At my wits end... ANY IDEAS? LS3 with 24X trigger.

[DLRacing]

Hi all,

I bought an RX7 already swapped with an LS3 motor that was running on an LS1 PCM with a cable throttle body.

I Installed an MS3Pro with the 58X drop-on harness, as I have the timing cover mounted CMP, and I assume a single tooth cam gear, since that was what the LS1 required.
I modified the CKP connector to fit the 24X pickup, and researched the sensors to determine that they would both operate on 5v without issue.
I also changed the knock sensors back to LS3 2-wire type.

I loaded the 6.0 base tune, and changed the trigger to LS1 type. I also setup my fan and A/C controls, and the added fuel pressure sensor.
Entered my engine parameters, (It's a 7 liter stroker with ported heads, a big cam, and a forged bottom end, but I don't know exact specs, it made over 540hp at the wheels with the LS1 PCM.)

I ran the injector and coil tests, and everything seems to be wired in the right sequence.
I located TDC and made a timing pointer, and checked cranking timing before pressurizing the fuel system. I tweaked the timing wizard by 3 degrees to bring it into agreement.

So, I tried to start it. Cranking speed seemed maybe a bit low, but the rpm in the log is very low and erratic.
I did get a couple pops from the exhaust, but nothing close to starting up.

So, I decided to put the drivers seat back in, and discovered my battery ground cable, which bolts to one of the seat mounts, was only finger tight.
This may well be the problem, but I'd already put stuff up for the night, so I put a charger on it for the night and will try again tomorrow.

Anyway, please take a look and let me know if you see anything else I should try.

Thanks,
David

I'll attach the tune and logs.
Any help would be appreciated.

[DLRacing]

I should mention I'm totally inexperienced with the Megasquirt, and with EFI tuning in general.
I understand the concepts of how they work, but the software and tables are completely new to me.
I've built and tuned carbureted motors, but nothing much more than bolt-ons on EFI cars to date.
This install is meant to be a learning experience for me as much as it is to improve the car.

[gjestico]

Is your crank wheel 24x or 58x ?

I think the "LS1" setting in the wheel section is specific to the unique GM 24X Gen3 wheel (1997-2004). The 58x wheel is treated the same as the 60-2 bosch wheel (common in Europe) in the settings. Maybe try that ? (60-2) ?

[nathaninwa]

I would suggest actually looking and finding out what you have. Pull the crank and cam sensors to get a visual. Crank is pretty clear, it's either a single toothed wheel or a wheel that is riveted together. The cam can be single half moon type or a 4 tooth style

Where did you read the crank sensor would work on 5v? And I'm guessing you redid the pinout too while getting it to fit

And please explain more about the battery wiring layout. Having it connected to the seatbelt bolt for the engine stuff is a huge red flag

[DLRacing]

It's definitely a 24X crank wheel, with the associated sensor, and the single tooth cam gear is necessary for it to have ran on the LS1 PCM.

I don't recall the exact thread, but someone on LS1tech pointed me to the manufacturer of the actual sensor, and it's specs allow it to run from around 3v to something like 24vdc.

The battery is in the bin right behind the seats, with a short ground cable to the seat bolt, not the seatbelt.
There's a 0 gauge cable through a battery switch to the starter and alternator, as well as the main fuse block up front.
The MS3Pro harness includes a 4 gauge cable, and a small white wire, that are connected through a fuse to the battery switch, and its ground wire is tied directly to the battery - terminal.

Other than the ground wire being loose, the battery power system is as robust on this car as any I've seen.

Thanks,
David

[CRSTune]

Your datalog shows multiple counts of sync loss, reason 91. Can you take a composite tooth log?

[nathaninwa]

Ahhhh, I misses the stroker crank part. I was thinking why would anyone put an ls1 crank in place of the way cooler ls3 crank!

Is there a ground cable from the battery or seat bolt to the engine block?

