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It seems like I've got an 81-85 distributor on my 79 Rx7, objectively good, but depending on how it was set up, could be bad. I attached some pics, so someone could confirm whether or not I do have an 81-85 dizzy. Or If I've got the rotor cap on weird. Anything looks odd, please point it out. If you've got ideas and need specific pictures, let me know, as well.
I got it to run pretty damn well yesterday fiddling with the timing. Even started again with two pumps of the pedal after killing it. Unfortunately, I had the coil wires swapped. Tried fiddling with the timing again this morning to get it to start and run again. No luck. Granted, I didn't try very long.
Is there some sort of way to set the timing by eyeballing the position of the distributor and the dashpot on the side since I haven't been able to get it to run well.
Also, would pulling switched 12v off of the leading coil for a wideband cause potential ignition issues?
that is an 84-85 distributor in the first pic you can see the N201 marking, so its an 81-82 manual transmission.
timing is probably right, if everything else is correct the distributor sits just off center. usually there is a 'witness mark' where the bolt was originally, and yours should be on it, or close
Any faint witness marks must be long gone by now, or indiscernible from the other markings in the area. I know the carb is where it should run. The lack of running is 90% in the timing for now.
I'll fiddle with it some more tomorrow and see what I can get out of it.
Normally a correctly stabbed and timed engine will have the bolt almost centered in the adjustment slot of the dizzy. Given you had trailing/leading reversed it is probably just off because of that.
The trailing coil is the most forward mounted coil and its high tension wire goes to trailing coil wire position on distributor cap.
If the engine static timing is correct and if when running seems to run ok,chances very good that static timing is correct and this does NOT change and should not be considered cause for no start,restart.
You should not be using the feed wire for either ignition coil for a power pickup for your air/fuel ratio gauge-or anything else. Anything you tap on to this circuit can lessen developed spark output at the plugs and while the FB electronic ignition puts out a stronger more reliable spark than a points system,it’s not that MUCH stronger.
So,disconnect that wire for your A/F gauge from coil feed and find another switched voltage source.
In your pic the distributor is not centered in the adjustment slot,most rotaries when ignition timing has been checke/set with a timing light the holdown bolt is pretty much centered in the slot. Where it is right now also will NOT cause a no start,just means the ignition timing may not be exact.
When car is running,does in dash tach read rpm?
Need to do some diagnostic process of elimination...next time it won’t start or restart-don’t keep cranking on it. Immediately pull all plugs,stick all plugs back into their respective plug wire and drape all plugs/wires on top of engine to ground them and crank or get someone to crank engine over while you look at the plugs. You should have same blue spark at all the plugs and they should fire in a regular sequence.
Any erratic/missed spark events should be investigated,try swapping one of the other plugs into that plug wire and see if erratic/no spark follows the plug or is same. If you have regular firing of a good blue color,pretty likely ignition system is not sorce of your no start. If the spark is weak and yellow/orange it could be a contributor to hard/no start and this could be caused by old/defective plug wires with excessive resistance and or worn out cap/rotor. Could be a weak ignition coil or ignitior,there are test specs for them.
If you have dissimilar spark quality between leading/trailing plugs,swap ignition coils with each other and test spark output again. No change,swap ignitors and retest. These are quick process of elimination tests if you have no test equipment.
If you have no spark at any of the plugs during crank test,check black/yellow power feed wires at each coil for proper voltage-they should be identical and with ignition switch in run position,should show 12-12.5 volts and should not drop appreciably below that when cranking engine with plugs installed. If you don’t have above voltage at coils-or no voltage there when spark testing, look at power feed from ignition switch. It is possible you have an intermittent connection from switch or a failing switch-not uncommon with the age of these cars.
Lastl,the battery/starter need to crank engine reliably and fast enough to start/restart engine. Rotaries need to be cranked over at a good rpm to consistently start.
A weak battery/dirty/corroded cables can supply insufficient current when cranking and a starter that pulls too much current from worn brushes or shorted commutator...both can sap enough battery power there’s not enough available voltage to power ignition system for a good spark.
If not sure about spark quality or cranking speed while trying to start,post a video of either or both.
The coils are correctly wired, at least to the distributor, then. The tach does read RPM. I'm certain cranking speed is fine, new starter, new battery cables, and a battery reading ~12.8 volts. Not sure of another switched 12v source as easily accessible.
Testing the spark revealed even, blue-purple spark across all plugs. The only video I did has one of them sparking between each other, so it's a bit harder to see. But I checked them a few times and they all are the same, even, purple-blue color.
Tried to watch your videos,no go. You can't get it started at this point? Have you done a compression test? Pull dist cap,rotor. Remove metal shield,put rotor back on. Turn engine by hand til rotor terminal lines up exactly with L1 terminal in dist cap. Look at timing pin in front cover,is leading timing mark on pulley right under it?
Both times I've done a compression test, it's read 85ish on both rotors. No weird bounces, though.
That's not great, I know, but it's a pretty fresh rebuild with maybe 150 miles on it, so I'm optimistic that the seals just haven't bedded with how often they've been washed out trying to get it to run.
Put that distributor back where it was and then a little more advanced and try starting again,sounds as if it might be a little retarded. If it sounds more like it wants to start at that point,advance it to end of slot and try again. If it starts and you can keep it running,put a timing light on it and check your marks. It might be possible it’s a tooth off,late.
Did you check static timing the way I suggested earlier?
What plugs are you running,are they gas fouled,what do they look like?
You say you have @ 150 miles on since rebuild,did it have good power?
Are the current problems you’re wrestling with new or been there since rebuild?
If, by static timing, you mean checking that the L1 rotor terminal is lined up with the cap terminal in relation to the timing marks, then no. Don't want to wake the parents by going out there.
