:::RHMT::: Real Home Made Turbo

General Category => Engine Management => Topic started by: TTC on October 03, 2010, 03:44:38 PM

Title: PW's being dropped:
Post by: TTC on October 03, 2010, 03:44:38 PM

It seems im  dropping pulsewidths and im unsure why. My best guess is that the megasquirt ecu is not receiving enough constant voltage.  Underload the ecu is seeing at times 11.1v or so and thats when it drops. But on avg id say voltage under heavy load is around 11.3-11.5.

Should I wire the ecu directly to the battery or fusebox?   

PS: Does this have anything to do with batt compensation?

Title: Re: PW's being dropped:
Post by: Ntrain2k on October 03, 2010, 04:37:05 PM

Pretty sure the MS requires a dedicated 12+ and - on the battery for reasons like that.

Title: Re: PW's being dropped:
Post by: sewell94 on October 03, 2010, 11:01:06 PM

This doesnt have anything to do with the battery comps.

The ecu needs to be on a fused circuit.

What voltage is everything else in your car seeing? You should be seeing low 13's when the cars running.

Title: Re: PW's being dropped:
Post by: TTC on October 04, 2010, 08:23:25 AM

Its on a fused circuit to at the fusebox. But the same circuit IIRC might be powering the engine harness. I'm pretty sure the rest of the car is in the 12s but not 13s.  IT has a brand new alternator too, 80amp which is a 20amp upgrade.

Title: Re: PW's being dropped:
Post by: Joseph Davis on October 04, 2010, 09:34:10 AM

Are you on a brand new alternator, or a mexican reman using china parts from the local Advance/Pepboys/Autozone/O'Reilly crap parts wholesaler?  There is a difference, and a bad alternator is one of the things that will cause voltage to drop especially during a pull.

Toyota wiring is garbage.  You suffer with it like a helpless victim, or you do something about it.

If the datalogs aren't being interrupted and you are actually logging injector pulse shutting off... it may be battery voltage related, I've minimal relationship with MS so IDK if they'd do that... I'd look at something triggering a fuel cut/etc when that happens.

Title: Re: PW's being dropped:
Post by: TTC on October 04, 2010, 10:03:33 AM

Its a meximan bosche alternator lol .. Voltage with old oem alt was usually pretty low too. I'm thinking somewhere in shitty MS code there is a problem. It would seem like boost cut is coming on 5-10kpa early or something cause it doesnt happen at lower boost levels.  Toyota wiring sucks ass, next year ill make my own harness and be done with it.

The logs aren't interrupted, and its not reseting. Its actually a dip in pw down to like 0 for a sec then back up to normal.

Title: Re: PW's being dropped:
Post by: Joseph Davis on October 04, 2010, 11:30:47 AM

So you need to do work.

Title: Re: PW's being dropped:
Post by: Ntrain2k on October 04, 2010, 06:07:24 PM

Run it straight off the batt with a fused +12 and a dedicated ground.

Title: Re: PW's being dropped:
Post by: Aero on October 05, 2010, 07:32:23 AM

Sounds like a config problem to me, but fixing your wriring issues should be a priority anyway.
Post your msq.

Title: Re: PW's being dropped:
Post by: TTC on October 05, 2010, 08:30:17 AM

Says uploaders full.

iirc:

ms1 vs 3.0
Hires G
sns edis

I can email it to you if you want