well hell, i'd be puttin that stock **** back in so i can actually drive the car that i just spent thousands on for a new engine... THEN worry about making the injectors/resistors work

 

Well I might have gotten mistaken posting here but the secondaries are low imp while the primaries are high imp.

I did this so later on I can drop in high cc injectors into the secondaries.

There's nothing stock about my car.

I have all TII components other than the NA interior harness. I've spent around 6k on this swap so far.

I know it would be nice to use the same injectors through out it but I don't have them right now.

I do have some low impedance 460's but then I have th rewire this harness once again.

I checked continuity through the resistor box and it was fine. SO I can only assume that there is a break in the 16yr old wire between it and the ecu plug or the plug pins aren't doing a very good job.

All of the injectors are known working ones. They have all been flow tested before installation and I saw them spraying with my own eyes last night.

It's that they aren't getting voltage so they don't spray.
I've swapped ECU's and it has still continued. Thus you must conclude it's the harness since the ECU and injectors have varied while the harness has stayed a constant.

I'll pull the harness again tingiht and uncover some more loom to see if discover a break in the wire. I might just cut length out and run new line to see if it does anything. If I ruin the harness, Oh well. I have one on it's way right now.

 

run some wires from somewhere near the ECU (or however far up on the wire you have continuity) straight to the injector just to see if it'll work.

just tap the wire, tap in an injector plug onto each new wire and plug that **** up. that way if it runs you will KNOW its the harness.

 

Digi, in a post about 10 back you said you put the resistors on the front & rear primaries, then in another you said the low impedance injectors were the secondaries, and I thought you had the 87 1/2-on ECU, which is the high-impedance ECU...

This means you must have the 86 to 87 1/2 low impedance ECU, right? Because if not, I'm thinking you put the resistors on the wrong pair of injectors. Am I making any sense, or just confusing you more????

 

The ECU doesn't matter/shouldn't.

Sorry if I'm coming off rude but this is starting to get to me.

I think you read my post about voltage.
I said that when I reinstalled the harness.
My secondaries saw 12v but the primaries saw only 1 volt.
Then the next day after not touching a thing it reversed it self and the Pirmaries saw 12v and the secondaries saw 1v.

Also,
Resistance has nothing to do with seeing 12v at the ECU. Pretty much there is a bad connection or something some where preventing contiuity.

Oh well. This is making me smarter in the end

 

Oh yeah and N333 is 88 TII ECU.
Which are almost always high impedance.

 

That's all right, you can be as rude as you want, I know what you're going through, and I would have been in a pissed mood a long time ago too

Now, go back to page 4, about 2/3 of the way down- you stated that "you installed the resistors on the primaries, pins 3C and 3E" (which are- I double checked)...I gotta ask this again- if the high impedance (11 ohm or so) injectors are the primaries, WHY do you have resistors on them? I know just above you said that you didn't have resistors on the primaries, so you must be confused somewhere- you're telling me two different things...

And resistance has EVERYTHING to do with voltage (once the circuit is completed), at the ECU, or any where else on the car, for that matter. Trying to teach a very well educated, 20 year experienced electrician new "Digi laws of electron movement" ain't gonna work for ya, lol...

Now, have you tried swapping the pairs of wires, just in case you accidently wired them wrong? Just trying to help, man....

 

ECU does not matter in terms of fuel injector impedence.
The wiring harnesses are different to accomodate stock built-in resistors for the earlier FC's.
You can swap ECU's from the different years, and everything will still work.


-Ted

 

Bah, I'll check that tonight.
There's always a chance I wired them inline wrong.

Although that might fry my low imp secondaries if I did do it wrong, right?

I'm not an electrical engineer but I know there is a correlation between voltage/resistance/etc.

I just meant that the ECU's don't matter in this situation.
Especially since the voltage decided to play around and show 12v on certain lines on certain days while others had 1v.

Even if I wired them in backwards it wouldn't explain why the harness decides to give all no or juice to the circuit.

 

YOu cant wire them backwards.. If it were possible, you could take the plug, unplug it, turn it around. it would still run.

FWIW, I messed up my first install of my resistors. Mistake #1, putting them in the engine bay..

 

J-Rat, have you been helping him? Did you double check the injector runs?

Digi- if you're getting 1v, that might as well be zero...there are two possibilities: 1) the circuit is broken somewhere between the main relay and that ECU wire (your theory, IIRC), and 2) if the plug is on the ECU while you're doing your readings, the ECU is grounding you out (the injector is energized)

 

my friend just got his enigne rebuilt and we put it and it startsup fine and does not flood but it sound like it is running on one rotor until like 2500rpm what can that be we checked all the injectors and put new plugs and check the timing this is a 90 turbo with new rotor housings but with s4 rotor with a street port

 

J hasn't helped me with this harness. It has all been done by me.

