functioning? How would I test to see if this is still working (or should I just say screw MSD - go Bipes?)
2.) Oxygen sensors are operating outside of normal range and not getting the injector pulses wide enough and causing a lean condition near WOT (though it should be at open loop at this point, shouldn't it?). I've got a scan tool coming in on Thursday that can get real-time data streams.

Really looking to get this car running w/o ping for the 8th of May for a track day at Harris Hill... don't want to worry about keeping the pedal off the floor :-)

bigwig

Get colder plugs.

budget racer

iTrader: (1)

Pull the vacuum tube off....plug your finger over the opening....blow into the tube.....watch with timing light to see if ignition timing changes.

hovermike

Thanks for the tips - have some BKR7Es on the way. Looking forward to the difference.

AlexO35

iTrader: (7)

Why don't I see anything about the WBo2 readings?
--Alex

Sparetire

What are the current plugs gapped at?

OEM HG?

levnubhin

iTrader: (30)

What are your afr's? I'm assuming you do have a WB. Also, sell all that bandaid bs and get a real ecu.
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hovermike

Ok, everything is stock as far as ECU, o2 / etc. Here's the OBDII data I've scanned off today. It looks like the MAF is not seeing the air as it should and therefore the injectors are getting too small injection pulses Here's the data. I initially accelerated from 0-65 (see load in the ~70% area. I didn't give it WOT due to pinging concerns - and man was it pinging...) The o2 sensor is going back and forth as it should... but the MAF sensor occasionally shows a very small load even though the load is high... (like 72.9% load, and 1.067 lb/min? Malfunctioning BOV?)...


