Hi, I have a 94 FDR2 with all of the usual mods inc IRP fuel and ignition system, sequential stock turbos.
My problems began when I changed out the coil packs and the IRP fuel system 750cc and 2000cc. When I was removing the stock injectors one of the diffusers fell apart and went down the intake, that resulted in removal of the turbos and discovery of severely cracked and destroyed exhaust manifold. At that time nobody had and replacement turbos but I was able to locate a JDM set for a 93' that was in great shape so I installed the turbos and proceeded to start the car up. it ran Ok but would not make any boost above 4000, secondary turbo not kicking in. I had previously modified everything to a streamlined sequential and it has previously made 14 lbs with the old turbo setup. I took it to Pettit and he determined that the turbos were damaged. At that point I was selling my home in Florida and moving to Daphne and the car was driven to Daphne and put in storage for 3 months, while I was waiting for new house to be done. I was having some other issues with the car so I decided that I would install a new Mazda engine harness. The car drove from storage to new home and a couple of other times until I decided to install the new harness. I was not yet concerned about the turbos so only swapped the harness. Now I don't have any spark!
The Apexi had lost its previous tune so I had to input the new injector specs but do not see any thing in settings that would affect the ignition. I installed the old ECU, car would not run but it did have spark so I think the harness is probably OK. What am I missing here? I don't recall doing anything in the Apexi to compensate for the IRP coil pack, it started up and ran fine back then.

 

Since you changed so much, it is almost like an engine rebuild.
Thus you can not easily localize the problem to one area.
You will have to check every thing but you can break it up into different functions.

Electrical problems seem to be your #1 problem to solve first.
I would start with the new engine harness. Start with it's connection to the ECU. Most cars had a recall jumper harness added inside the car where the main harness connects to the ECU.
It's purpose was to add a new relay to engage the cooling fans for post engine shutoff cooling where the fans would run for 10 minutes.
The new harness's come with this integrated. Thus the old jumper was no longer needed. Make sure you did not somehow reattached it. You should also have the little black relay located near the ecu.
The unused single female black spade connector near the ECU is used by many of us as a manual controlled fan speed switch. When that connector is grounded, the cooling fan speed will increase by 1 speed.
Test this out. No fan then becomes speed 1, 1 becomes 2. 2 becomes 3. Leave it grounded when the engine is turned off and if the engine had been running long enough (? on time), the fans will run for 10 minutes even if the engine is not really hot.

Check that the ground connectors near the ecu are grounded. I think there are 2, I have not work on that area in many years so my 77 year old mine is fuzzy about it.
Next pull the intake manifold and check all harness connections there for the injectors, ignition, turbo control etc.

Keep on going.

 

This one turned out to be easy, I spoke with Dale and he looked at his Fd and verified my crank pickups were backwards. Strangely enough after rectifying that it started right up.
I still have a boost problem but things like the IAC and low coolant light are working correctly and I think the $1000 for the new harness was money well spent.
Dave

 

One crank and its connector were marked with a white paint on my FD. Even the new wiring harness that I installed after 5 years was marked as such.
Maybe you missed the obvious!

 

I did miss the obvious! If there are 2 ways to do something I will always choose the wrong way first!

 

I read somewhere that the JDM turbos have flow restrictors analagous to the inline pills on US cars integrated into one or more of the nipples on the actuators, and that if you don't drill them out you wont get full boost. I can't remember the details but if you search around you may find what I'm referring to. (WARNING <--- No0b)

TB

 

Thanks for that info, that may be exactly what is going. These turbos are very low miles and appear to be in great shape, I will research the pill issue.