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Injectors 2 and 3 not pulsing

Posted: Sun Sep 09, 2012 2:21 am
by LGT Kirby
Can't figure it out. They both give the start up initial pulse, then they stop, not continuing the rhythm like the other two injectors. Tested everything possible. Hoping someone can tell me from experience that I put something in backwards or something.

Let me know ASAP!!

Thanks!

Re: Injectors 2 and 3 not pulsing

Posted: Sun Sep 09, 2012 3:06 am
by PhyrraM
Swap injectors and see if the problem follows the injectors. If it does, replace the injectors. If the problem is still #2 and #3 then check the harness, connectors and ECU.

Re: Injectors 2 and 3 not pulsing

Posted: Sun Sep 09, 2012 3:10 am
by LGT Kirby
The injectors worked fine prior to the rebuild. I've gone back and redone all wiring ive done for the 5 speed swap with no avail. Something is telling the ecu to drop fuel to those two. When you disconnect the battery and drain the charge, then reconnect and start, it almost fires off, then the ecu gets a signal from somewhere telling it to cut fuel to those cylinders, and it does out. No codes in it either.

Re: Injectors 2 and 3 not pulsing

Posted: Sun Sep 09, 2012 5:00 am
by PhyrraM
I find it unlikely that the ECU is dropping only 2 cyls. I can't think of a single scenario where that would happen.

It is possible that the output transistors are overheating after the first few fires.

Have you tryed another ECU?

Re: Injectors 2 and 3 not pulsing

Posted: Sun Sep 09, 2012 5:49 am
by LGT Kirby
No I haven't.

What I've done as for wiring mods are only bypassing the neutral lock, wiring the reverse lights, and snipping the mt/at identifier. I've reconnected the snipped wire and got nothing. I've reinstalled the TCU and got nothing. Tomorrow morning I will be looking at the neutral lock by pass to see if wiring it that way (where the car can start without the clutch engaged) is causing an issue. Other than that I am stumped. Keep in mind everything worked before I started modding.

Re: Injectors 2 and 3 not pulsing

Posted: Sun Sep 09, 2012 6:01 pm
by LGT Kirby
$100 to the person who makes this thing start.

Re: Injectors 2 and 3 not pulsing

Posted: Sun Sep 09, 2012 8:29 pm
by LGT Kirby
Just tried a different ecu. Wasn't it

Re: Injectors 2 and 3 not pulsing

Posted: Sun Sep 09, 2012 9:37 pm
by Legacy777
Check to make sure that you have 12v at the injectors all the time and it's not cutting out. If you have voltage, check the wiring from the injectors to the ECU to make sure it's good.

Re: Injectors 2 and 3 not pulsing

Posted: Sun Sep 09, 2012 9:56 pm
by LGT Kirby
12v is good. Wiring is all good.

Re: Injectors 2 and 3 not pulsing

Posted: Sun Sep 09, 2012 10:11 pm
by Legacy777
Have you put a multimeter on the wiring and verified it's 0 ohms all the way back to the injector ECU pins?

If you've done this, and swapped out ECU's....I'm kind of at a loss without some additional information/testing.

Re: Injectors 2 and 3 not pulsing

Posted: Sun Sep 09, 2012 10:14 pm
by LGT Kirby
0 ohms? I got a steady 11 on all of them.

Re: Injectors 2 and 3 not pulsing

Posted: Sun Sep 09, 2012 10:20 pm
by Legacy777
11 volts?

It sounds like you are checking voltage at the injectors. That's good. However you need to make sure the wiring from the injectors to the ECU is good. To check continuity of the wire and make sure everything's good you need to check the resistance. 0 ohms indicates the wire is good and there's no issues. You will need to put one end of the meter in the injector wire that doesn't have 12v on it, and then put the other end in the ECU pin for that particular injector to test for continuity.

Re: Injectors 2 and 3 not pulsing

Posted: Sun Sep 09, 2012 10:46 pm
by LGT Kirby
11 ohms on the injectors themselves. I tested continuity from the injector wire to the bulkhead harness behind the battery, that checked out. Will check to the ecu as well. The thing that weirds me out is when hooking up my bulb to the injector harness, the two injectors not pulsing correctly on their stroke both have the initial "all 4 injectors pulse to try and start the engine", then they stop, while the other two are still pulsing when they're suppose to.

Re: Injectors 2 and 3 not pulsing

Posted: Tue Sep 11, 2012 4:04 pm
by LGT Kirby
Bump this 1 week till I leave.

Re: Injectors 2 and 3 not pulsing

Posted: Wed Sep 12, 2012 5:32 pm
by Legacy777
Did you check the wiring to the ECU?

Re: Injectors 2 and 3 not pulsing

Posted: Wed Sep 12, 2012 6:37 pm
by LGT Kirby
Yes, got nothing.

Re: Injectors 2 and 3 not pulsing

Posted: Wed Sep 12, 2012 8:48 pm
by Legacy777
What do you mean you didn't get anything, please clarify? Did you not get any continuity between the connector in the engine bay and the ECU pins?

Re: Injectors 2 and 3 not pulsing

Posted: Fri Jun 07, 2013 12:00 am
by free5ty1e
I think we have the same problem - just after a timing belt replacement. My thread (just started):
http://bbs.legacycentral.org/viewtopic. ... ng#p408785

Could it be the cam or crank sensor causing this for us? Anyone know which controls injector firing...?

My car's stuck at the mechanic's shop until this gets figured out... yikes

Re: Injectors 2 and 3 not pulsing

Posted: Fri Jun 07, 2013 9:04 pm
by free5ty1e
Just because I like to see things resolved, especially when I'm looking through posts and find something similar to my problem but there is no solution in sight.....

See my original post here - http://bbs.legacycentral.org/viewtopic.php?f=19&t=52068
...it was my ECU.