Live Data
LOAD_PCT(%) 18.4
ETC(°F) 199
RPM(/min) 915
SPARKADV(°) 8
IAT(°F) 136
MAF(lb/min) 0.382
O2B1S1(V) 0.065
------------------
LOAD_PCT(%) 16.9
ETC(°F) 198
RPM(/min) 926
SPARKADV(°) 8
IAT(°F) 136
MAF(lb/min) 0.370
O2B1S1(V) 0.765
------------------
LOAD_PCT(%) 16.9
ETC(°F) 198
RPM(/min) 910
SPARKADV(°) 8
IAT(°F) 136
MAF(lb/min) 0.385
O2B1S1(V) 0.075
------------------
LOAD_PCT(%) 17.6
ETC(°F) 198
RPM(/min) 890
SPARKADV(°) 8
IAT(°F) 136
MAF(lb/min) 0.380
O2B1S1(V) 0.105
------------------
LOAD_PCT(%) 17.3
ETC(°F) 198
RPM(/min) 890
SPARKADV(°) 8
IAT(°F) 136
MAF(lb/min) 0.372
O2B1S1(V) 0.160
------------------
LOAD_PCT(%) 18.0
ETC(°F) 198
RPM(/min) 889
SPARKADV(°) 7
IAT(°F) 138
MAF(lb/min) 1.509
O2B1S1(V) 0.110
------------------
LOAD_PCT(%) 45.1
ETC(°F) 198
RPM(/min) 1844
SPARKADV(°) 29
IAT(°F) 138
MAF(lb/min) 1.993
O2B1S1(V) 0.205
------------------
LOAD_PCT(%) 20.8
ETC(°F) 199
RPM(/min) 2630
SPARKADV(°) 35
IAT(°F) 138
MAF(lb/min) 1.623
O2B1S1(V) 0.095
------------------
LOAD_PCT(%) 31.4
ETC(°F) 199
RPM(/min) 2710
SPARKADV(°) 36
IAT(°F) 136
MAF(lb/min) 0.599
O2B1S1(V) 0.015
------------------
LOAD_PCT(%) 43.9
ETC(°F) 199
RPM(/min) 1831
SPARKADV(°) 26
IAT(°F) 136
MAF(lb/min) 3.070
O2B1S1(V) 0.900
------------------
LOAD_PCT(%) 63.9
ETC(°F) 199
RPM(/min) 4128
SPARKADV(°) 38
IAT(°F) 135
MAF(lb/min) 4.607
O2B1S1(V) 0.910
------------------
LOAD_PCT(%) 61.2
ETC(°F) 201
RPM(/min) 3565
SPARKADV(°) 27
IAT(°F) 133
MAF(lb/min) 4.041
O2B1S1(V) 0.110
------------------
LOAD_PCT(%) 55.7
ETC(°F) 201
RPM(/min) 2832
SPARKADV(°) 28
IAT(°F) 131
MAF(lb/min) 2.287
O2B1S1(V) 0.810
------------------
LOAD_PCT(%) 28.2
ETC(°F) 203
RPM(/min) 2856
SPARKADV(°) 36
IAT(°F) 131
MAF(lb/min) 1.993
O2B1S1(V) 0.840
------------------
LOAD_PCT(%) 31.8
ETC(°F) 203
RPM(/min) 2838
SPARKADV(°) 36
IAT(°F) 129
MAF(lb/min) 2.201
O2B1S1(V) 0.780
------------------
LOAD_PCT(%) 19.6
ETC(°F) 205
RPM(/min) 2712
SPARKADV(°) 34
IAT(°F) 127
MAF(lb/min) 1.230
O2B1S1(V) 0.085
------------------
LOAD_PCT(%) 18.0
ETC(°F) 205
RPM(/min) 2723
SPARKADV(°) 32
IAT(°F) 127
MAF(lb/min) 0.947
O2B1S1(V) 0.775
------------------
LOAD_PCT(%) 9.4
ETC(°F) 205
RPM(/min) 2606
SPARKADV(°) 28
IAT(°F) 127
MAF(lb/min) 0.602
O2B1S1(V) 0.000
------------------
LOAD_PCT(%) 12.2
ETC(°F) 205
RPM(/min) 1774
SPARKADV(°) 25
IAT(°F) 127
MAF(lb/min) 0.564
O2B1S1(V) 0.845
------------------
LOAD_PCT(%) 19.6
ETC(°F) 207
RPM(/min) 1413
SPARKADV(°) 21
IAT(°F) 126
MAF(lb/min) 5.926
O2B1S1(V) 0.755
------------------
LOAD_PCT(%) 71.4
ETC(°F) 207
RPM(/min) 5008
SPARKADV(°) 23
IAT(°F) 127
MAF(lb/min) 1.368
O2B1S1(V) 0.420
------------------
LOAD_PCT(%) 78.0
ETC(°F) 207
RPM(/min) 5161
SPARKADV(°) 24
IAT(°F) 127
MAF(lb/min) 1.019
O2B1S1(V) 0.055
------------------
LOAD_PCT(%) 72.9
ETC(°F) 207
RPM(/min) 4384
SPARKADV(°) 23
IAT(°F) 126
MAF(lb/min) 5.443
O2B1S1(V) 0.915
------------------
LOAD_PCT(%) 72.2
ETC(°F) 207
RPM(/min) 3583
SPARKADV(°) 21
IAT(°F) 124
MAF(lb/min) 7.841
O2B1S1(V) 0.810
------------------
LOAD_PCT(%) 72.2
ETC(°F) 208
RPM(/min) 3809
SPARKADV(°) 21
IAT(°F) 122
MAF(lb/min) 8.238
O2B1S1(V) 0.840
------------------
LOAD_PCT(%) 27.5
ETC(°F) 208
RPM(/min) 3073
SPARKADV(°) 18
IAT(°F) 122
MAF(lb/min) 6.656
O2B1S1(V) 0.215
------------------
LOAD_PCT(%) 47.1
ETC(°F) 208
RPM(/min) 3081
SPARKADV(°) 36
IAT(°F) 120
MAF(lb/min) 1.821
O2B1S1(V) 0.860
------------------
LOAD_PCT(%) 30.2
ETC(°F) 210
RPM(/min) 2868
SPARKADV(°) 36
IAT(°F) 118
MAF(lb/min) 2.680
O2B1S1(V) 0.890
------------------
LOAD_PCT(%) 19.6
ETC(°F) 212
RPM(/min) 2610
SPARKADV(°) 32
IAT(°F) 118
MAF(lb/min) 0.632
O2B1S1(V) 0.055
------------------
LOAD_PCT(%) 10.6
ETC(°F) 212
RPM(/min) 2248
SPARKADV(°) 28
IAT(°F) 118
MAF(lb/min) 0.602
O2B1S1(V) 0.000
------------------
