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View Full Version : KA24DE - #2 Injector Not Sealing


lbs_ft
06-09-2011, 08:32 PM
Hello all, once again I come to you in need of help...

I had this problem with my last twin cam, and this is the second time I've had this same issue with the newly rebuilt motor, with only 1300 miles on the odo. The #2 injector won't 'seat' correctly, and, therefore, the motor will only run on 3 cylinders. I know this is absolutely terrible for the motor, it must put a lot of unnecessary strain on a lot of parts, so I always aim to fix it asap.

Seeing as this is becoming a common occurrence , I've come to a couple conclusions already:

1) The wiring harness/ECU is fully functioning, I used a diode to test, and all 4 injectors are receiving power correctly.
2) I have spark on all 4 plugs.
3) Compression is 190 across the board, perfect.
4) All 4 injectors DO fire correctly.

So, to provide basic information: car is a 1990 coupe, harness is 93 twin cam, engine is 96 KA24DE. Last motor was a 93 KA24DE, and I'm re-using the fuel rail from that engine.

So here's what happens: driving fine, all of a sudden, huge drop in power, car smells like gas, exhaust sounds like a boxer motor. Pull over, pull #2 spark plug boot, no change in shitty idle. Switch #1 and #2 injectors, car fires up after clearing the flooded cylinders, runs rough for a couple seconds, evens out, runs perfectly fine again. Eventually it happens again, like 500+ miles later.

SO! My question is: what do you think the issue is here?

Should I replace my fuel rail with another from a junkyard twin cam?

Should I buy new injectors? ($$$, very expensive so I want to avoid dumping money there when mine still work)

How do I clean my injectors? Keep in mind, these are the same injectors that were powering my last twin cam when it committed suicide, and I've never cleaned them because I don't know how.

How can I make the injector 'seat' better in the rail? When I pry the injector out, you can see and hear it decompress, and its a bitch to remove, so I know the outer o-ring is good. Any way I could replace the inside o-ring or something?

Any and all help is graciously accepted, I just want to fix this for good and not have to worry about it again.

I can answer any questions you guys have, and I'll add information as I think of it or as it comes to me.

Thanks again!

meen13
06-09-2011, 09:12 PM
If you haven't cleaned the injectors maybe research and do that first before anything.
Better to be safe then sorry

theboy
06-09-2011, 09:17 PM
time for injectors, and while your at it, pull the rail and fpr. clean the shit out of the rail and either clean or buy a new regulator. Its weird that you can swap 2 injectors and all of sudden it works just fine though? Is it the same injector that goes bad, or is it always the #3 injector (no matter which one you have in the hole) that goes bad? If the o-rings were bad, it would spit gas out all over everything as soon as the fuel pump built pressure.

Tantwoforty
06-09-2011, 09:27 PM
junkyard, go pocket like 10 injectors and try them all, get a new oring kit..
worked out for me and its nice to have a pool of extras.. and its 2 bucks.. they are in the altama aswell.

check your fireing order and and your timing your cap and rotor and wires and plugs make 100 percent sure you have the wires in the right place.. not to doubt that you messed something that dumb, but i mixed up my wires in the dark once, and i had a leaky lower oring.. and those 2 things combined had me sounding like a WRX and shooting 10 foot flames with no power. so something to think about..

so,
-new orings
-try some new injectors
-check timing
-check wires-
-check cap
-check rotor
-check plugs
-check fuel pressure

you can always install the injectors to the rail and crank the motor and see if they spray, although it sounds like you have done that. it may help you...

check some of that stuff and get back to us

lbs_ft
06-09-2011, 09:29 PM
You can hear a definitive loss of pressure when you pry the injectors out, so the outer o-ring is sealing fine. I can put any injector in the #2 slot on the rail, and they're bound to fail eventually. But as soon as I swap another on in, #2 cylinder is back up and running, and the injector that was previously in the #2 slot will power any other cylinder

#2 injector slot is the issue...

lbs_ft
06-09-2011, 09:30 PM
junkyard, go pocket like 10 injectors and try them all, get a new oring kit..
worked out for me and its nice to have a pool of extras.. and its 2 bucks.. they are in the altama aswell.

check your fireing order and and your timing your cap and rotor and wires and plugs make 100 percent sure you have the wires in the right place.. not to doubt that you messed something that dumb, but i mixed up my wires in the dark once, and i had a leaky lower oring.. and those 2 things combined had me sounding like a WRX and shooting 10 foot flames with no power. so something to think about..

so,
-new orings
-try some new injectors
-check timing
-check wires-
-check cap
-check rotor
-check plugs
-check fuel pressure

you can always install the injectors to the rail and crank the motor and see if they spray, although it sounds like you have done that. it may help you...

check some of that stuff and get back to us

Alright, got a checklist, devoting this weekend to it. I'll report back as I run through everything

Tantwoforty
06-11-2011, 05:35 PM
oh, maybe try another rail to...
if you were local id give you one lol