1987 Mazda RX-7 GXL (turbo swapped)



Yesterday I swapped over a "new" unmolested throttle body to replace my old modified throttle body that I wasn't very pleased with. I also removed my TII throttle cable and went with the N/A throttle cable set-up.

Today I reinstalled the TMIC, reattached the battery cables, double checked everything and attempted to start the car. Here is what happened...

KEY to "ACC." = Prosport boost gauge lit up and did it's typical starting procedure.

KEY to "ON" = Cut all power.

KEY to "START" = Something made a ticking noise for a few seconds (maybe the trailing coils or main relay), idiot cluster appeared VERY dim, boost gauge turned VERY dim.

KEY returned to "ON" = Ticking noise from engine bay, tachometer bouncing, lights a bit less dim.



So far the main relay has checked out to be good, along with all fuses.

 

Check your battery cables and state of charge.

 

Is your top mount hitting the alternator?

 

The TMIC is touching the alternator, but not touching any wires. (big Taurus alternator.)

The battery was at ~12V earlier. I checked it before I even attempted to start it the first time. I put a charger with a "start" function on the battery and terminals. The lights on the idiot cluster were bright and there was no loss in power with key to "ON". When I turned the key to "START" the power dropped tremendously and there was only a clicking noise from the starter.

 

My earlier searches, fueled by an empty stomach, yielded very little information... My searches now lead me to believe that I may have a bad negative battery cable. I plan to clean ALL grounds and tighten all terminals on everything. Including the starter, alternator, and engine bay fuse box.

 

Does your battery have a cover over it to shield it from coming in contact w/the hood?

And the bouncing tach. Was it a single bounce or repeated bouncing that occured.

 

Yes. I keep the positive terminal covered at all times. I actually had been attempting to start the car with the hood up.

 

W/key to on do items such as wipers or blinkers work? The intermediate connector that is located a foot below the engine fuse box which supplies voltage to the ignition switch is tightly connected?

You can bypass the Main Relay by disconnecting the 4 wire relay plug and jumpering the B/G to the B/Y and the B/W to the W/L.

 

Repeated bouncing.

The wipers, headlights, hazards, etc. do not work with key to "ON". There is this odd tickng noise coming from the engine bay with the key to "ON". Particularly in the main relay and trailing coil area.

I'll have to check the intermediate switch tomorrow when I have more light.

 

The ground to the Main Relay could also be problematic, but bypassing the relay as suggested would tell you if that were possibly the problem.

 

Tried bypassing the main relay and sanded lots of terminals. Nothing. With the key to "Acc." I see around ~8V on two main relay wires and then ~4V with key to "ON" on the same two wires. :-/

I did notice that the positive battery cable terminal was pretty warm, though. I am going to try another battery I have around here.

 

This worked. ^ New battery... Fixed.

The odd thing was the proper voltage of the bad battery. That warm positive terminal was a pretty good indicator, I suppose.

 

Voltage does not a (charged) battery make.

When taking the key to start, a large load was placed on the battery. If there's little to no capacity, then the voltage will drop down significantly, causing relays to drop out from an under-voltage condition, giving you the silent treatment.

 

That's good to know for future reference.

I had never experienced that... Plus, I found a few mice in that little compartment that houses the windshield wiper linkage. (Between the firewall and dash/interior.) - It made me think that they may have gotten into the engine bay, or even worse... under the dash, and chewed up a bunch of wiring. Luckily they didn't. I cleaned their nest and **** out from that area. The mice really threw me off.


Appreciate the help, guys.