LOAD_PCT(%) 13.3
ETC(°F) 212
RPM(/min) 1497
SPARKADV(°) 13
IAT(°F) 118
MAF(lb/min) 0.509
O2B1S1(V) 0.020
------------------
LOAD_PCT(%) 18.8
ETC(°F) 212
RPM(/min) 1061
SPARKADV(°) 8
IAT(°F) 118
MAF(lb/min) 0.476
O2B1S1(V) 0.090
------------------
LOAD_PCT(%) 19.6
ETC(°F) 212
RPM(/min) 885
SPARKADV(°) 8
IAT(°F) 118
MAF(lb/min) 0.639
O2B1S1(V) 0.855
------------------
LOAD_PCT(%) 69.0
ETC(°F) 212
RPM(/min) 1705
SPARKADV(°) 18
IAT(°F) 118
MAF(lb/min) 3.557
O2B1S1(V) 0.335
------------------
LOAD_PCT(%) 14.1
ETC(°F) 212
RPM(/min) 2303
SPARKADV(°) 13
IAT(°F) 120
MAF(lb/min) 5.640
O2B1S1(V) 0.175
------------------
LOAD_PCT(%) 72.9
ETC(°F) 212
RPM(/min) 5181
SPARKADV(°) 41
IAT(°F) 122
MAF(lb/min) 8.586
O2B1S1(V) 0.870
------------------
LOAD_PCT(%) 9.8
ETC(°F) 212
RPM(/min) 3276
SPARKADV(°) 20
IAT(°F) 122
MAF(lb/min) 9.651
O2B1S1(V) 0.090
------------------
LOAD_PCT(%) 8.6
ETC(°F) 212
RPM(/min) 2967
SPARKADV(°) 24
IAT(°F) 122
MAF(lb/min) 5.127
O2B1S1(V) 0.805
------------------
LOAD_PCT(%) 42.7
ETC(°F) 212
RPM(/min) 3343
SPARKADV(°) 37
IAT(°F) 120
MAF(lb/min) 0.963
O2B1S1(V) 0.830
------------------
LOAD_PCT(%) 16.1
ETC(°F) 212
RPM(/min) 3362
SPARKADV(°) 38
IAT(°F) 118
MAF(lb/min) 1.077
O2B1S1(V) 0.060
------------------
LOAD_PCT(%) 7.8
ETC(°F) 212
RPM(/min) 3325
SPARKADV(°) 28
IAT(°F) 118
MAF(lb/min) 0.656
O2B1S1(V) 0.025
------------------
LOAD_PCT(%) 16.9
ETC(°F) 212
RPM(/min) 3343
SPARKADV(°) 39
IAT(°F) 118
MAF(lb/min) 1.947
O2B1S1(V) 0.085
------------------
LOAD_PCT(%) 23.5
ETC(°F) 212
RPM(/min) 3404
SPARKADV(°) 40
IAT(°F) 118
MAF(lb/min) 1.799
O2B1S1(V) 0.080
------------------
LOAD_PCT(%) 49.4
ETC(°F) 212
RPM(/min) 3553
SPARKADV(°) 20
IAT(°F) 117
MAF(lb/min) 9.372
O2B1S1(V) 0.280
------------------
LOAD_PCT(%) 47.1
ETC(°F) 210
RPM(/min) 3837
SPARKADV(°) 40
IAT(°F) 115
MAF(lb/min) 1.086
O2B1S1(V) 0.250
------------------
LOAD_PCT(%) 72.9
ETC(°F) 208
RPM(/min) 4017
SPARKADV(°) 21
IAT(°F) 113
MAF(lb/min) 1.067
O2B1S1(V) 0.055
------------------
LOAD_PCT(%) 8.2
ETC(°F) 208
RPM(/min) 3736
SPARKADV(°) 28
IAT(°F) 113
MAF(lb/min) 0.772
O2B1S1(V) 0.000
------------------
LOAD_PCT(%) 8.2
ETC(°F) 208
RPM(/min) 3384
SPARKADV(°) 28
IAT(°F) 113
MAF(lb/min) 0.743
O2B1S1(V) 0.000
------------------
LOAD_PCT(%) 9.8
ETC(°F) 208
RPM(/min) 3078
SPARKADV(°) 28
IAT(°F) 113
MAF(lb/min) 0.791
O2B1S1(V) 0.000
------------------
LOAD_PCT(%) 10.6
ETC(°F) 207
RPM(/min) 2777
SPARKADV(°) 32
IAT(°F) 113
MAF(lb/min) 1.786
O2B1S1(V) 0.870
------------------
LOAD_PCT(%) 9.4
ETC(°F) 207
RPM(/min) 2516
SPARKADV(°) 28
IAT(°F) 113
MAF(lb/min) 0.635
O2B1S1(V) 0.000
------------------
LOAD_PCT(%) 10.2
ETC(°F) 205
RPM(/min) 2176
SPARKADV(°) 28
IAT(°F) 113
MAF(lb/min) 0.564
O2B1S1(V) 0.000
------------------
LOAD_PCT(%) 17.3
ETC(°F) 205
RPM(/min) 1181
SPARKADV(°) 11
IAT(°F) 113
MAF(lb/min) 0.485
O2B1S1(V) 0.825
------------------
LOAD_PCT(%) 20.0
ETC(°F) 205
RPM(/min) 1046
SPARKADV(°) 10
IAT(°F) 113
MAF(lb/min) 0.481
O2B1S1(V) 0.180
------------------
LOAD_PCT(%) 72.2
ETC(°F) 203
RPM(/min) 4062
SPARKADV(°) 22
IAT(°F) 113
MAF(lb/min) 6.802
O2B1S1(V) 0.865
------------------
LOAD_PCT(%) 74.1
ETC(°F) 203
RPM(/min) 3572
SPARKADV(°) 28
IAT(°F) 115
MAF(lb/min) 4.254
O2B1S1(V) 0.780
------------------
LOAD_PCT(%) 40.4
ETC(°F) 203
RPM(/min) 4044
SPARKADV(°) 32
IAT(°F) 115
MAF(lb/min) 3.911
O2B1S1(V) 0.825
------------------
LOAD_PCT(%) 52.2
ETC(°F) 203
RPM(/min) 4285
SPARKADV(°) 39
IAT(°F) 115
MAF(lb/min) 4.974
O2B1S1(V) 0.920
------------------
LOAD_PCT(%) 36.9
ETC(°F) 203
RPM(/min) 3535
SPARKADV(°) 41
IAT(°F) 117
MAF(lb/min) 2.098
O2B1S1(V) 0.090
------------------
LOAD_PCT(%) 36.5
ETC(°F) 203
RPM(/min) 3566
SPARKADV(°) 30
IAT(°F) 117
MAF(lb/min) 3.836
O2B1S1(V) 0.835
------------------

