jeffas000073

I'm disconnecting the take out (not the one connected to the coil)....that is the EST right?

Tuned Performance

iTrader: (92)

ULTM8Z

jeffas000073

See??? I'm an idiot!! I'll try this again. Sorry.......

Tuned Performance

iTrader: (92)

ULTM8Z

Dude, if you set the timing to 6 with the EST connector still attached, that could be the source of your problem... you just overrode the timing tables in the ECM. You basically just subtracted ~18 deg of timing from everywhere in the table...

jeffas000073

Possibly, but it was running not so good even before I touched the timing. In fact even after I disconnected the 'not correct' ECT and reset the timing, it still ran pretty much the same as before. I think the course of action we have planned out is what's going to ultimately fix this thing. Based on everything that's been done to the car thus far, and all the information I've acquired from you and others, I think a non-stock cam is the most likely root cause thus requiring a specialized tune.

I'll go back tomorrow, disconnect the right damn EST wire this time, and get the initial timing to 6 degrees BTDC. I guess I've never wanted to see an SES light trouble code this much before, but at least if I do after disconnecting the ECT, I'll know the ECM and MEMCAL are functioning correctly. Since I don't have a code clearer (I just made that word up I think), all I have to do is disconnect the battery for a while and the code will clear, correct?

jeffas000073

Mike....by the way....I received your email and next steps for the tuning. Thanks!! I'm looking forward to moving forward with tuning!

ULTM8Z

yep just disconnect the ECM and that will clear the codes.

jeffas000073

So for anyone following this saga along, I figured I'd keep this post up to date. I have a very understanding 3rdgen forum member helping me out with the tune, so I'm not looking for any programming help at this point. I'm not listing who is helping in case he doesn't want people swarming him for help, but he is obviously free to admit on the forum that he's the one that's been sucked into this!!!

I correctly set the timing to 6 degrees BTDC (once you guys told me the errors of my way by initially mistaking the tach wire for the EST wire). I ran another Tunerpro data log and used the histogram plotting feature to map out my BLM values at the various RPM's. My observations:

• In open loop, the car is not driving too well. Once it goes closed loop, driveability greatly improves (but still not great). The attached .xdf file only captured the closed loop portion of the drive.
• Most noticeable poor performance is in the 1500-1900 RPM range. This is true for both open and closed loop. In open loop, driveability is by far the worst. I guess this atleast proves my O2 sensor is working.
• Looking at the BLM histogram, numbers are high in that 1500-1900 RPM range

If anyone wants to comment on what they are seeing, please feel free. I'm learning more about how all this works every day, but the more info, the better.

I'll keep this post updated as things change.

jeffas000073

Quick update......I've run a revised .bin on the ECM and things are improving. Just received another updated .bin and will run that tomorrow. There is light at the end of the tunnel!!!

jeffas000073

Latest update: Reviewing data logs, it was determined that my knock counts were rather numerous even though I couldn't hear pinging or knocking while I was driving. To see if the knocks (and the resultant ECM pull back on the timing) could be eliminated, I added an octane boost to my already 91 octane premium fuel and data logged again. I wasn't able to capture the open loop portion of the drive, but while running closed loop........there were ZERO knock counts recorded. Maybe we're on to something! The car seemed to be running pretty good, but there was still a slightly noticeable 1600-2000 RPM engine bog. It didn't matter the load on the engine......light throttle or hard throttle....the bog was there. As soon as the RPM was out of that range, the engine was pretty good.

To see if the knock elimination with octane boost was just an anomaly, I let the car sit over night and data logged again the next morning. This time I was able to capture both open and closed loop. Of course, during open loop, the knock counts were there again. The 1600-2000 RPM engine bog was much more severe in open loop. But then the engine went into closed loop about 2-3 minutes into the run, and it started to run a little better, however TunerPro was still showing knock counts. The super strange thing is that at approximately 8.5 minutes into this run, the knock counts completely disappeared. Once again, the car ran just like it did the day before with only the moderate 1600-2000 RPM issue. Using my very limited knowledge set on ECM programming, it seems that for whatever reason, timing is being retarded at that RPM range and much much much more so when in open loop.

