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Discussion Starter #1
OK, so I've finally gotten all the wiring harness pieces I needed to try to get my R/T running and after installing everything it still won't run.

I've done a bunch of tests and everything looks good and I have fuel (55 psi on the rail) and spark (nice hot spark on all plugs firing them with the DRB). Upon further testing, I've narrowed it down to a really weird injector problem. When I use the DRB to test fire the injectors, it fires #4 when you tell it to fire #1. All injectors are opposite - 4 fires for 1, 3 fires for 2, 2 fires for 3 and 1 fires for 4.

I did the same test on my Spirit R/T and it fires the injectors correctly. The wire colors and SBEC injector pinouts are the same as the IROC's. I checked all the wiring on the IROC and it all flows correctly with no shorts found. I went ahead and swapped in another 93 R/T SBEC and it does the same thing - fires them in reverse!

Has anyone seen anything like this and the hundred thousand dollar question: what did you do to fix it?!?!?!?!

One other thing to note, even when each injector is firing, they barely put out any fuel. You be hard pressed to notice that it even fired if you didn't have it within a half of an inch of something (like the intake manifold) so that you could see the slight mist of fuel that shows up on it. Is this normal, or should there be a much heavier, easily seen mist when the injector gets fired (DRB had fuel pressure up to 55 psi when injectors were being test fired). I guess I could pull the rail out of my Spirit to check, this but I figured I'd ask while I was typing.

Any help would be greatly appreciated.

Jon
 

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I dont know about the amount of fuel that should come out but if all of them are fireing the wrong cly then with the help of you scan tool just rewire so that they fire the right cly.
 

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Discussion Starter #3
Update on this . The injectors are definitely firing plenty of fuel. I had the rail out and tried turning the car over and a nice stream shot out of each one. I guess the DRB must only pulse them for a very, very brief pulse when it is doing the injector test. They are definitely being fired in reverse order (1 fires #4, 2 fires #3, etc.) when using the DRB though.

Another thing I found that is bizarre - in the 91 FSM, if you look at the spark plug wire diagram, it shows number 1 plug wire at the front left of the coil pack and the plug routing going clockwise (1,2,3,4) around the coil pack. The 93 T3 Diagnostic manual shows it as number 1 plug wire at the front right of the coil pack and going counter clockwise (1,2,3,4). What's up with that? Is one of my manuals wrong, or did Chrysler actually change the way the coil pack was fired/routed in 93?

If they changed the way they routed, then maybe they changed the way the injectors fired as well. However, all the injector wire colors and SBEC pin numbers are labeled exactly the same in the 91 and 93 manuals and my car has them just like the diagrams show.

I'm stumped. Anyone have a clue what the heck is going on here? I can post a picture of the spark plug routing pictures in the two FSM's if you guys want to see for yourselves.
 
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The FSM is wrong 91=93 all fire the same and wires are the same orientation on the coil pack. I have swapped out different year coils and run 92s and 93s off 91 SBECs they all fire the same.


Whats the story with the injector harness did you get a different one or something? Try swapping out the entire fuel rail,injectors,and injector harness from you Spirit. They wont be 895 injectors but they should run fine in the car.
 

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Sounds like the harness is installed backwards. Try reversing the order of the injector connectors.
 

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Discussion Starter #6
Hey Jackson - thanks for the reply.

When you say "the FSM is wrong", are you saying the 91 FSM is wrong or that the 93 T3 Diagnostic manual is wrong? I have the plug wires in my Spirit R/T hooked up the way the 91 FSM shows and the car runs fine. I tried wiring them both ways in the IROC and it didn't seem to make a bit of difference.

The injector harness is the stock injector harness that came on the car. It's in really good shape and is one of the few things that the mice/squirrels didn't eat before the car came to me. I put in a known good main harness from a 92 IROC R/T, as well as all known good sub-harnesses from a 91 Spirit R/T (the original 93 injector harness was the only original wiring kept). I wired in the 93 speed sensor wiring to the 92 main harness, but other than that I didn't change anything else on the main harness. I'm also using the original 93 SBEC, but have a spare 92 that I tried and it behaves exactly the same way as the 93.

The problem doesn't seem to be in the injector harness because I traced the signal all the way back to the SBEC, and when the OTC DRB tool is set to fire injector 1, the signal comes from the pin for injector 4 on the sbec (pin 13 - it should be coming from pin 16). Maybe my OTC is messed up?

I haven't tried firing the injectors on the Spirit to see if does the same thing, but I have tried using the 91 OTC program to fire the injectors in my IROC and it still fires them backwards. Maybe I should try firing the injectors on the spirit with the OTC tool to see what happens?!?!?!

What the heck, might as well - been at this for 2 FULL days with still no start. This was supposed to take 1 of my vacation days this week, but now I'm on day 3......:bang head!!!
 

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Discussion Starter #7
Sounds like the harness is installed backwards. Try reversing the order of the injector connectors.
Thanks for the reply, but the harness isn't backwards - the wire colors match the colors in the FSM and Diagnostic manual, and they also match the way the injectors in my Spirit R/T are hooked up and it runs fine. I also looked on Ralph Scott's RT site and every injector harness that I saw on that site is hooked up the same way too.

It would be really hard to switch them around anyway - I doubt I would have enough slack in the harness to reach the wiring for #1 all the way over to injector #4.
 

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OK, well, I just tried using the OTC to fire the injectors in my 91 Spirit R/T and it fired the correct injectors. I also manually made the scanner run with the 93 R/T set as the SBEC, and it still fired the Spirit's injectors correctly. So I don't think there's anything wrong with my OTC.

So now I'm really stumped. If just the 93 SBEC that I have was firing the injectors in reverse that would be one thing, but since both the 92 and 93 SBEC's are firing them backwards that leads me to believe that somehow something is wrong with the wiring in the IROC. I just don't know what wiring would cause something like this to happen. The signal comes out of the wrong pin on the SBEC - injector 4 pin lights up when OTC fires injector 1, so it can't be anything from the SBEC to the injector harness - can it? Is it possible that both SBEC's I have are f'd up?

This is bizarre and frustrating.
 

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Discussion Starter #9
Well, Kelly came over yesterday and after we did the headliner in his GLHS, we tried a SBEC from his 92 IROC RT. My OTC fired the injectors in revers on that ECU as well, so I'm pretty sure it's just my OTC doing something funky and not really anything wrong with any of the SBEC's I've tried. Kelly was going to go home and try his OTC on his IROC and see what happens, but unfortunately he wasn't able to fire the injectors with his OTC for some reason :)mad:).

One good thing - Kelly and I checked the cam timing, and sure enough it was off. We fixed it and tried firing the car again and it actually hiccuped a few times, but never started. So, while the cam timing being off was definitely adding to the problem, it doesn't seem like it was the entire problem.

Starting to think Kelly's words of wisdom may be wiser than I thought. His words of wisdom...."I'd a put a bullet in this one a long time ago." :(
 
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