Shades

Hi

Been fascinated by the Wankel and the RX-7 for some years now, after a LONG wait (6 years or so) i finally get one.

The car as been a blast to drive, but since this morning have been having a problem.

The car is running on the front rotor, it was fine this morning when i went to get some stuff, when i get home i shut it off, a couple of hours later i return and when i start it it runs on the front rotor only.

Starts and runs on just the L1
Almost runs on just the T1
Does try to start on just the L2 but doesn´t make it
Just cranks and cranks on T2 but doesn't sputter or anything.

Had the plugs out one by one and it does have 3 even "wosshes" on both the front and the rear rotor ( it's the only test on compression i have for now), i don't think i've lost an apex or even a side seal, the "whosses" are very even and alike.

Looking thru the carb it squirts gas on both chambers as it should and i can't see any difference in the amount of gas it gives to the front or the rear rotor.

I'm getting lost trying to figure out what it is.

For what is worth the car doesn't have the hose from the airpump to ACV but it has been running fine like that (just a bit noisier and backfires a bit more too), no disconnected nipples anywhere on the carb. It's the only "modification" it has. My rats nest consists of only one solenoid and it's like that from factory in UK cars, its the blue one. everything is still connected to it

I live in the UK and the car is a UK model, buth many things i suppose are the same.

I did a few searches but didn't come up with anything more to test than what i already have done.

So, to sumarize, i have compression on both rotors, have spark on both, have fuel on both, but below 2500 it runs on the front rotor only, and after that it runs on both, since i don't feel any loss in power and the cars revs nicely in neutral all the way to 8000 after 2500 3000rpm somewhere in between that.

Sorry for the long post and sorry for speling errors, althought i'm in england i'm portuguese, and only arrived here a few months ago, looking for a better life.

Thanks for any help that you can give

JIMMY54

iTrader: (2)

I'm portuguese too....

Well if you have fuel and spark on both rotors then they are working. did you check for spark?

check the distributor to see if it came loose.... inspect the distributor car and the rotor inside for any corrosion or wear.

Check for vacuum leaks, because one leaking vacuum line and mess up your ilde and low rpm operation of the motor. Little cracks on those old hoses.

Good luck and keep us posted.

Shades

Hi,

thanks for the tips.

Did check for spark with each individual plug connected to the leads and the body of the plug against the shock tower and they all fire OK, the cars does accelerate smoth with no stumbles or anything like that but at idle it clearly is running on one rotor the engine shakes alot and occasionaly stalls.

Gona check for vaccum leaks will post in a second with my findings

Cheers

Shades

OK, update

no vaccum leaks, when i spray carb cleaner thru the air filter it does rev up, but i sprayed the entire engine, all the hoses, even the air pump and ACV and nothing, does not rev up.

kgray

What does the car idle at? It sounds like the leading plugs are fouling at low RPM's and clean up around 2500. How old are the plugs? Try sandblasting if you have the resources and blasting them with brake cleaner, if not replacing them. What year is it?

Shades

The plugs are a couple of months old, but i've cleaned them till shiny.

I just put a hose from the airpump to ACV so now the car is like it came from factory.

One thing i've just noticed is when i turn on the ignition, only the parking brake light comes on, but they all should turn on untill i get the engine started and then all go out, thats how it should work, all the fuses are good, but hear this, my car now runs with ALL of them removed, even the "ENGINE" fuse, i remember when wiring my remote central locking that without this fuse the car would not start (i forgot to put it in when i finished the wiring) the only thing that runs thou is the engine, i have no dash lights, no fuel pump, not even my tach with the fuses removed, but the engine runs.

I keep changing direction on what to fix, gonna check this electrical problem first, since i only just discovered it.

Oh yeah the car is an 83 but built in october 82

the car used to idle at 750, but now something must be keeping the idle up so it doesn't stall, it steadys at about 1000

kgray

the idle should be where it used to be. What happens when you try turning the idle down? The high idle signifies that there is still a small vaccuum leak somewhere, which can be very hard to find..

two79rx7's

the engine runs without fuses

Just by memory two fusable links (F.L.) in the engine bay protect the ignition circuit. You will get ignition without fuses.

the third center F.L. is in series and before the fuse box

the fact that L2 does not support engine firing like L1 is probably where your problem is. try swaping ignition wires between L and T and coils - check resiistance for each part, do ignitor tests ( make sure there is a generous amount of heat sink compund used for each ignitor ), clean up connections, look for broken - burned wires. is the trailing advance messed up and stuck due to faulty vacuum actuator or gummed up linkage giving you different timing for L and T?

Shades

Hi

Problem solved, it was somekind of bad connection on the fuse box, after cleaning the contacts and putting new fuses in, now idles perfect at 750 as it should, runs on both rotors, and is a great car again lol.

When i said "something must be keeping the idle up", what i meant was, because it was running on one rotor, maybe some solenoid or something was ON to keep the car from stalling, vaccum leaks i had checked and there was none.

Thanks for all the help, i really apreciated it.

Let the modding begin.
Already have a turbo kit from an elford, but i'm only going to pick it up in august, till there, new shocks, springs, the brakes already have been checked, steering box still haven't taken it apart fix but will be on priority, already bought a new ignitor to do the DILDFIS ignition (if you want new J109, well the equivalent, for 25Ł go to http://www.vehicle-electrics-online.com/ they only have 4 left) then some rust issues have to be solved and paint.

Once again thanks for the help. Keep the 7 alive
Cheers
Hope to have a nice car by the end of the year

Shades

Sorry two79rx7's, i was posting while you replied, everything is OK now, the timing is spot on at least is equal to the FSM, don't know if there is a better setting for them tho, any advice on what timing should be, stock everything on the car.

kgray

Glad you got it worked out. Enjoy the car!

two79rx7's

read some threads on giving additional advance to timing
there was a great thread about two months ago on this \
the guy was getting over 30 miles per US gal.
remember the rotary has great volumetric efficency compared to pistons but there is so much surface area buring combustion that there is much left unburned compared to piston engines.....So mazda made factory settings so that there was enough left unburned to feed the "incinerator" in the exhaust to clean things up there....IE too rich and not enough advance!!!!!!

I think there is room to lean out the carb, add advance and put on at least a header and run a better ignition for spark. but monitor exhaust temp.

search around in the archives here and come up with a plan. then post it here for others to comment on and add advice.