smile444

My 1985 RX-7 GS is experiencing problems with running anywhere close to smooth. I have gone through many important steps to get this car to run well, and have ran into a rather unique problem.

Here is what I have done so far:

1) Complete rebuild of the carb,

2) All-New Exhaust (Armor-coated Monza Pacesetter Header, then straight pipe back to the muffler),

3) Removal of the Catalytic Converters,

4) Complete removal of the Rat's Nest using RX-7 Carl's tutorial,

5) New Bosch Platinum spark plugs,

6) New Fuel Filter,

7) New OEM Fuel Pump.

After all of this, the car still runs like ***, and only gets about 10mpg.

I bought a timing light and found this rather unigue problem when trying to give my REX a tune-up:

-*-* THE YELLOW AND RED MARKS ARE TUNED TO THE REAR SPARK PLUGS!! -*-*

These are the ones that are marked on the dizzy as L2 and T2. It makes absolutely no sense to me as far as anything and everything that I have read in the Mazda Workshop Manual, the Haynes Manual, or on old threads here.

The car is somehow timed completely bass- f*cking- ackwards. No small wonder that it runs like ****.

I have attempted to somehow fix this, and have pulled the dizzy and aligned it with the markings on it, but it makes no difference.

I also called multiple service departments at MAZDA dealerships and they all concurred that the timing should only be set on these cars from the front plugs (Ie. the L1 and T1).

HELP!!

I even believed it to be an ignitor problem on the trailing, but all plugs are firing fine.

I need some sage advice here, this is my daily driver, and I am very very confused about this weird situation. I guess on the good side is that I have eliminated nearly all other possible problems.

Experts and Gurus please weigh in here as soon as possible.

Thank You,

Joe in KC

bliffle

I don't know about the RX-7, since I've never had this apart, but on some piston cars the distributor keys into the drive in such a way that it is possible to key it 180 degrees wrong. Seems to me I had this problem on an old Fiat (what else!) and so I had to switch the plug wires to make it run right. Seems to me I made a mental note to switch the dist some day.

B

Wankelguy

Perhaps the front pulley was disassembled and then reassembled wrong.

smile444

okay, so bliffle, would I just switch the L1 plug wire for the L2, and the T1 for the T2?

smile444

Wankelguy,

Are you thinking that the pulley is somehow attached 180 degrees in the wrong direction? Or could it be?

REVHED

The only possible explanation is that your front pulley is installed 180* off.

This is not the cause of your driveability problems though! If the timing is correct for one rotor it will be correct for the other one as well due to the way the dizzy works.

REVHED

I just realised something... if the pulley is installed 180* off and you proceed to install the dizzy according to the tally marks on the shaft then the timing would be way off. Each rotor would be firing when the other's supposed to. Your car would run like extreme crap if at all.

It makes your head hurt when you start thinking about timing on these things.

smile444

REVHED,

So, um, . . if I switch the T1 & T2, and switch the L1 for the L2, then I would have it at least adjusted correctly?

Wankelguy

Yes, and yes. The pulley is a two-piece affair, and if it is reassembled wrong, the timing could be way off. If my memory serves me, (and it frequently doesn't), the front rotor is at TDC when the key in the E-shaft is at the 9 o'clock position when viewed from the front. I'd get a second opinion on that, though. Good luck. -WG

smile444

WANKELGUY,

Would you agree that my rotors are firing when the other one is supposed to? If so, would a temporary fix be to switch the plug wires?

Wankelguy

I would hesitate to say yes, without being able to check it out myself. I'd take the fan off and observe the position of the key in the pulley relative to the timing marks to determine if the pulley is in fact wrong. Maybe just the coil wires or trigger wires are switched, it's hard to tell without going through the whole system methodically to eliminate the possible causes. Sorry I can't give you a firm answer, but I don't want to give erroneous advice, however well-meaning. -WG

1985 gs

I had the same problem on my 85 gs. I couldn't figure out why it still ran like crap. I checked everything ten times over. Timing was all screwed up because i kept adjusting it and had the plug wires mixed up. Just my thought.

smile444

WANKELGUY,

I believe that I will take the fan off and observe the position of the key in the pulley.

By the way, what does the key in the pulley look like?

smile444

Hey 1985 gs:

Did you ever start to get the timing set right once the plug wires were arranged correctly?

Wankelguy

The keyway is a slot in one side of the hole in the middle of the pulley. There is a steel key in it to index the pulley's position. You'll know it when you see it.
Good luck!

smile444

After pool league tonight, I will see if I can take a peek. I'll let you know.

Man I can't wait to get all this stuff set right.

bliffle

I would check it out carefully before switching the plug wires (heck, I just did it on an old Fiat), for fear of blowing apex seals.

But, I think if you examine it carefully and analyze the way the dist works, you'll be able to figure it out.

This is why I'm glad I have two cars: I can look at the one that's working and compare with the faulty one.

B

smile444

Good call. I already did switch them once, and I don't trhink it did any damage to the apex seals. But hey, how would I know??

I'll study the dizzy.

I need a second car.

REVHED

Does the car actually run at the moment?

smile444

yes

74RX4

iTrader: (10)

https://www.rx7club.com/forum/showth...&highlight=TDC

This thread describes how to find TDC. The keyway is at 9:00 when the engine is at TDC.