toyota previa 2.4 engine dead missfire

Ask for and share advice on using the PicoScope kit to fix vehicles here.

toyota previa 2.4 engine dead missfire

Postby evanlip » Mon Dec 29, 2014 10:14 am

hi,i have a toyota previa 2.4L engine came in with a dead missfire.
the other workshop already put a set of new ignition coil,but the car is still missfiring.
so my first step is to hook up my scope,
i checked the power feed,trigger signal,primary current ramp.
but i found that the current was extremely low,and the power feed voltage drops when the trigger is on.
it can hardly start the engine when the engine is hot,but even if we cold start the engine,the missfire will slowly coming and getting worse and dead.
i have few captures here.
acr30 ignition feed current bad.psdata
(443.34 KiB) Downloaded 155 times
Posts: 12
Joined: Sat Jan 04, 2014 1:11 pm

Re: toyota previa 2.4 engine dead missfire

Postby AuthorMike » Tue Feb 03, 2015 10:25 am


I realise this was at the end of December, but did you get any further with it?

I see the file has been viewed 40 times, and while members may not have been able to assist I am sure we would all like to know if you were able to diagnose this any further?
Mike Valentine
Technical Author @ Pico Technology UK
Pico Staff Member
Pico Staff Member
Posts: 294
Joined: Mon Jan 31, 2011 11:22 am
Location: UK

Re: toyota previa 2.4 engine dead missfire

Postby Fat Freddy » Sat Feb 07, 2015 12:13 pm

My thoughts on this are...... Poss bad connection. Incorrect set up ID. The gnd side has a poor connection. Bigger voltage drop on pwr supply = better amps???? Just a thought.

Why lack of response. I think forum set up needs addressing. Tom's Auto Nerdz is a excellent example. Members feel like they are part of a community. This forum is a cruise by forum. Not intending to offend Mike but a revamp could get a ball rolling. Europe needs a Auto Nerdz. AN is a well laid out forum.

User avatar
Fat Freddy
Zen Master
Zen Master
Posts: 267
Joined: Fri May 04, 2012 4:52 am

Return to Diagnostic discussion

Who is online

Users browsing this forum: No registered users and 0 guests