Also, try wasted cop and semi sequential fuel. This will use the crank wheel only till it gets running

And a side thought, I wonder if having a double pull-up on the crank wire might do something odd

Here is a link about sync loss 91. http://www.msextra.com/forums/viewtopic ... 31&t=55640

[gjestico]

How does the MS3 pro deal with the pull up resistor (or lack therof) for the crank sensor signal ?
Per the manual, the 24x style sensor has a built in pull up, But the 58x needs an external one, In the harness or on the ecu. Your 58x style harness may have the external pull up active. Not sure it that would affect things at all.

Also, Try taking the plugs out and cranking it with a timing light attached and watch to see if its sparking when it should. Also run a log and see if the sync issues are lessened with the plugs-out cranking (should be faster and smoother cranking)

[DLRacing]

[quote="CRSTune"]Your datalog shows multiple counts of sync loss, reason 91. Can you take a composite tooth log?[/q

I was just looking for the CKP and CMP in the log file. It doesn't appear there and I don't see it in the log profile setup either.
How can I log the CKP and CMP sensors?

Thanks

[DLRacing]

How does the MS3 pro deal with the pull up resistor (or lack therof) for the crank sensor signal ?
Per the manual, the 24x style sensor has a built in pull up, But the 58x needs an external one, In the harness or on the ecu. Your 58x style harness may have the external pull up active. Not sure it that would affect things at all.

Also, Try taking the plugs out and cranking it with a timing light attached and watch to see if its sparking when it should. Also run a log and see if the sync issues are lessened with the plugs-out cranking (should be faster and smoother cranking)

I think the 58X harness does have the pullup. I recall seeing some resistors spliced in at the ECU connector.
Unless the sensor has a really weak output driver, I'd think the extra pullup wouldn't matter, but it is something to check out.

Also, before I tried to start it I checked cranking timing with a timing light. That's how I arrived at the 3 degree offset in the Timing Wizard.
With 13 degrees cranking timing, I saw 16 degrees with the timing light. Setting the offset to 3 put it right on the money.

The sensor seems to be triggering intermittently, but the last log I did after fixing the ground cable, I got no rpm signal at all.

Is there a way to log the CKP and CMP sensor outputs directly?

I'm going out now to double-check the pinout on the CKP connector. Hopefully I can reach it without pulling the starter.

I'll also check for the pullup, and check the CMP pinout again as well.
I know I checked these over before installing the harness, but anything's possible.

[jsmcortina]

Is there a way to log the CKP and CMP sensor outputs directly?

Composite logger.

James

[DLRacing]

Is there a way to log the CKP and CMP sensor outputs directly?

Composite logger.

James

Thanks, I just found that tab, and I'm going out now to get those logged.

[DLRacing]

Here are my composite and tooth logs.

Am I correct in that the white trace is the crank sensor, and the red is the cam?
If so, it looks to me like the CKP is outputting a good signal, but the CMP is intermittent.

Any input is appreciated.

[DLRacing]

Did some more reading, and it seems that since the 24X reluctor does not have a missing tooth as such, the cam sensor is required for the engine to run at all.
The signal from my crank sensor looks really clean, and I can see the 24 distinct pulses in a repeating pattern, so I feel good that that one is wired correctly. (Can't get to it without removing the starter.)
I'm going to re-check the wiring on my cam sensor now, as that signal looks all funky on the composite log.

[nathaninwa]

It's a distinct pattern that does show crank position. It will run on that alone in wasted cop and semisequential fuel. Wasted cop is on the ignition tab and fuel is under the general or the reqfuel tab

[DLRacing]

It's a distinct pattern that does show crank position. It will run on that alone in wasted cop and semisequential fuel. Wasted cop is on the ignition tab and fuel is under the general or the reqfuel tab

Apparently this is not true.
I found the power and ground in my CMP sensor was reversed. Swapped those and reset to COP and full sequential and it fired right up and ran, poorly, but it did run. LOL I have a lot of tuning to do.

