Pettit Starter Booster For FC?
 

I'm looking into my weird starting issue and from what I've found, Pettit made a starter booster kit (which is basically just a relay) that seems to work well for the FD guys. Any idea if the same one will work on an 87 FC? I highly doubt it will, in which case, does anybody have a write up on how to rig one up myself? I did some searching but I keep coming up with this problem on FDs.

To clarify what I'm trying to remedy, it's what people on here are calling the "click-click-start"? Basically, at random times, cold start, warm start, doesn't matter, the car will randomly do nothing when I turn the key, just 1 click. Sometimes it takes a second time to start, sometimes it takes up to 4 times to start. When it finally turns the engine, it starts up right away. The reasoning for this from what I've read is accumulated voltage drops on the starter circuit - this looking for a solution.

Thanks!

Here you go, this should help you out:

https://www.rx7club.com/2nd-generati...video-1107943/

Yeah, that's one of the posts I had read but they refer to the Pettit part that states it' for the FD. Not sure if the FD shares the same setup my 87 FC does. That' why I wanted to check with you guys.

I moved the ground to the starter(harness ground on long bolt) and added another one.
I haven't had any problems with starting any of my last 11 cars..

You skipped the relay mod, and just added a ground? I will be redoing the battery wires very soon, and the relay mod was in order, but if adding/redoing the ground wire works...

I did not know of any Relay mod at the time I did this.
All I know is that the Solenoid gets 12v when you turn the key to start,which engages the starter.If the solenoid doesn't get that then the starter doesn't roll.
The starter itself needs to have a Pure path to get as much amperage(and full voltage) from the battery to efficiently roll the engine over,So any Relay mod being placed into it is either in the solenoid circuit or the Starter circuit and is just additional wiring in my opinion.
If you look at it you put the starter motor directly to the battery and it rolls over.
You hook the solenoid to 12 volts Switched and hit the key and it will roll over.
It's not a difficult system in that sense.The extra "clutch switch prevention" and so on are in there for safety But the starting system itself is just a matter of having good power to the starter,with good connections/contact.

Over the past couple years, I've too have had some weird intermittent electrical problems on my '90 GXL. Very slow moving windows, lights would sometimes dim when I hit the brakes, radio would cutoff when I hit the brakes, turn the key and nothing but try again and it starts, etc. The start problem was becoming particularly frustrating. Sometimes, it would take a couple/three tries before the would starter engage. Apparently, this start problem has affected many Mazda models such as the RX7 (FC & FD), RX8, Miata, MX6. Within the past year, I replaced my battery, starter and alternator. Not by process of elimination to solve this problem, but they had aged to the point of needing replacement. I then decided to change my battery cables too. The (+) battery connector was the original and was deformed to the point where I couldn't tighten it securely to the battery post. I didn't want unwrap the original harness, so I disconnected the original cables and ran new cables along side the existing harness. Mazda's half-assed idea of putting the battery cables in the harness. I bought zinc battery terminals with wingnuts on top (Duralast DL06070), bought 2 prefabbed 49" 4 AWG cables with lugs (Duralast DW449B), and fabbed-up 8 AWG positive and negative cables with lugs. The 12" 8 AWG positive cable ran from the (+) battery post to the 100 amp in fuse box next to the battery, and the 16" 8 AWG negative cable ran from the (-) battery post to one of the strut mounting bolts. I attached the 4 AWG ground cable to a starter bolt at the bell housing. I've eliminated (i.e., jumper-ed) the starter interlock switch at the clutch pedal, replaced the ignition switch harness (Rockauto Standard Motor Products US456), and replaced the security system's starter relay (Rockauto Airtex/Wells 1R1801) For now, this apparently has solved my electrical problems. Big improvement in my electrical system performance.

why keep the system a high amp loaded circuit though?

like the windows, all the current passes directly through the switch and causes premature failures eventually, sooner rather than later. the same is mostly true of the starter circuit, since it requires a decent amount of power to kick the starter solenoid over which also passes current to the starter motor. if the signal is weak, it just burns the contacts in the solenoid out quicker, in many cases the voltage and amperage low enough that it can get the solenoid to move, but not trip the contact to activate the starter.

the problem just compounds itself over time, affecting everything in the whole circuit including the starter if not addressed soon enough.

wow, that sounds like you did a whole new power system for the car. That's great! I just purchased the starter booster from insightful, from what I've read, that should solve my starter problem. I don't really have other electrical issues that I'm worried about. I had slight 3500 hesitation so I added in new grounds throughout not too long ago. Didn't help so much with hesitation issue - proper cleaned injectors fixed my hesitation issue:)

Thanks for the info and I'll update you guys once I get the part and install it.

This was done over a span of a year or so. Most recently, I replaced the battery cables because the sight of the original positive terminal always troubled me. It probably cost me under $50 for the battery terminals, cables and wires. I got the 8 AWG wire and lugs at West Marine, and even used their wire crimper. So, it's not an expensive fix.

Exactly what I have in mind, should be doing this somewhere in early 2018. I plan on making my own wires , in addition to what you did, I plan on running a (new) positive 8awg wire to the alternator post, and a negative 8awg wire to the alternator chassis.

I'm also considering running another 8 AWG wire from the alternator output terminal to the fuse block. I would leave the original alternator wires intact. FYI - I've found a company (Marine Wiring, Boat Cable and Electrical Genuinedealz.com) that will make custom battery cables with secondary wires for very reasonable prices. I might place an order with them.

Any quality car audio shop can custom make those wires for you, in fact, you can probably do it yourself, all you need is the wire, terminals, a hammer, and this:

i ended up buying one of these relays, still havent installed it. no one seemed to offer them up when we were talking about it last time got this on amazon or summit , dont remember which one, for $15

https://cimg9.ibsrv.net/gimg/www.rx7...50aafc5eda.jpg

I just remade mine with something similar (hella weatherproof relay) to get it water tight... since my old one failed:

https://lh3.googleusercontent.com/Ci...=w1024-h576-no