1jz ecu IGF code 14 problem.

K

kas14slider

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May 18, 2010
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State College, PA
Hi guys, trying to figure out why my car is not firing correctly. Recently took the car apart and rewired it, mostly just shortening wires and removing unused circuits like abs, diag, ac, etc. Put the car back together and it turned on but ran horribly, like its only firing on a few cylinders. All the plugs were covered in so its getting fuel and all the spark plugs seemed to be firing. Got a code 14 so we checked the ecu IGF pin and it was only outputting 2v instead of 5v. It didnt matter if the IGF wire was hooked up or disconnected, still 2v at the ecu. Any ideas why the ecu is only outputting 2v at the IGF? I recently had it send to driftmotion for their recap service and it came back and it worked fine. Now after we took my car apart and put it back together, it is misfiring.

Is the ecu even supposed to output 5v on the IGF pin or is it the igniter that outputs 5v? Also, checked the TPS, MAP, IAT and Coolant temp sensors with the key on. TPS and MAP had 4.95v and the other two only had 2.6v. Should all of these be running off of the same 5v system in the ecu? Should they all have 5v with key on? I am just a little confused on how the 1jz ecu works.

Any ideas?
 
mkiiichip

mkiiichip

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Sep 10, 2007
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IGf is a signal wire from the ignitor to the ECU. This is what needs to happen to make the ECU happy.

1. ECU sends a signal to the ignitor to charge and fire a coil. (IGT circuit)
2. Ignitor charges and fires that coil (coil primary circuit)
3. Ignitor sends a signal back to the ECU, confirming that the coil was fired. (IGF circuit)


My guess is something is wrong with one of those steps.^

Oh and to see the signal properly, I would need an oscilloscope.
 
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mkiiichip

mkiiichip

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Also, the 2V reading you are getting. This might be the actual reading, or it could be an "average" reading your volt meter is coming up with. As the signal is a digital signal, from 0V-5V. like this,

digital-signal1.gif

Volt meters aren't much help with these kinds of circuits.
 
K

kas14slider

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May 18, 2010
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State College, PA
Well, all my coil electrical connectors were pretty crappy so we adapted some other plugs off of a toyota car, (I think they were from a prius). But we depinned the 1j ones and threw these on because they plugged right in to the 1j coils. Maybe these have something to do with it not firing right, but I highly doubt it.
 
K

kas14slider

New Member
May 18, 2010
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State College, PA
Ok. Sorry. JJ is right. I should have mentioned that my friend rewired my car for me. I didnt touch the wiring. Thats why i said wiring sucks. He has wired cars before but has never messed with a 1j so we are trying to figure out if its something he did or something is actually broken. It would be nice to not have to remove the whole harness again
 
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kas14slider

New Member
May 18, 2010
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State College, PA
Well after all the confusion it turns out the igf pin on the ignitor was a little bent so when the plug was on it wasn't making a full connection. So fixed that and the car sputtered to life after throwing tons of black smoke and running like crap from all the unburnt fuel. But after letting it run, we shut it off and when we went to turn it back on, we had to jump it because the battery was low. And after that it had its moments of idling and revving good but it also had a choppy idle and would sputter a bit. I'm hoping that getting a new battery or the old one recharged will make it run good because even when it was hooked up to the car we jumped it with it was putting a lot of strain on that car and maybe still wasn't getting good voltage.
 
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