Haltech - engine appears to hit brick wall ~ 4k rpm

hi all,

I'm running an elite 1500 with the nexus software and my car developed a new quirk after uncovering it from a long winter's rest. At around 4k rpm, even though the throttle is nailed wide open, sometimes the engine will just completely cut out for a split second, then immediately recover.

At first I thought I was hitting an overboost condition, but after reviewing the configuration I determined that this isn't the case. Logs show this event occurring at 21-22 psi with 22 being my static target, and 25 psi the cutoff. RPM cutoff is at 7250.

I attached a log and it's clearly observable at the 24 second mark if you look at tps and rpm at a minimum. I added the map too, but had to zip it as for some reason the forum software would not accept it in its default state.

Could someone recommend what channels I can start logging to help me track this down?

thank you in advance, any help is appreciated.

Hi Daniel,

i have looked @ your datalog and Ecu map. The Toyota 3SGTE Engine it is known for trigger system problems i already had to deal with.

I would check the Trigger / Home and rpm derivative parameters/Signals first. Also check the battery voltage parameter.

The Manifold pressure drops about 45 kpa @ the same point the rpm drop happens. I think the boost drop is a result not the issue.

hi Marian et al,

I finally had some time to run the car and record the event. It occurred around 6:19 in the attached log.

First time investigating this channel here, but it's interesting to me that on a 12 tooth trigger, sometimes i see 0 thru 11 (expected) and then I observe the counts going backwards. I'm not sure that is what is causing this issue though, I see a trigger hiccup where it seems to be lost between 4500 and 5k rpm, but the actual "brick wall" symptom occurred at 6k and the signal looks cleaner right up to the event.

What do you think? I have a spare engine being built with Camry oil pump/triggering and I'll be going away from this distributor-based reluctor trigger. That won't happen until later this year though, and it would be great to find a way to work around these symptoms and still drive the car in the mean time.

regards,

Daniel

Hello Daniel,

i have analysed your Data log. It took me a while but i have found your problem. The Vehicle Speed Sensor reports false values what causes the Launch control to activate.

Please take a look @ the attached pictures.

The trigger count parameter looks okay(was the same on the 3SGTE engine i have tuned).

Best Regards

Marian Marth

www.am-power.at

I am not sure how you thought to look for that, but THANK YOU!!! I don't think I would have ever come across it.

This is great and I will dig in to what's causing the signal issue. I probably need to take this time and change the launch control configuration to use a clutch switch instead of vss (gps), or at a minimum, change the gps location. I had my windows tinted at the beginning of the season and it never occurred to me that they'd potentially impact the GPS signal, as my speedometer also uses GPS and it's fine. It can probably handle micro-drops in signal though, unlike this...

major kudos due on this one.

Hello Daniel,

i am happy that i could help you with your issue.

I have looked @ your Speed Sensor Setup in the ECU Map and it is configured as a normal drive train sensor not a GPS Input!!!

Please take a look @ the attached pictures.

Wow, you're right. That's very surprising to me as I distinctly remember configuring this to match Haltech's instructions that came with the GPS module.

I corrected the misconfiguration and (after fixing some new boost leaks) I took the car for a spin and it drives so much better now! Thank you again for all of the help. It's so nice to have the car back on the road again and running normally.

cheers

daniel