Toyota vvti

lilymunster, Aug 2, 9:22pm
Hi, any ideas please on why the engine misses underload (going up hill etc) The coil packs have been checked and are good. The petrol is not old and the tank is half full. Any help would be appreciated ! Thanks
pandai, Aug 2, 9:45pm
Check (and clean and tighten?) ground points and electrical connections.

I had a misfire that only happened above 4500rpm and that was because of a loose negative terminal on my battery. Took a short while to figure that one out.
lilymunster, Aug 2, 10:10pm
Ok thank you.
pandai, Aug 2, 10:16pm
Also going to assume that because the coil packs were checked the plugs have also been inspected
kazbanz, Aug 2, 10:20pm
Check the AFM and give the throttle body a huck out.
lilymunster, Aug 2, 11:23pm
Yes the spark plugs have all been replaced. Thank you pandi and kazbanz for your suggestions.
intrade, Aug 2, 11:38pm
how much do you know?

because check this that and the other means squat if you dont have advanced engine managment training . You dont unblolt things and take a look that was 40 years ago you need a factory level scanner and knowing what you are doing with it or a graphing oscilloscope to test components correctly
intrade, Aug 2, 11:43pm
when i seen the title vvti = variable valve timeing
the valve adjust at higher rpm. i can comand the variable valve on and off with my android phone and the aftermarket toyota factory software . if the actuator is not doing its job you can have missfire and power loss.
Toyota are no longer bullet proof and faults are just as hard to find as on holden astra fiat vw mitsubishi etc. you cant go its probably this that or the other like you could in the 1980s and 90s. these times are over since vvti started on toyota.
also i dont say your variable timing is faulty , i just say it can be a couse of loads for a missfire on toyotas
intrade, Aug 2, 11:46pm
how did they check the coil packs exactly ?
explain exactly how that was done?
lilymunster, Aug 3, 12:07am
I took it to the Toyota service agents, who put it on their computer, and said they couldn't find what was causing the miss, but we managed to get the check engine light off . That was $380. Then they said you should book it in for a service. that's why I replaced the plugs which did stop the miss at first. Drove well for two weeks. Now its started again.
kazbanz, Aug 3, 12:17am
Intrade Under normal circumstances I would agree with you.
BUT specifically with the Toyota VVTI engine cars I have found that cleaning the AFM and scrubbing out the throttle body is 9 times out of 10 the cause of a misfire. (those not caused by idiot groomers shooting 120psi jets of water into the plugholes)
The thing is that checking/cleaning those two items can be done with no major effort and the affect is immediately odvious.
lilymunster, Nov 25, 12:00pm
Great, thanks so much Kazbanz. I will get that done.