By a tooth off, do you mean the teeth on the bottom of the distributor? Meaning the dizzy was installed slightly off?
On my last set of plugs: br7ets, I was getting an orange-yellow spark. Just a couple of days ago, I replaced them with some br8eq-14s. It's only run on the new plugs maybe 10 minutes. When I pulled the plugs earlier today to check for the blue spark, they were pretty well coated in fuel. This is because I've been cranking without it catching and running. They had some slight browning/blacking near the center of the plug, but that's about it.
The 4.5k I took it up to repeatedly when I drove it felt clean and powerful. Though, those runs were on what seems to be a stock(?) carb that also hated starting. I've got a thread about said carb here:https://www.rx7club.com/new-member-r...e-got-1127530/ If I still had everything for that carb, and the knowledge I have now, I'd probably have just rebuilt that one and moved on. Alas.
The previous owner before me is the one who rebuilt the engine. It had sat for a long time before he got to it. So, we've been dealing with these issues since rebuild.
Reason plugs you previously had in engine showed weak spark was because they're 2nd gen plugs and 2nd gen ignition system much more powerful than 1st gen. Basically your system doesn't have enough poop to fire those plugs properly. BR8EQ-14 plug is correct match for ignition system and why you now have correct blue spark.
So... the engine is flooded and plugs are gas fouled.In video i can hear fuel pump before you start car.What kind of pump is that,what kind of fuel pressure is it putting to carb?
I read your thread link about the carb but am confused as to what you have on the car now. If a NIKKI,both fuel bowls should be exactly 1/2 full looking at windows in primary and secondary bowls-may need a mirror to see rear bowl-are they? Has it been cleaned/rebuilt?
Does this carb have a choke plate? Take air cleaner off and without car running,open throttle fully. You should see a steady stream of fuel from accelerator pump discharge nozzles spraying into primary venturis. NEED to have this.
Do you know how to deflood engine? Take all plugs out and disable ignition by removing primary connector on each coil. Crank engine for 30 seconds or longer til all fuel mist is expelled,longer if necessary. Open throttle fully and pour a couple table spoons of premix or engine oil down primary venturis. If you have a small bottle that you can pour about a tablespoon of oil thru leading spark plug hole,do that. Turn engine by hand several revolutions(6) to spread oil around rotors/housings. This will help build compression by replacing film of oil on rotor housings that apex seals need to seal to housing that was washed away by all the extended cranking without starting. Don't know what method you have available to clean plugs,but at least spray the business end down with carb cleaner and blow dry them. Put them back in and try to start engine by pulling choke,give pedal 2 pumps to squirt fuel in to engine and crank it up. Couple things... the oil you have put in engine to help it start will put out quite a cloud when engine fires up. Advise your parents of this and maybe your neighbors. I have had a neighbor call the fire dept.as she was sure my garage was on fire...sometimes plugs that have been gas fouled,even though relatively new,will not start a rotary. May need to invest in new set.
If the car won't start with a reasonable amount of cranking,don't keep winding away on starter,you're just flooding engine. Pull plugs,if wet,deflood again,add oil if necessary. You can tell by cranking speed if engine is flooded,it turns over faster when rotor sealing is low as is compression.
Do all the ignition/timing checks 1st to be certain you're not wasting your time and reflooding engine. GL.
I'm currently running a brand new Weber 45 with jets that should run. I'm running a carter pump with a Holley return regulator that's reading about 3.1-3.5 psi.
I think I've heard that the f3 is basically the f11, but needs less vacuum to work, and is more ideal.
Edit: I'm not sure what you mean by the shield I need to remove under the rotor, or how to remove the rotor. Static timing seems perfect as it is unless I need to remove said shield to get a proper reading.
Carb jets specs look ok. The shield under the rotor that covers the pickup coils is missing. Aftermarket Pulleys,or did you paint those marks on there? Any provision for ported vacuum source on the Weber to connect to vacuum advance pods,would really add to partial throttle response/driveability and add fuel economy. Looking at where dist holdown bolt is located in slot,i would advance that timing a bit more to help get car running.
I painted the marks a few days ago, every 5 mm. I didn't have any yellow paint, so the leading mark is purple. There's no ported vacuum source on the Weber, unfortunately. I planned on having it run just off of manifold vacuum. That should be better than nothing.
I've got somewhere to be later, so I don't want to get too dirty working on it. Advancing the timing would be back where I had it, right?
Don’t worry about the shield,thought maybe you left it off.
Understood on timing marks.
If dist holdown bolt in center of slot,turn dist ccw a bit more and lock it down there.
I know this isn't the main topic, but you mentioned running the dizzy advance on manifold vacuum. That will do you little good as it will see full vac advance at idle from where it will then decrease as the throttle opens (not accounting for mechanical advance). Vac advance really needs a ported vacuum source (allowing it to see vacuum at part throttle and not idle), so if you connect it to the manifold you might actually get the opposite than desired effect. You will actually see less total advance (because now the dizzy is retarded to counter the vacuum advance at idle) and less timing in the part throttle region than no vac advance at all, assuming you've set the dizzy for the proper idle timing. With no vac advance hooked up, the vacuum pots on the dizzy should be left open, not plugged.
Just had to point that out. I'll read through the thread sometime here and see if I can offer some more assistance. Best of luck on your hard start issues.
There may be some option for tapping the carb casting slightly atmosphere side of the throttle plates. There's plenty of empty space there. Vacuum advance isn't my main issue for now.
Unfortunately, I hadn't gotten around to test starting it again after the timing adjustment. Will try to get that done early tomorrow and update again.
05-05-19, 03:24 PM
