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12HT Misfiring???
Posted: Tue Oct 25, 2005 8:33 pm
by Homer
I have a bought a HJ61 with 12HT originally as a donor but may end up keeping it....
anyway the engine is misfiring appears to be number 1 cylinder ...process of elimination i.e. loosening each injector pipe one at a time makes it run very rough but No 1 stays the same
I have had the injectors independantly tested ($20 at Diesel Specialists Hamilton FYI) and they reported opening pressures are all low but nothing bad enough to cause the miss
I also swapped with No 2 fault stays on 1 and turned it over with both 1 and 2 injectors spraying in the air .... both OK so pump seems OK
Valve adjustment also OK
now I am looking for probable causes and I don't have a compression gauge that will do 500psi (anyone know where I get loan one?)
What else could it be ? any ideas ?
Scott
Posted: Tue Oct 25, 2005 10:16 pm
by CheesePony
Not the pump itself is it ? :(
Posted: Wed Oct 26, 2005 6:36 pm
by Homer
Don't think so I had the number two injector connected to Number one port spraying into the air ....nice pattern looked OK
Desperately need a compression tester!
Posted: Wed Oct 26, 2005 11:07 pm
by Shadow
Homer wrote:Don't think so I had the number two injector connected to Number one port spraying into the air ....nice pattern looked OK
Desperately need a compression tester!
you can get compression testers from supercheap for about $20
you will need to get a fitting to go into your glow plug hole.
THis is a fine metric thread. No idea where to get this adapter, maybe toyota?
Posted: Thu Oct 27, 2005 12:37 am
by KaMo
12HT does not have glow plugs
Posted: Thu Oct 27, 2005 1:20 pm
by joel HJ60
KaMo wrote:12HT does not have glow plugs
Hey yeah he's right! I still havn't got my head wrapped around that concept of no plugs. Can someone explain it better to me please?!?!
Posted: Thu Oct 27, 2005 1:53 pm
by +dj_hansen+
Pretty sure they use a glow screen in the intake manifold... kinda like a toaster i think...
Dumbdunce, as per usual will have all the info
Or are you refering to diesel engine vs petrol with spark plugs?
Posted: Thu Oct 27, 2005 2:22 pm
by Den.R
It is because the 12H-t is direct injected as opposed to the 2h which has the injectors spraying into a pre-combustion chamber.
Posted: Thu Oct 27, 2005 9:31 pm
by Shadow
KaMo wrote:12HT does not have glow plugs
your right
for the 12HT you have to take your injectors out and get an adaptor for this thread.
Posted: Thu Oct 27, 2005 10:59 pm
by KaMo
Shadow wrote:KaMo wrote:12HT does not have glow plugs
your right
for the 12HT you have to take your injectors out and get an adaptor for this thread.
I doubt you'll find a thread in there either...pretty sure they're a straight bored hole with a seat in the bottom for the washer.
Posted: Thu Oct 27, 2005 11:41 pm
by Shadow
KaMo wrote:Shadow wrote:KaMo wrote:12HT does not have glow plugs
your right
for the 12HT you have to take your injectors out and get an adaptor for this thread.
I doubt you'll find a thread in there either...pretty sure they're a straight bored hole with a seat in the bottom for the washer.
how are the injectors held in, magic?
Posted: Fri Oct 28, 2005 12:11 am
by joel HJ60
+dj_hansen+ wrote:Pretty sure they use a glow screen in the intake manifold... kinda like a toaster i think...
Dumbdunce, as per usual will have all the info
Or are you refering to diesel engine vs petrol with spark plugs?
Is there something that heats the air up to high temp for ignition instead of the plug?
Posted: Fri Oct 28, 2005 12:16 am
by Shadow
joel HJ60 wrote:+dj_hansen+ wrote:Pretty sure they use a glow screen in the intake manifold... kinda like a toaster i think...
Dumbdunce, as per usual will have all the info
Or are you refering to diesel engine vs petrol with spark plugs?
Is there something that heats the air up to high temp for ignition instead of the plug?
yeh a glow screen on the inlet manifold.
Posted: Fri Oct 28, 2005 1:39 am
by KaMo
Shadow wrote:
how are the injectors held in, magic?
Depends what space cakes you have been eating i guess...
There is two long studs per injector that are fixed into the head. Then one lug on each side of the top of the injector with a hole in it. You slide the injector into place...the studs pop through the lugs...and you tighten them down...pretty simple!!!
Can't say i have seen an injector that screws into place before...
Posted: Fri Oct 28, 2005 1:41 am
by KaMo
dbl post removed
Posted: Fri Oct 28, 2005 2:12 am
by Shadow
KaMo wrote:Shadow wrote:
how are the injectors held in, magic?
Depends what space cakes you have been eating i guess...
There is two long studs per injector that are fixed into the head. Then one lug on each side of the top of the injector with a hole in it. You slide the injector into place...the studs pop through the lugs...and you tighten them down...pretty simple!!!
Can't say i have seen an injector that screws into place before...
the 2H injectors screw in to place.
The toyota manual says to use the SST Guage Adapter for compression testing the 12HT which is fixed in the injector nozzle holes.
SST 09992-00023
Easiest way would be to just modify an old injector if you can get your hands on one. Drop the nozzle off the end of it and then the fuel lines should be a fairly standard attachment that you should be able to get an adaptor for.
Toyota would probably want a wad of cash for something which is probably exactly this.
Posted: Sat Oct 29, 2005 5:44 pm
by Homer
Yep that is the second part of my problem getting hold of an old injector to make the adaptor
the first being.... for some reason you need to multiply the price by 10 to get the gauge from 300psi to 500psi...can't figure that out??
supercheap have one $29 I actually bought and then took it back ... only goes to 300psi
coventry auto parts have a few of them but they start at $280
can't find one at a hire shop either.... I need put it back together and take it some where to get tested I think!