4k+ ignition break up.
 

Hey guys,

First off I searched but could not come up with anything conclusive.

Ive got a GSL-SE with 28X,XXX miles on it. It starts and seems to run fine. I am not new to rotaries but I am having a problem.

At about 4k and up the ignition seems to break up and makes the car buck hard. The car has a new fuel filter, wires, plugs, rotor and cap. The only other parts I can think of are the coils or ignitors. But I am getting spark on all four plugs.

Any suggestions or ideas.

Thanks,

Greg

Bump...

I need this thing ready for a rallysprint in May. I have some time but not that much.

Get you some MSD Blaster 2 coils, im sure those are the stock coils and that they are tired and worn.

These will be a good upgrade over the stock ones anyways.

-Matt

get an FC coil

About the coils. It was setup to run an FC coil on the leading. I changed to some stock coils to check to see if the FC coil was the problem. Same symptoms. I am a little stumped. I dont know if the coil I put in was bad also though. The timing according to the distributor position doesnt appear to have been messed with.

I dont believe the ignitors would cause it to act like this.

How long has it had the problem?

possibility that the new plugs and wires are also bad right out of the box?

Check the condition of the cap and rotor. Any chance this is a fuel issue rather than ignition? You might want to go ahead and verify the timing... Maybe run a can of Seafoam through the gas tank just for shits and giggles.. :)

Thanks for the suggestions. I will try some of these out tonight.

I was thinking it might be fuel as well. However it the fuel filter appears to be new and the previous owner claimed it to be as well. Still very shiny with no road grime. Same with the plugs, wires, cap and rotor.

I am not sure as to the condition of the fuel pump or fuel injectors. I figure those are about the only other fuel components that could be going bad.

The problem has been there since I bought the car in Feb. I just got the rust fixed last week so now I am trying to get it drivable.

rust in the tank

With the SE filter there is no way to see the inside of it.

I have a pinto with a rusty tank, Sometimes I cant even drive a mile it will get so clogged up.

I would change it, and beat that one on the ground a few times to see what comes out of it.

With that many miles on the car, that tank as seen alot of fill ups.

Would that cause a consistent break up above 4k though?

I understand the idea behind the fuel filter being clogged and if I was having strange power loss at random times or all the time it seems more plausible. I know its a cheap part to replace and easy too. However it seems that as soon as I rev to 4k it hesitates and drops down to about 3k and then will go back up. If I rev it up more it will rev but breaks up pretty badly.

Sounds pretty stupid, but look over the plug wires and make sure that they are routed correctly. Also, make sure that the leading ignitor is firing the leading ignition. Sometimes these things get messed up along the line. I found that my leading ignitor was firing my trailing ignition last year, which explained the spark knock I couldn't seem to get away from....

Put on the plugs, wires, cap and rotor from my other car. I also played with the timing a little by rotating the distributor. This did nothing to cure the problem.

I am running out of ideas pretty quickly.

any noises?

Not really. The engine shakes at these RPM when it misses and there is a rattle or clang that seems to be coming from the stock exhaust manifold.

I am probably getting my neighbors sick and tired of me revving the motor, changing or messing with something then revving it some more. Its got no muffler after the cats.

Off Topic BTW aws140...

Are you coming to the Mitty the first weekend in May at Road Atlanta?

Should be a pretty good time. I should be able to get you some free beer and possibly other goodies. We usually have a little party going on at our tent after the races. And a Flyin Miata Turbo kit is being installed on Tom's (co-worker) car during the races.

I was trying to get Billy to come as a vendor if not just a spectator. I want to stop by his shop while Im up there. Im also kinda bummed you got rid of those T2 seats, and to a guy who lives damn close to where I moved from.

Pull your fliter and if you have to cut it open to see what kind of crap is in it. I had a truck use to clog filters and the only time it would act up was on the interstate. I could stop sit ther and rev it all day with out a load no problem changed the filter problems was solved temporaly. The truck got so bad i had to change the filter once a month because it really needed a new tank. On another note because it is hard to trouble shoot on the internet check your internal timing to make sure your crank pulley is on right. It does not have a offset hole like the sencond gen. aws140 and myself had the same problem and you would be surpised how good these cars run 90 degrees out of time. post your findings and we will try to help you

I am planning on changing the filter just in case. It does act better just free revving than under load.

I'm a bit embarrassed to say this... especially after having an RX-7 for so long (8 years). I do not know how to check the the internal timing. Any good pictures or write ups?

Thanks,

Greg

im guessing its a timing issue. i just went through this exa same thing with my SA. just take the plate off of the back of the engine where you can see the flywheel.

set the front pully at TDC. then look at the flywheel. the "thicker" part should be pointed at the exhaust. i had a similar problem as you and mine was 180* off.

i dont know if ill be at the mitty or not. i should, road atlanta is 10 minutes from my apartment. ill look into it and possibly ask off for work. even if i cant, youre more than welcome to swing by the apartment and hangout.

yeah, those T2 seats were taking up room in myapartment for too long. i had to move them. IIRC, the guy who bought them might be selling them. hes trying to sell his SE now.

^^^ Keep in mind that the access plate mentioned is the one on the side of the motor, not the one on the top of the motor. I believe there is a complete writeup in the Archives on this...

aws140 and myself had a timing problem you will need to search the threads first. I just purschased a rb pulley and that is how I solved the problem someone can expllain this better than me. The only reason I would check the timing would be if you had the problem since you have owned the car. I would check your filter first or drive a the car with a fuel pressure gauge hooked up first and watch the fuel pressure. If you want to call me shoot me a pm because I suck at typing

as stated above, search the archieves theres a great write up by wacky in there.

if the problem just arised though, thats probably not what it is. i would look more towards fuel andignition components.

when you come to the mitty you can come byy the apartment and im sure we can find the solution.

sounds like a timing issue to me.
It also happens with the leading side of the ignition stops firing.

I've not had this problem with the SE, but my 85GSL had a similar problem that turned out to be a weak fuel pump: it was about 10% below nominal pressure and the car would bog at freeway speeds under added load, such as to pass.

Several people have mentioned scale and rust in the fuel tank, and that's a real possibility, especially for a used car that has lived in temperate climes where there is the possibility of repeated hot/cold cycles that result in condensation accumulating on the walls of the gas tank.

But if your engine bogs while unloaded, say sitting in the driveway, most likely it's ignition. Start with basics, like checking the distributor to make sure it's coordinated with the flywheel, as described above.

Thanks guys I will have to check out the timing. The car was purchased with this and the rust problem a couple months ago. I just fixed the rust and since the suspension is no longer tearing away from the body I am going to work on it's other issues.

There is a noticeable and audible miss when the car is in the driveway however it is violent under load.

I do know about the access panel and will search for the top dead center procedure.


aws140 - I would love to stop by, however I doubt I would be driving this up. If I take anything of my own it would probably be the blue car in my sig which will be going through break in at that point.... if the motor install and rebuild on that goes as planned.