My very patient Tuner friend suggested I swap in a new knock sensor. I picked that up yesterday (along with the connector) and went to a local repair shop this morning to have it installed. Much easier to make the swap when the car is on a hoist verses my old *** laying on the ground and trying to get it out. Before we were going to install it, we started the car, lifted it up and went underneath to have one last look. Once we got our ears right next to the knock sensor, we could hear a slight pinging/knocking/rattling sound......and it was coming from the exhaust manifold right next to the knock sensor. It appears as though the gasket is garbage and there is a leak. So now my hypothesis is the knock sensor is picking up this noise big time when the engine is cold and killing my timing. Once it warms up and the gasket expands, the leak is somewhat sealed, the noise is far lessened, knock count goes away, and less of my timing is messed with.

Of course the shop couldn't replace the gasket today, so I left it and they will replace it Monday or Tuesday once they get a quality gasket (not the crap that the engine rebuild place used). Since I already had a new knock sensor and connector, they are going to replace that too. Once I get it back, I'll run some more data logs and see where things stand. If it still is recording knocks, I'm going to unhook the sensor and run the car again to see what performance is like......but I really hope I won't have to.

So I'm trying to think positive about this car for at least today and am hoping the knock is eliminated with this repair. Assuming it is, can the ECM be programmed to not pull as much timing out in the 1600-2000 RPM range? I've asked my Tuner if this was possible and I'm waiting to hear back. In addition, with some of the previous modified bin revisions that were sent, he was able to get the BLM's much better and more on the rich side (I'm currently running pretty lean with numbers usually well north of 130). His big concern is that 'if' the cam was replaced to something a little more than stock, the compression ratio could be up too much. Since the heads weren't tweaked, maybe they can't handle the increased compression? I say 'if' the cam was replaced because I honestly don't know for sure. Two years ago when this project started, I had blindly asked the builder to see what he could do to make the engine have more horsepower and he mentioned he may try to do something with the cam, but I never received any specs back and the engine builder is no where to be found today. Sort of my luck.

I have zero plans on tearing into the engine to see what is what, so at this point I'm hoping tuning can solve most of the issue. Again, when in closed loop and some heat in the engine, it runs really good. With the 1600-2000 RPM thing eliminated, it would be running excellent with zero complaints from me.

If anyone has any additional ideas/insight (besides telling me to shorten up my notes), I'd really like to here them. My Tuner also reads this, so I'm sure he'd be interested too. Thanks to Everyone for reading and following along.

jeffas000073

Here is the last run I had with the octane boost from the start at cold/open loop all the way through closed loop (about 20 min of driving).

jeffas000073

I'm sure I bored everyone long ago and no one is even keeping up on this, but posting helps keep me somewhat sane. Here is the latest update:

The knock sensor still thinks it's hearing knock, therefore telling the ECM to pull out a ton of timing out in the 1600-2000 RPM range. This occurs even after doing the following:

1. Timing purposely pulled out of the bin (about 10 degrees worth) in the main RPM/MAP range where the most knock retard was being commanded. ECM STILL commanding about a 10-20 degrees of timing retard due to perceived knock. However, that isn't always consistent. Sometimes it's 0 degrees, sometimes it's 25 degrees
2. Timing at idle with the EST disconnected checked and is at 6 degrees BTDC
3. Timing at 2000 RPM with EST connected showing about 28 degrees
4. Octane level increased to well over 94 (premium fuel plus added octane booster)
5. BLM's set to be on the rich side to prevent any lean conditions
6. Spark plugs (1-4) checked; all show normal condition and operation.
7. Exhaust manifold gasket replaced; was torn in a corner
8. Transmission/brake lines separated
9. ICM/Wires/Distributor/Cap/ECM all checked and either replaced or tested out good

I'm attaching 3 datalogs if anyone wants to have a peek:

• 101518_timing.zip run with items 1-9 all accounted for
• 101518_mod2-zip run with items 2-9 accounted for (no timing programmed out)
• 101418_knock_removed.zip with items 2-9 accounted for (no timing programmed out)

.
This has gotta be FALSE KNOCK, right?????

It seems pretty certain that if it were real knock due to increased compression/pre-detonation/low octane/etc, the combination of the above items 1-9 should have at least eliminated or greatly reduced real knock and resulting knock retard, but it didn't.

The only things I can think of that I could still do in an attempt to find the knock is adjust the valves/rockers to eliminate some lash (a little clicking, but nothing huge) and getting it up on a lift again and pounding around to try to find something buzzing/rattling.