sixshooter

iTrader: (12)

A stock o2 sensor is worthless, or did you read that ^^^^ info that people who are trying to help you were giving you.

Are you running an o2 clamp device or not? This is a very important question to answer before continuing.

Are you running stock injectors or have you upgraded?

hovermike

There's no wideband o2 sensors (as such, the A/F readings are the o2 sensor readings between 0 and 0.9 volts (0.9 volts being rich, 0.45 being stoich)). The plugs are gapped at the stock settings for the 7's, which I believe is .035. This was originally an FMI kit that didn't ping (this badly) and I'm trying to stay stock... I'm looking for an easy answer, if there's not one, that's fine. If everyone here has gone to non-stock, then I'll go that route when there are more funds available.

sixshooter

iTrader: (12)

https://www.miataturbo.net/miata-parts-sale-trade-5/new-olderguy-o2-clamps-7987/

levnubhin

iTrader: (30)

If you want to fix your problem the first thing you need to do is get a WB O2. Did you test the timing like Budget racer told you to?
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hovermike

O2 clamp looks like the way to go - but does it have to sit next to the ECU and have a vacuum line run through the firewall? Ideally, I'd like to have this all sitting inside the engine bay...

As for timing, I haven't gotten my hands on a timing light yet. The MSD is set for 6 degrees of retard at >4psi... Would taking 6 degrees off the ECU's 21 degrees of advance be enough?

I'm just having a hard time understanding why a stock FMI setup from 2001 (yes, it's very old, but I've been replacing/rebuilding parts like crazy since the head gasket job) wouldn't be able to keep this car from pinging under boost. I've got a max of 6psi, so this shouldn't be difficult to get working w/o having to go the whole non-streetable route (don't want to have to find a person that sells state inspection stickers for 5x cost).

dustinb

The reason it isn't stopping your car from pinging is because you have no idea what your base timing is, or your air/fuel mixture. Air temps could also be a culprit. My guess is your timing is completely wrong. A timing light without advance (which is what you need) can be found for the $40 range. Buy one.

