EvilWankel

iTrader: (2)

Well I just recently got a starter for my car, 85 GS with s4 13B. I had a FC starter in there, but it would grind a little bit when trying to turn it over so I got one from another 85, but it's a 12a starter. I've always read they are interchangeable, and I didn't think there is be much of a difference in the strength of each. When I took it off I noticed the wiring was a little different than the way mine is wired. So before I tried to fire it up I took my battery in to get charged because of how much I was cranking it before changing starters with no luck.



Well anyhow I installed it and tried to start my car, and it cranked SLOW. Sounded like I was trying to start some old school v8. I thought it was my battery and luckily it was under warranty, so I got it replaced but I got the same end result. Went ahead and tried to install a new negative terminal as well. This also did not help.

If you are wondering, work I've done since the last time it started was changing the intake manifold to s5 lower with racing beat adapter (previously rotaryshack 1 piece) for weber, and DLIDFIS. I thought that maybe my install of the DLIDFIS could have been incorrect so I switched back to standard ignition to get it to fire up.

As of right now I'm only trying to figure out why the starter seems to be turning over so damn slow. I'll include pictures of the terminals, battery, and connections at the starter as well as a video. If anyone has ideas or suggestions let me know. Thanks a lot.

http://www.youtube.com/watch?v=HvZRRuI2vqM

74RX4

iTrader: (10)

Not sure this would effect the problem, but the stock position of the ground cable is under the head of the front (long) starter bolt.

Siraniko

iTrader: (13)

It doesnt matter which way it goes so long that it is a good ground. To answer the real question, the FC starter uses the long bolt and a nut at the end. On the other hand, the long bolt is bolted to a pre-86 starter.

rx71king

iTrader: (6)

if you had a battery booster pack i would say use it...or charger the new battery for a hour..like to run a separate ground . engine to chassis.........

RotorMotorDriver

iTrader: (1)

Have you had the starter tested? Its possible its bad...

Also, is there a small ground strap going under the other solenoid terminal? The positive goes to the one, the other sometimes has a ground strap under it that goes to the solenoid case. Then of course you should have the smaller spade terminal which activates the solenoid.

Oh, and sometimes the wire corrosion INSIDE the wire can get too great and cause a large amperage drop through the starter wires. Replacing the old aluminum core wire with a higher quality copper wire and lugs can make a world of difference, not just to the starting system but to the overall electrical system.

~T.J.

EDIT: Just watched the video. Its not cranking THAT amazingly slow, but I do see what you mean. I've noticed that these things seem to crank slow for as small as they are. I would look at the cables myself. Mine spins pretty good, but I made all new battery cables for mine when I relocated my battery to the storage bin area. I also know that with 80s - 90s Toyota starters, there are different versions of windings (kilowatt ratings). Maybe its the same for the RX-7s?

EvilWankel

iTrader: (2)

I had a large ground wire strap from my engine bay that I tried to put under that second terminal on the solenoid. It's not supposed to have a ground from what I noticed (it wouldn't turn over, and after that the ground wire was HOT). I have been thinking about changine the wires as well, I'll look into that, thanks.

EvilWankel

iTrader: (2)

No, I didn't use the bolt + nut combo on the pre-86 starter. It is only the bolt, from the pre-86 starter threading into the starter

EvilWankel

iTrader: (2)

Ok well here's another update:

I put my other starter back in, and got to cranking again. It sounded like it almost wanted to fire up but wouldn't. Admittedly a desperation move, I went ahead and tightened down my motor mounts all the way (just put mazdaspeed mounts in), in hopes that some of the energy was lost in the engine rotating. That still didn't fix it so I started looking to see if I didn't cap vacuum lines, something I have checked before. There was no vacuum leaks but I noticed this plate on the back of the weber was a little moist (in picture 1, if it looks loose, it's because I loosened it to see if gas would leak out). After I saw this I took the top of the weber off to see about my float bowls and such, see if anything was glaringly obvious.

Now, I admit I dont know a lot about carburetors in general (any type), but I'm trying to learn. I'm pretty sure that the little area south of the bowls in picture 2 should NOT have gas in it. I think this happened when I took off the carb to switch intakes. I tried to not lose the gas everywhere, and I think it got into the wrong areas of the carb. The wife is taking a power nap, but after that I'm gonna go out there and take my carb off again and get that gas outta there. Hopefully that will fix it but it's just a guess.


Should I dig deeper into the carb or is this enough?

RotorMotorDriver

iTrader: (1)

I didnt mean to say ground strap, meant to say power wire. That's the power into the starter motor, sorry about that confusion.

What's happening is the power comes from the battery down the cable to the terminal on the solenoid. When the solenoid is engaged by power from the small wire, it moves the bendix into place, and allows current to flow through the solenoid to the other terminal, which in turn supplies the power to the windings in the motor to spin it, thus turning the engine. The ground is achieved through the bell housing bolts.

What I was getting at by asking was that sometimes that can be loose or dirty and cause an excess current draw and slow cranking.

~T.J.