At this point, I'm leaning towards just reducing the knock sensor sensitivity or eliminating it all together. The engine has proven to run good when the ECM ignores the knock counts via a revised bin. But my Tuner friend (and myself for that matter) are a little hesitant to do that.

Before knock counts are permanently programmed out of the equation, does anyone have any other ideas/suggestions? I do not want to grenade this engine.

DynoDave43

iTrader: (11)

Not bored. Just don't understand it all. Reading to learn, but nothing to contribute. Sorry.

T4Turtle

It does sound like false knock here. If there is no evidence on the spark plugs of any aluminum "peppering" pulling timing and adding octane does not correct it. You had mentioned an exhaust leak did the gasket correct a leak and is the other side OK? Also any exhaust rubbing anywhere could cause false knock.

jeffas000073

Well the drama continues. The car has been at a tuner for the last couple of weeks while they play around with it trying to determine the source of my knock and resultant timing retard. They put it on the dyno and the initial run was something close to 165 whp. They ended up setting the timing to 12 BTDC, ran it on the dyno again, and came up with 228 whp and 374 lb-ft torque. Not too shabby.

The problem is when I actually drove it, the spark knock was crazy evident at the 1500-1900 RPM range. Anything below of over and there was no knock. Tuner Pro continues to confirm that the knock is there in that range and that timing is being pulled out mainly when MAP is over 50%.....below 50%, there is essentially zero timing pull out.

However, the car is running awesome. Idles smooth, pulls hard, doesn't fall on its face at all even with the timing being pulled out (when at 12 BTDC). If I were to but earmuffs on, I'd have zero issues! But I think we all know that would be the fool's way out of this issue. Something is obviously wrong with my engine causing spark knock. Putting the timing back to 6 BTDC results in less performance and essentially the exact same amount of knock and timing retard in the range mentioned above.

So I know I'm bringing this thread back from the dead, but I need some additional insight as to what is wrong with this car. Could a bad EGR valve/solenoid cause any of this? I have had the CEL illuminate a couple of times showing me a code 32, but I can clear it and it goes away. I also know the plugs are gapped wrong (their at .060 and should be at.035.....tuner put the wrong plugs in it, but the issues existed before swapping plugs).....but the engine isn't misfiring.

The biggest thing to note is that when the knock sensor information is ignored by the ECM via bin modification and no timing is pulled out, this car runs awesome in every aspect. When base timing was set at 6 BTDC, it ran pretty good....no real complaints. Knock was minimal and I had to listen close to hear it. At 12 BTDC, the engine rocks, but the knock is really evident. But let the ECM 'listen' to what the knock sensor is telling it to do, we have whole different story......thus the reason for this ongoing post.

Any more thoughts from you guys?????

T4Turtle

I would not think you would only have pre-ignition going on only in this rpm range if it was due to heat or a hot spot. What is the A/F ratio in this range? I thought originally you were only seeing knock retard in data logs and not audibly hearing it. The knock sensor will pick up on anything that is vibrating enough to cause similar frequency to what knock is. If you know the exhaust is not leaking or rubbing anywhere then look to other items that rotate like your flex plate, torque converter, balancer, etc... Anything that rotates will create a frequency and if something is out of balance is loose or has a crack in it could create enough to audibly hear this and set off the knock sensor. Do you feel this vibration in the car or is it just audible?

jeffas000073

T4Turtle.....when the timing was set at 6 BTDC, I could only faintly hear the knock at the low RPM range I've mentioned, but the timing was still being pulled out of it big time. Tuner Pro validated the timing retard and also confirmed the knock counts. When the tuner place adjusted the timing to 12 BTDC, the engine ran great, but the knock was now VERY apparent at the my beloved RPM range......like the volume was turned up to 10. Tuner Pro still was showing the knock counts and still pulling out timing very similar to what it was doing at 6 BTDC. But I'm telling you.....the engine really liked (performance wise) being at 12 BTDC.....and the dyno printout proved that. Even with the timing being pulled out, it was running great.

But it is very obvious that changing the timing increased the audible knock. While I almost could have lived with what I was getting at 6 BTDC, the 12 BTDC isn't. Something has got to be wrong. It should also be noted that I'm running higher octane fuel (93), so bad gas isn't the issue.

The only thing I have left that remotely could be causing this is a bad EGR valve. The CEL light has come on a few times. I really don't think this is the root cause, but at this point I'm not sure what else to do without ripping the engine apart and starting from scratch.

