I have a 1993 LT1 Engine and I am putting it in a Jeep, I have had the Chip burned for Off-Road, no Emissions, no Trans, no VATs... I also bought a new harness from Fuel Injection Specialties and added a Delteq Ignition to help keep the water from giving me problems.
So the problem is, I have the Delteq installed and the new harness on the engine, new chip in the ECM and I am trying to get this to start. It will start then quit, start then quit. The injectors fire a prime (choke) into the engine to start it then don't pulse any more. The engine will run on Carb cleaner and when I plug in the old module and coil it "appears" to work (injectors pulse and coil sparks), but I don't have the plug wires to run the engine on so I am not 100% sure. The LED on the Opti-Direct works the way it should, the Coils all fire, the Fuel pump (new) works at 45 PSI, all fuses are good, all sensors are good (except for the missing oil pressure switch, which I am told will not affect the running of the engine when it is not plugged in), I have checked all the connectors and have found a couple wires that were not pressed in all the way, and I have not run this engine before this.
I have spent hours on the phone with Pete at Delteq, and Vince at F.I.S. and they have been unable to find the source of my problem.
It would seem that there is no reference signal getting to the ECM from the Opti-Spark, but the LED is indicating that there is. (In my serching this site today I read that some believe that the LED can light up even with a bad Opti-Sensor, this is a possibility for my situation, but I don't want to run out and spend $400.00 on a guess when the problem may be much more simple than that.)
One last thing, I am getting a DTC46 - Faulty circuit leading to the VATs or to the ECM - or something like that. No one can explain the DTC either.

Is there anyone here who has has this problem and knows how to fix it?
I will be grateful for any help here.
Sorry this is so long, I tried to provide as much detail as possible.
Chris R.

 

I think you found the answer. Apparently someone DID NOT remove the VATS function. since a 46 is the lack of signal between the TDM and the PCM. I have never had any function removed with programming but I would think that if a function were removed, it wouldn't initiate a DTC associated with it.

The TDM is not signaling the PCM as it should and therefore the PCM is shutting down the injectors. That is text book DTC 46. The signal that is in error is the fuel enable signal from the TDM to the PCM red connector pin 25. (sorry if the pin outs are wrong, using a 94 book since I don't have a 93 book)

The TDM is not setting the proper condition to the PCM. Is it because you no longer have the TDM connected when you moved the engine or is it perhaps the fact that the Jeep doesn't have the contacts in the ignition switch to read the key? If that is the case, a simple placement of a resistor between B8 and B7 of the TDM connector will cure that problem. If you still have the original key from the car the engine came from, that would help to figure out the resistor size quickly. Otherwise, it will take some time to try each value of resistor to find the correct one.

Good luck

 

I did ask Vince about the trouble code and he was not able to find a reason for the code. As for the steering column, this vehical doesn't have one yet and I don't have the stock column, the VAT module, or the key to go with them.
The next question I would ask, is if the ECM would still fire the Injectors to prime the engine if the Anti Theft Module was not sending the proper signal to the ECM? It was my understanding that it would shut down the Fuel pump too, and my fuel pump circuit is working fine.
I will call F.I.S. today and question them further about the trouble code and the possibility of the VAT not being properly removed.
Thanks for your ideas, any other thoughts?
Chris R.

 

VATS hasn't been taken out. You don't need a Camaro steering column for it to run.

 

VATS hasn't been taken out. You don't need a Camaro steering column for it to run.

I called them today and they never returned my call to tell me if their records show that the VAT was removed. They have been a good Company to work with, they have spent a lot of time on the phone with me helping to find my problem, got me some hard to find parts, prices were good too and have been very friendly, but the end result is:

1. My engine doesn't run
2. I didn't get all my parts
3. They aren't returning my calls
4. They can't seem to tell me anything besides "there is a problem there somewhere."

There is one thing that doesn't make sence. When I plug in the old coil/Module and I check the Voltage across the Negitive side of the Injectors (Computer controls the ground to fire the Injector) it shows current. I believe the engine would run on the original coil/Module, but will not run on the Delteq. ??? I don't have stock plug wires to plug into the Opti-spark, so I don't know for sure.
Should I go buy a set of Opti-spark plug wires to test this or should I just have them burn me a new chip to see if this fixes the problem. I don't plan to run the engine on the old coil/module, so it doesn't matter if it will or not except that the engine would still not run if the VATs is still in the computer.

Chris R.

 

Well 2 people have told you that the VATs is still present therefore do as I said and put the proper resistance across the 2 terminals of the TDM.

Do you even have the TDM any more? It doesn't matter what the cause of the dtc46 is, the result will be the same by the PCM. Remove the cause of the dtc46 and then continue to trouble shoot.

If you are getting spark at the plugs, don't worry about opti, wires or anything else ingnition related until you fix the 46.

 

No, I don't have the DTM.

How would a person go about figuring out what resistance to use?
There was a change between 93 and 94 with the ECM as you may know. The 94 is OBDII (PCM) and the 93 is OBDI (ECM). There are only 22 pins on the plugs going to my ECM, so it can not be pin 25, and my manual does not say what pin and what color connector it is/was, just that is was Dark Blue.
Since I have a new harness that was designed without the VATs, it isn't going to have a wire coming out for the DTM.
The truth is I really hope you are right, that they did screw up and the VAT was mistakenly not removed as they believe it was, because I am not really sure what else it could be.
Thanks for your input.
Chris R.

 

Your correct about the number of pins but not OBDII. OBDII wasn't used in F bodies until 1996 even though in 95 they have the OBDII connector.

Forget the resistor values since you don't have a TDM anyway.
Seems your only solution is to actually get the funtion removed from the programming. Wiring up another device would be difficult at best if the harness you are using removes the TDM.

To replace the signal going to the PCM from the TDM is too difficult since it is basically a square wave that varies in width and there is no information regarding what the waveform should look like.

Contact Ion (spelling) about your programming. Seems he should be able to remove the function.

Dave

 

I already paid someone to remove the VAT programming and they need to fix it. I just wish I had not already spent so much time trying to find the cause of my troubles.
I will know more tomarrow, thanks for the help.
Chris R.