And narrow band O2 readings are completely 100% useless. Please don't ever rely on them. If you can't afford a wideband, find someone doing a cheap dyno and take your car there. You'll get a full print out of your AFR.

levnubhin

iTrader: (30)

How can you assume it's timing related without knowing what your afr's are? For all we know you could be lean as hell.
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samnavy

iTrader: (7)

Your fuel pump could be shot or fuel filter clogged preventing enough fuel from getting through. Can you tell if it's down on power?

For $180 or so, an LC1 is really the next logical step to troubleshooting. You'll need a bung welded onto your exhaust... pre-cat if possible.

I'd also highly recommend a fuel pressure gauge... cheap way to diagnose pump or filter. A new filter is only about $15... good piece of mind in a boosted car to change it every time you do the timing belt.

sixshooter

iTrader: (12)

There are several places in town that will dyno a car at $30 for three pulls, but that will be a big waste of time without already knowing what your true timing and fueling looks like.

Basic tools you will need to own a turbo car with bandaids:
$35 timing light http://www.jegs.com/i/Equus/390/3551/10002/-1
I think Oreillys has one for $40 in Austin.

$209 Innovate LC-1 Wideband from DIY Autotune.http://www.diyautotune.com/catalog/i...796-p-152.html

Basic device that is required when running bandaids (it is one of the bandaids):
Olderguy O2 Clamp

Since you said it had not been right since the head gasket change:
1) Your ignition timing may be off. You need a timing light.
2) Your cam timing might be off, either one or both cams may be off a tooth.
3) You said the head was rebuilt. Did they deck it or true it? You may be at higher compression ratio now.
4) Are you using a Mazda head gasket or some other brand? There were year model differences in the way the coolant flow was designed to circulate. There are differences in thickness as well which will affect compression ratio.
5) Is the thermostat installed with the little bleed hole at the top or not? You may have air in your head and this may compromise cooling enough to cause detonation without showing much temp rise on the gauge.


There are more variables than this, but that is a start. If you want to DIY, you need to have the basic diagnostic tools and understand how these things interact. Otherwise you might do better to spend some money with a shop to have it done for you. It will either cost you effort in reading and learning or money. But it will cost you one or the other. It will not be free.

Why did your head gasket fail originally? Did it overheat?

autoluxury

that and are you running 93 octane or 87?

hovermike

Well, to be honest, it did ping before the rebuild (may have very well led to the need for the head gasket as it was my wife's daily driver and she wasn't one to watch the temp gauge). At the last dyno run where I was using A/F ratios, it was running lean. Corky Bell himself was looking at the fuel pressure and noted that the pressure was fine and that I might need to go to bigger injectors. This was at 8lbs, so the stockers should be fine @ 6 (I have installed rebuilt injectors since the rebuild). The odd part was that a dyno run a couple months later showed no pinging and RWHP at 187 (20 higher than the lean day). A shop had installed the check valve on the AFPR backwards at some other point that could have been very well locking up the injectors.

The head had .015 shaved - Corky helped out with the combustion chamber volume (when the AFPR was getting rebuilt) and it was a negligible change.

There is absolutely no carbon in the combustion chamber, I had everything as clean as an operating room before putting the head back on w/ a Felpro gasket (9717PT). The head had a full job, and I also installed the coolant reroute (and yes, the thermostat is installed correctly). The cam / crank timing was all dead nuts on when we put the timing belt on - the car runs beautifully below 2lbs. I'll have to get the timing light in case the head rebuild guy replaced the CAS seal and inadvertently advanced the timing.... it does feel like it's pulling better at low rpms...

Everything is as it should be, 93 octane gas since we got the car from my friend who had the turbo installed (2001 initial install, 2004 when we bought the car). I was just hoping someone had a similar experience and would be able to say 'Aha!...' I agree about cost no matter what. I've had bad luck with respectable shops who are too busy to accurately diagnose an issue and fixed several issues that they had created while I was replacing the head gasket, so this will be DIY. Ending up with even more tools isn't a bad thing... and the timing light will be here Wed...

hovermike

Problem solved.

Check valve on AFPR was sticky preventing boost from getting out which caused fuel pressure to go 110+psi - locking the injectors.

Need to get a restrictor on the signal line as well...