Another thought I've had.....since the distributor was replaced early on with an after market, could there be any potential that it could be faulty and result in a knock? I'm pretty sure the performance would be off and if anything the engine would be missing, so I don't know if that is even a potential root cause or not.

The bottom line is that when the knock count is ignored by the ECM, the car runs great....no issues.....even at 6 BTDC. I think that alone tells me the distributor/ICM/plugs/wires/cap/rotor/sensors are all working as they should.

I really need some 'ah ha' clarity on this one...........................

T4Turtle

If the EGR is hanging open and making the combustion temperature hotter than usual this could be an issue and would be worth just blocking off for testing purposes.

Do you know what the A/F ratios are during this audible knock and have you tried adding fuel just in this range to see if it helps? Have you tried just pulling timing out in this rpm/MAP range?

If there is an exhaust leak and it is making 60+ more HP with the more advanced timing I would think this could make an exhaust leak louder as you should be moving more through the exhaust. If it is as audible as you state it is I would think the spark plugs would have aluminum specks on the ceramic.

ULTM8Z

I recall I had audible pinging in the same rpm range under load when I was running 10.1:1 compression with my AFR heads when trying to run the LT4 timing map. 1500 to around 2500 rpm. Above or below that, I didn't hear anything (and the TP data backed it up). When I dropped the compression down to around 9.8, that all went away.

ULTM8Z

Agreed, I think the EGR has to be eliminated from the cause tree...

T4Turtle

So maybe less aggressive timing and/or more fuel in this range would take care of this.

jeffas000073.... Were the heads cleaned up enough to lower the chamber size? Also was the block zero decked?

jeffas000073

T4Turtle....those are really good questions. If I could go back in time and do this all over again, questions like that would have most definitely been asked, answered, and documented. But given I had never done anything like this before, I was too trusting and made a very false assumption that because I was paying the a-hole engine rebuilder good money, all would be good. I screwed that one up big time......a major and expensive lesson learned.

At this point, I have what I have.....and that is very little knowledge as to what was done to the engine of my car. Getting that information is not possible, so all I can do is try to figure this out and move forward. The only way to find out about the heads or the block is to rip the whole thing apart and start over. I've already dumped a lot of money into this thing and won't be able to do anything like that this year.

That being typed.....I'm having the tuner place check the EGR to see if it functions. They'll most likely just put a vacuum tester to it to see if it holds and skip testing to see if the solenoid is working. I obviously trust no mechanic in Michigan at this point to do anything ethical and/or correctly, so I'll have to spoon feed them on what steps they should already know to take and most likely **** them off in the process. So be it.

My frustration level is off the charts.

ULTM8Z

if it's any consolation, I know exactly what you're going through. I battled an idle misfire for several years before I finally figured it out. this was about 10 years ago.... i had the engine apart numerous times, replacing this and that (sometimes twice over).

One of the most frustrating experiences I've ever been through. Some of the old timers here probably remember it...

jeffas000073

Hopefully someday soon I can be one of those guys that can commiserate with others over issues like this. I'm just waiting to see that light at the end of the tunnel.....and not have it be another train!!!

T4Turtle

Is your tuner actually tuning your chip? If so and adding fuel or pulling timing in your tune in this range is not helping then maybe some thicker head gaskets could help like it did with ULTM8Z reduction in compression ratio. Should not be a bad job as everything was recently apart so you shouldn't have to worry about corroded fasteners and it's salt season in Michigan anyway so I am sure you are not driving it until spring.

jeffas000073

I've already had help tuning the chip so more fuel was added and/or timing pulled out......nothing seemed to help. We had also discussed the head gaskets and their contribution to increased compression. While that could be something to do, that's still tearing into the engine quite a bit. If the EGR turns out to be another fail, then I guess I'm going to have to see figure out next steps.

I mentioned it a couple of posts ago, but is there any possibility a faulty distributor could be causing all of this? Maybe it's doing something to the timing inducing the knock.....but I'm pretty sure that's not the root cause either.

ULTM8Z

only if the distributor is somehow adding timing that the computer is unaware of...

jeffas000073

What fault in a distributor would cause it to add the timing that it shouldn't be?

ULTM8Z

that's the thing...I dont know of any internal fault like that... the only thing could be is if you were off by a tooth or something on the distributor gear.

but I think you verified spark timing accuracy with your dial back timing light, no?

jeffas000073

Yup.....I did verify with a light.