1983 RX7 S2 - Flo

[Lucky]

Hard to tell from static pics. Mystery hose might be the fuel return line?

[ian65]

Your ignition coils should be wired up like this....





the coil with the blue lead caps is the trailing ignition, the one with the black caps is the leading ignition..... the leading is the most important one... the car will cough, splutter, misfire and generally be sick if the leading ignition is down, if the leading is ok and the trailing is down, the car will still run and be driveable but will run with high emissions..... obviously, you ideally want both systems working 100%.

The leading coil should have a black wire with a white stripe and a black cap going to its positive terminal and a yellow wire with a green stripe going to its negative terminal.
The trailing coil should have a black wire with a white stripe and a blue cap going to its positive terminal and a yellow wire with a light blue stripe going to its negative terminal.

Here's a link to the instructions showing how the ICU connects into the ignition....... the best thing to do is to disconnect it and restore the factory wiring as above.

viewtopic.php?f=21&t=1549&p=15251#p15251

[Tepper]

Thank you so much!

[Tepper]

A bit of progress to report on this - I've rebuilt the carb with a rebuild kit and put everything back to spec, including float levels which were way off. We were prompted to look at the float levels due to severe flooding, which was eventually put down to a mostly blocked fuel return line - with the return run into a bottle the levels in the sight glasses are OK. Also, all potential sources of vacuum leaks have pretty much been addressed. The rat's nest was halfheartedly removed when I bought the car, so as a troubleshooting measure everything apart from the leading ignition vacuum advance has been blocked off on the rubber block between the carb and the manifold. It will start by itself and just about idle now, but usually dies pretty soon after. When revved it coughs and splutters, then dies when the throttle is released. The mixture and throttle screws on the carb are set as per the defaults in the Mazda service manual. My suspicions are starting to turn towards the ignition side of things, but fortunately I have a big box of goodies from Rock Auto including a rotor arm, dizzy cap, leads and spark plugs, amongst other things. These will be going on in the near future. The old Micro Dynamics ignition control unit has been disconnected, too. Could the leading ignition be causing these problems as I have been kindly advised before? Would swapping the coils round be a worthwhile troubleshooting step? I'll get some pictures and do a proper update when I get the ignition parts fitted. Any advice, as always, would be much appreciated. Oh and finally, I got the car up in the air today: fortunately it all looks really solid, including the rear of the sills and the mounting points for the rear axle etc. Makes me think Flo should be worth the effort in the end!

[ian65]

as a starting point, swap the coils over and make sure they are wired as shown in my other post.

[Tepper]

Thanks Ian, I swapped them over and checked that they are wired correctly. Any news on those coils and the clutch? One of the coils is not the original item and when swapped around the car became even harder to start, so I reckon at least one of the coils is no good. I took the opportunity to install the new rotor arm, dizzy cap and leads. The dizzy looked like this inside, all OK there?



After fitting all this, the car started perfectly and I thought I'd finally gotten to the bottom of this, but it died soon after and returned to not wanting to start. Really not sure what's going on there! While in the area of the coils I had a look at this:



The black wire coming from the +ve side of the battery is run into the screw terminal, which is then connected via what looks to be a staple to the rest of the wires.





I think these should all be a permanent live, I'm just confused as to why the staple hasn't melted - surely it can't handle that amount of current?

[ian65]

I'll sort the coils and clutch out for you this weekend, sorry about the delay, had a few problems the past month which is why I haven't really been on here. That connector block looks a right bodge..... can you post a photo of the 10mm bolt that holds the dizzy into the engine?..... that might give us some idea about your timing

[Tepper]

No hurry, this car's coming along at a fairly relaxed pace to say the least... I'll grab a pic of the ignition timing next time I'm up at the garage.

[Tepper]

Spent some time messing about with the car today with the assistance of a mate, last time I looked at it the carb was pissing fuel out of the primaries, so I adjusted the float levels again and put some vaseline on the new viton float valves (supposed to help them seal). The float levels are now exactly where they should be and it doesn't pour out fuel anymore, so I think that's sorted. I also fitted the replacement coils kindly supplied by Ian. Having sorted out the carb, it fired up nicely but died shortly after, same as before. After adjusting the idle screw, we got it starting and idling on the choke, but it dies when you start to take the choke off and that's as far as we got today. I'm thinking ignition timing is perhaps not where it should be, this is a picture of the adjustment on the dizzy:



We also managed to change the mashed driver's door lock for a new one and made a start on removing the towbar. My thoughts on the running issue are possibly a vacuum leak still, the inlet manifold is showing evidence of a water leak so could it maybe be leaking air as well? I've got a new gasket and O rings to go on so maybe that'll sort it. As usual any pointers are much appreciated. Hope everyone's had a nice Christmas too

[TOOL]

Dizzy looks fine on the inside.

Re timing, that photo doesn't mean anything without knowing you've set the base timing correctly i.e. has it been out and it slipped a tooth when it went back in?
You need to check that the dizzy is in the right place when at TDC. I do it like this:

Set the engine at TDC off the pulley marks
Look at the dizzy cap and find L1
Remove the dizzy cap and look at the rotor arm
Is the lower post on the rotor arm (one of the 2 leading plug posts, the one with the arrow on it) pointing where L1 should be?
If yes, then it's in the right place.
If no, pull the dizzy out and put it back in till you answer yes.

From there you can adjust the timing, but you should be somewhere near the middle of the adjustment. You'll ned a timing light.
Do it with the vac advance tubes removed and plugged.