SpartanSV

If it's actually staying at 14.5v sure, but a 3.5+ minute log with zero voltage change is weird. You'll typically see some fluctuation.

If you've confirmed with a meter that it is actually staying at that voltage then the alternator is probably fine.

shuiend

iTrader: (24)

Does the tach sort of jump around when you hit the limit?

I had a similar issue on a 99 where the pots were adjusted way off and it felt like it had a way lower rev limit. Not sure if this is relevant for the 1.6 CAS.

Ted75zcar

iTrader: (2)

bottom line is that it is very difficult to diagnose these types of problems from the other side of a computer. Unless somebody has experienced exactly the same thing, we are really just guessing.

As far as the constant 14.5V question, I have already answered that, but maybe I wasn't clear.

There maybe components in your car that prevent the voltage from exceeding 14.5V. This would most likely be done by consuming enogh current to drop the system voltage to whatever voltage the component has as a threshold (14.5V). This consumed energy is dissipated as heat. This is not a good thing.

I can tell you that an alternator that is not regulating properly and is sourcing too much current can result in behavior that looks very similar to what is in your video. The data in your logs, based on the little I know about your hardware, looks... unusual.

acey

Yes tack jumps around. The more throttle it has the more abruptly it jumps around. I have reset my pots and confirmed voltage using documentation from the megamanuel.

acey

Okay that makes sense now. Thanks for clearing that up.

Not sure if this information is relevant but the car ran normally with the stock ecu and same alternator. Does ms3x have some sort of voltage regulating system? You mentioned above to get the alternator tested, is this something that can be done at home? Or where do I get this done.

Apologies on asking questions on nearly everything you guys are saying, this is my first time diving in to a project like this. Seems like I should've studied up more

Ted75zcar

iTrader: (2)

The MS may have an over-voltage protection device on the input voltage lines. Did you make any other changes when you installed the MS? Will it still run with the stock ECU?

acey

I have not had the stock ecu in the car in a few weeks. I could put it back in this weekend to confirm the car still runs with it. Other than the MS I have put in a vTPS, AEM UEGO, and a new battery since mine was starting to go dead being pretty old.

acey

Earlier today I put back in the stock ecu. I was facing the same issue until I realized I had not put the stock TPS back in. After reinstalling that the car was able to surpass 2300 rpm and rev freely.

I got my vTPS from MK Turbo which is a AIP TPS314 97-122816 throttle sensor. When I was installing this on the car I was having trouble getting the wires out of the tps connector to flip the 5v reference and TPS signal wires. I ended up just leaving this and in result got inverted TPS values in tuner studio. There was a option in tuner studio that asked if I wanted to flip these and I selected yes. I was getting what felt like accurate TPS readings in my logs. Not sure what the culprit is here.

It makes sense that the OEM ecu does not understand the vTPS signal but I am lost as to what is causing to MS to have the same behavior.

Ted75zcar

iTrader: (2)

TPS was actually the first thing that I thought of, but your logs looked OK. A early NA runs 12V to the TPS pigtail. You have to disconnect this 12V and depending on how you wire it, connect it to GND or VREF. I had a very similar behavior on an AEM based early NA install.

Edit: I might have the WOT and IDLE signals swapped in my head, one of them goes to 12V.

acey

What determines weather you wire the 12 volts into the ground or 5v ref?

Ted75zcar

iTrader: (2)

Did the MKturbo TPS come with instructions? Wire the pigtail as the instructions instruct. I am sure there are writeups here as well.

you should be able to disconnect the tps with the MS and still run. Does it still "rev limit" with the TPS disconnected?

acey

No instructions came with vTPS, I'll find some and get that sorted. I reconnected my MS and just started car with no TPS and re calibrated the TPS in tuner studio to read zero. Still has that weird limit around 2000rpm it had before.

andym

Out of curiosity, does your ms3 not have the jumper in place to look for a variable tps? I know when I installed my ms3 I had to put in a jumper on the main board to tell it to look for a vtps.

gooflophaze

Leave the TPS disconnected - it's primarily used for acceleration enrichment. Slowly rev the engine - that will give the megasquirt time to meter the air - if it passes the 2300rpm wall, it's in your TPS. If not - it's something else. And when I say slow, I mean slowwwwly.

I'll throw this out there as well - I've had my MS3x w/ 3.56 board show errant values for voltage - in the nature of 18v. Verified the voltage with a mutlimeter and ended up reflashing the firmware to fix it.

shuiend

iTrader: (24)

its the standard SadFab VTPS bracket and KIA TPS. There are directions from Hi_Im_Sean floating around on mt.net in several places.

acey

I would assume so given that I build it using trubokitty's instructions. which jumper is it?

acey

Where were you measuring voltage at? I think just re flash firmware tomorrow just for a piece of mind. I hate this guessing game

gooflophaze

Pretty much anywhere, there shouldn't be much drop between the underhood fuse box and battery. What you're really worried about is boiling the battery though, so measure there if you want to be sure. 13.8-14.2v are nominal.

acey

No TPS connected. Re flash of the 1.41 firmware. Applying throttle slowly and still the same problem Battery still measures 14.5 consistently. How can I check that my alternator is working properly?
The car runs normal with stock ecu so that leads me to believe its a issue with the MS itself. Is there anything I could've soldered incorrectly to cause something like this?

gooflophaze

The 93 alternator is internally regulated, so no, it's not anything to do with MS. If you want to check the alternator, stick a multimeter on it on the battery and measure with something that's more or less known good. 14.5 isn't going to blow up MS.

I just looked at the video and your tune - you need to remove fuel. You're already rich and then you have a dramatic spike - you're drowning spark. If the video and log were taken at the same time, you need to see if you've set the wbo2 up correctly - MS is seeing 2 points richer.

Secondly - if the issue persists - tune the VR pots. I know you said you already have, but those are starting points. Turn them a half turn clockwise - if it gets worse, turn them a full turn counter clockwise. I had a 5000 rpm limit going off the suggested values, tweaked them a little bit more, and haven't touched them since.