Spark Plugs and TVIS issues

[mack 10]

Hey all,

Simple question, What is your opinion on the the best spark plug to run in a standard JDM 4age bigport.

Also

The engine accelerates great until 3000-4000rpm then it just makes noise. This leads me to believe that we are having a TVIS issue and the second set of runner’s arnt opening up. Anyone know more about what this could be?

Thanks Mike

[adam]

An easy way of telling if the TVIS is not opening up is to simply unplug it. This should leave it open whatever the revs are at. It should feel shittier down low (assuming it was working before) and then rev like normal.

If the TVIS isn't working, it's normally stuck open though. I haven't read anything about it being stuck closed.


As for spark plugs, I just use those Bosch items listed in their book for a 4AGE motor, hasn't cause me any problems so far.

[Rice86]

i ran some cheapy $4 NGK sparkies when i dropped my second engine in to get it working as such....forgot i still had em in, took it to the drift practice...was good..still did its job, but i wouldnt recommended it just cuz its cheapo and anything could happen

[skaney]

I had problems with expensive spark plugs..... I just run your basic bosch im not sure what exactly. My engine runs rich though so im changing them quite often.

[TE27]

what he said^^^^

if the TVIS is stuck open it will be giving you problems down low and ive never heard of it being stuck closed... but there is always a first.

have you checked the timing??

as for spark plugs i bought some expensive ones last weekend but i havent put them in yet, cant remember exactly but they were NGK and were platinum. ill let you know if i notice any difference in power/economy/anything at all

[NIZLAH]

your basic cheapo copper spark plugs give a better spark than most expensive plugs... the expensive ones just last a shit load longer... just a point of interest..

[Nikkojoe]

or it could be in limp mode

Does it hold constant throttle without missing heaps? If it misses when you hold the throttle at any position, its probably running in limp mode (which makes the car have lots of low down torque, then doesn't rev past 4000rpm).

[Jonny Rochester]

I want to learn more about limp mode. I have been hearing about it for years now, but not sure I have read any proper facts about it. When does it come on?

[Nikkojoe]

Usually when a vital sensor fails limp mode will be induced. Could be map sensor, ecu, sometimes igniter (though usually it would not run). On later model's with knock sensor, this can also trigger limp mode if the sensor reads a fault or the sensor itself is faulty.

[mack 10]

THIS MAN WINS! it was in limp mode. TVIS wasnt hooked up and the MAP sensor wire wasnt connected correctly. So yea ran pretty rich and didnt rev.

You win!

All fixed now and it goes like a rocket