In the process my Innovate Dual Wideband gauge seems to have destroyed it's O2 sensors.
I had calibrated it previously, and it would read some level of O2 when the engine was trying to fire, but after it started, it just stayed at 22.4 on both sensors.
I called Innovate tech support and they said to recalibrate the sensors. I did and now I get Error 8 on both, which indicates bad sensors.
I can't believe those sensors are so fragile that 20 seconds of poor running at idle would destroy them. Doesn't give me a lot of confidence in their product.
I called them back and they recommend trying a firmware update for both the gauge and the LC-2, so now I have to go find a USB to Serial adapter.
I don't have a lot of confidence that this will fix it, but wish me luck.

David

[nathaninwa]

Weird. We couldn't get my buddy's fired up and I swore I switched to wasted stuff and it ran just fine, later To find a faulty sensor from it being dropped


We talked about innovate on another forum, and they just haven't gotten the heater control system down. Seems like every two months something pops up with a faulty sensor and your story exactly all over again! I had an LCx and threw it down the ateeet after two sensors in six months. Went aem and still running with 20,000 miles

Do you have a registered version of tuner studio?

[Dookie454]

It's a distinct pattern that does show crank position. It will run on that alone in wasted cop and semisequential fuel. Wasted cop is on the ignition tab and fuel is under the general or the reqfuel tab

Apparently this is not true.
I found the power and ground in my CMP sensor was reversed. Swapped those and reset to COP and full sequential and it fired right up and ran, poorly, but it did run. LOL I have a lot of tuning to do.

In the process my Innovate Dual Wideband gauge seems to have destroyed it's O2 sensors.
I had calibrated it previously, and it would read some level of O2 when the engine was trying to fire, but after it started, it just stayed at 22.4 on both sensors.
I called Innovate tech support and they said to recalibrate the sensors. I did and now I get Error 8 on both, which indicates bad sensors.
I can't believe those sensors are so fragile that 20 seconds of poor running at idle would destroy them. Doesn't give me a lot of confidence in their product.
I called them back and they recommend trying a firmware update for both the gauge and the LC-2, so now I have to go find a USB to Serial adapter.
I don't have a lot of confidence that this will fix it, but wish me luck.

David

was it real cold when your sensors fried? How far from the head are the sensors? I broke only one sensor in 10yrs by firing up my LT1 TA at 10F, because the sensor was ~6ft back on a y-pipe... water condensation hit it after about 10 seconds of running, POP. Done. Now I have it on a LS3 next to the factory sensor, ~1.5ft away from the head, no problems in cold weather.

[DLRacing]

Nathan,

I put an AEM UEGO in my Supercharged Miata, and never had a problem with it either.
I went with the Innovate on this car because of the dual gauge, plus I thought they were an established company.
We shall see how they handle this issue before I pass judgment, however.

I just picked up a USB to Serial adapter and am going to try updating their firmware.
The tech was adamant that I needed to do this, as they just issued the update very recently, and he mentioned it addresses the heater control routine.

Dookie,

It was about 60 or so degrees in my shop when I started it.
The sensors are in the header collectors, at 3 and 9 o-clock, and are mounted into spacers that place the tip of the sensor flush with the ID of the pipe. I also made aluminum heat sinks to try to keep the peak temps down, since the sensors are so close to the primary pipes.

Thanks.

[CRSTune]

I've generally had good results with AEM wideband kits and would very likely choose to use another AEM kit over an Innovate kit but with that being said, I've also had a few failures with the AEM provided sensors in customer's cars. On two separate incidents for instance, I've had a sensor fail within a day of being installed new (gauge was stuck lean). This was confirmed when we swapped out the sensors for new LSU4.9's. Our warranty requests were denied on the grounds that the sensor is a Bosch product, not AEM and therefore they were not responsible for replacing them.