What I meant by backwards is Reistors on the wrong injectors.

I understand your second thought Wayne.
It's not energized though. If it were th injector woul d be open.
The inecjtors hold 38psi in the rail so I know they aren;t open or i would have seen it lol.

I'm going with broken circuit due to loose connection/plug or broken wire.

Oh well. It'll be checked tonight for continuity again.
Then a key on 12v test. Then pull it out and inspec the lines.

 

rx-7fc, please start another thread on your prob...

All right, Digi, let's stick with the open circuit theory for now, good luck, man, and keep us posted...

BTW, have you isolated & read out the resistors for the proper resistance? The big paper-wrapped ones can get burnt fairly easily...(you only have to remove the wire from one side of it to isolate it, then put the probes on either side of it)...

 

I checked them for resistance and their dead on. 10ish ohms each(tester is a little goofy so it may be off an ohm or two).

They are big resistors. encased in ceramic and a plastic rectangular shell.

Damn this thead has gotten big.

Might have to start a new one if the problem/anomaly persists.

 

Cool, so they're good at least...

Yeh, generally the very low resistance jobs will be bigger than the "kilo-ohm" guys...

Yes, it's gotten big, so let's hurry up & fix it!!!

 

All I have done was go to his house and do some quick testing (I couldnt stay long). Then I gave him some ECU/TPS tester lights because he didnt have them. I started the car and it ran fine, then I shut it down. Next time I went to start it, it started exhibiting all the symptoms that he is listing.

 

So is it one of those "starts great when cold, but won't start when hot" cases?

Did you read out any of the injector voltages at the ECU while it was running?

 

No, its a starts great when the moon is aligned with Venus, and doesnt start any other time...

And I was the one that initially started to blame the injectors. After the motor ran, the front plugs had slight carbon marks (indicative of combustion), and the rear ones had no such marks. I merely pointed C in the right direction, he took it from there.

 

Oh, and I performed a compression check. That seemed low, but nothing out of the ordinary considering its a fresh rebuild with almost no street time.

 

It seriously is connected with the movement of tides and the full moon and how many burrito's you've eaten within the last yea lol!

One day it runs absolutely perfect. Then 15 minutes later BAM! It drops fuel to the rear rotor.

It dies off and doesn't run.
Next week try it and it starts up on it's own. Runs a while then for no reason drops out.

Next week. Nothing won't start up.
Next week same thing.....
Next week Jrat comes and it kicks up by itself. Runs for like 5 minutes and we shut it down.
Won't kick back up.....

Me thinks vibration killed a connection.

 

OK another thought. Can some one direct me to the right section of the FSM or knows this plug?

It's the orange EFI to Interior harness plug.

It is
XXX___XXX
XXX_X_XXX

Or something VERY similar to this setup.

All of the injectors toned out to one of these pins(I forgot which one/ones).

This is the only part of the harness I cannot determine what pin is what.

Once I find that part of the FSM I can understand why it's connected to there. Is it the power source for them?

 

DAMN IT...I just wrote a long *** novel for you, Digi, and it disappeared into cyberspace...That's it, I'm double posting everything from now on...****....

I reread everything in the thread again, and came to the conclusion you're probably right about the harness, Digi. I think it's getting hot after running, and a weak electrical connection somewhere is breaking, and it's getting progressively worse on ya...

Visually recheck all the wiring run between the rear primary connector and the ECU (and make sure it doesn't run through that resistor pack- I actually read TWICE in the thread where you said "I wired the resistors to the primary injector", so do me a favor and double-check that for me, and for you)

Make sure your solder connections are clean & strong- if you used a lot of flux during soldering and didn't heat it up enough to "float" the flux, it could be causing your bad connections...

 

Also, take a look at page 50-29 in the FSM wiring harness, down in the lower left corner- that the plug you're looking for?

If you have to, run a new wire from the injector to the ECU, at least a "temporary" one for troubleshooting...

If it is a bad wire, you ought to find it while running her, with the meter probed to the rear primary input at the ECU. You'll be cruising along at 10 volts or whatever, and it'll just drop to 0 on ya, if it's the wiring....

 

lol this is where the funny **** kicks in.

I'm getting voltage through all wires now!!!!!

It fixed itself?!?!?!?!?!!!!

So I can only guess it's some really shitty connection some where. I mean, The only thing I've done is jiggle some wires while working in there.

So I'm debating if I should do a temp install and try and drive with it.

I fully plan to rewire the harness coming. I am going to go through the harness with a fine tooth comb. Every solder is going to be damn good and shrink tubed.