A while ago my Hilux had a problem. When the engine was under load
under 1,400 RPM it had a slight misfire. The moment the revs went
over 1,400 it was running perfectly and performed as normal.
I was preparing for the worse. Some suggestions of the possible
cause included injectors, cracked head, burned valves, etc.
Luckily I phoned our Hilux
guru, Allan, first. He told me to start looking at the plugs
and plug leads first before looking at anything else. He said that
he have not replaced injectors on a 3RZ yet, so the possibility
of it being the injectors is very small.
I decided to start at the plug leads. I saw a post on the forum
where Eric (Family Dog) gave the specs for the resistance of the
plug leads. I decided to measure the resistance of the plug leads
to see if one is faulty. Because I was not sure how to measure the
resistance I phoned Eric. I explained to Eric what the problem was
and he informed me that his 2.7 Single Cab did exactly the same.
He told me that the suppressors on the end of the plug leads were
dirty, he cleaned that and the problem went away.
So I decided to start there and see if it helps.
First I had to remove all plug leads.
If you tried to remove the plug leads on your 2.7 Hilux you would
have noticed that the air intake pipe is in the way and you will
find it hard to remove the plug leads for plugs No 3 and 4.
The easiest way to do this is to remove the plug lead at the coil
end first, then pull it from under the air intake pipe and only
then try to pull it from the plug.
These plug leads are very expensive (A huge rip-off if you ask
me) so be careful and treat them with respect.
NETHER pull it on the wire, always pull on the fitting.
If you are not sure where which plug leads goes, mark them before
you take them out. They should be marked.
To remove the wire from the coil end, first push the fitting down
slightly, then pull the clip towards you. Look at the picture below.
First press down the fitting as shows at No 1 below. Then pull the
clip towards you slightly and the clip will be released. Move the
fitting up so that the plug lead is exposed. Now grab onto the rubber
fitting shown at point 2 and pull it upwards in order to remove
the plug lead from the coil. Remember not to pull on the lead.
Now take the plug lead out from underneath the air intake and then
pull the suppressor from the spark plug. Again pull on the rubber
molding as pointed out at point A below, nether pull on the lead
Look at the open end of the suppressor, you might see that the
inside of the opening is black. That is the debris which causes
I used a cloth and screw driver to clean it. I wrapped the cloth
around the screw driver. I sprayed some "spookpis" (Q20
or Spanjard) in the suppressor. Then put the screw driver point
in and turned the screw driver. I repeated this process a couple
of times until it was clean.
Do this with all 4 suppressors.
Now you can just put it all back. The plug leads should be marked.
If not, you will note that No 1 and 4 goes on the coil closest to
the radiator and 2 and 3 on the other coil. No 1 cylinder is the
one closest to the radiator and No 4 is the one closest to the cab.
When you put back the lead on the coil side, first push in the
rubber end and make sure it is in all the way, then put over the
clip and make sure it clips in properly when you push it.
In my case this solved the problem. Thanks Allan
If this does not solve your problem you can replace the plugs,
if that does not solve your problem replace the plug leads and if
that does not solve your problem seek professional advice or ask
the friendly guys on the forum.