Timing / Variable resistor Question
 

OK, I still can not find the info needed. I have spoke about this problem in other links where this was not the main reason for the link, so lets talk about this here.

I hope someone can tell me what's wrong.

OK, I have a rough idle problem and don't want to give up on this just yet.

Motor ides at 1100 rpms, variable resistor plugged in or not does not change anything.
OK, here is the setup.
1985 GSL-SE

S4 parts -- rotors, housings (small streetport), counter weight, uim, lim, tb (with mod done), and dynamic chamber.

GSL-SE parts -- front cover, e-shaft, oil pan, AFM, stock tranny, and gsl-se injectors rebuilt to 704 and 705

Other parts - Full RB streetport ehaust, no emissions except sticker under the hood, Cone filter, RB lightweight flywheel, OMP still intact, 160 degree thermostat, and that is all I think.

I have tried to set the timing several times and the only time I can get it to idle smooth is when it has no power (retarted timing).
I even tried plugging in a Variable resistor from another gsl-se and it did the same thing as mine which was nothing!
Anyone have any ideas??? I would like to get it dialed in so I can take it to deals gap (4 hour drive).

704 and 705 fuel injectors. All four? Seems like a lot to me. What ECU?

the more accessories missing off the engine the more i believe this is a problem with the lightened flywheels.

the more drag on a rotary engine the smoother they tend to idle.

Air fuel ratio plays a big role.... my large street port purrs like a kitten at 5-600 rpm at times (BACV gone now that megasquirt is in) and it gets real rough if it is too lean or rich. Retarded timing generally idles smoother but kills the power, and the variable resistor should change your idling air fuel ratio enough to hear a change in engine smoothness at idle. As a last resort you can angle the air flow meter to change the effect of gravity on the flapper valve. Also have you checked your TPS? Don't want to be in closed loop (rich mode) at idle.

Sorry, this motor is in a gsl-se so I am only running two injectors.

With what ECU?

So if it don't do anything what could cause it not to work?


Yes and it is set fine, or it was 2000 miles ago. I will check it again.


At an idle I think I am very rich as the fumes gives ma a headache quick. Also being around the car will smell up my clothes in no time.

So if it don't do anything what could cause it not to work?


Yes and it is set fine, or it was 2000 miles ago. I will check it again.


At an idle I think I am very rich as the fumes gives ma a headache quick. Also being around the car will smell up my clothes in no time.

So if it don't do anything what could cause it not to work?


Yes and it is set fine, or it was 2000 miles ago. I will check it again.


At an idle I think I am very rich as the fumes gives ma a headache quick. Also being around the car will smell up my clothes in no time.

So if it don't do anything what could cause it not to work?


Yes and it is set fine, or it was 2000 miles ago. I will check it again.


At an idle I think I am very rich as the fumes gives ma a headache quick. Also being around the car will smell up my clothes in no time.

Wouldn't this be more appropriate in the 1st gen section?


-Ted

Well no since not to many 1st gens are running FI

Doesn't the timing advance itself at the rpm?

That's something you might consider. Around 1000/1100 rpm the ECU on a series four advances by itself. So if you are looking at the timing with a light it seems the marks should not align. The rpm's need to be under 1000 when timing for sure.

I'll admit some ignorance here. I"m not sure what would happen if you tried to time it with the rpms high and installed a initial set coupler while trying to time it. I've never done that myself since my idle has always been in the seven hundred eight hundred range when timing.

Then again I don't know if the fuel injected first gen had a cas or a dizzy. If a dizzy then forget what I just wrote.

I don't think the variable resistor is going to show any effect with the rpms over 1000. If in doubt just turn it to L all the way and leave it there.

You have to get the rpms down. The throttle plates must be cracked open too much or maybe if you have a bac it is stuck slightly open. I wouldn't try timing until I go the idle DOWN. Forget the variable resistor as being the problem.

Thanks, this does make alot of sence. I am running the gsl-se dist.
I will look into it.

Well if its a distribuutor, the timing hasn't much to do with the ECU. I THINK the distrbutor uses internal weights/vacuum to advanve the timing. I'm totally ignorant there.

Yes, to my understanding the dist does change the timing on its own internal.
I am gonna have a friend come over to look over my motor also. We need to first figure out why we can't get it to idle below 1k. If we can get that idle down maybe everything else will fall into place.

I don't get it. You're running only two 700cc injectors on a series 4 ecu?

No read the first post,
it is a 1985 GSL-SE.

It has a s4 motor, using 2 gsl-se injectors, gsl-se ECU, gsl-se oil pan, and gsl-se front cover. I posted it in the 2nd gen section for help since it is a FI S4 motor and because I have spoke about this problem in the 1st gen section before and still have not found the problem.

This problem is not for the average rotor head. Several of us have looked this car over and tried several thing but none of us have been able to solve it.
The person that can solve this will be named Master OF Rotaries!

standalone! :p:


as i said, i tried tuning it out on a friends engine with a light flywheel and was unsuccessful, small variances in compression and injector calibrations can cause the rotors to run at varying speeds(fighting each other, pulsating the idle) at low RPMs. much like a motorcycle with carbs that are out of sync, the first thing i would have done is send out the injectors to have them flow tested, cleaned and calibrated. check the compression numbers, anything varying over 10% from rotor to rotor will probably add to the problem as well. exhaust runner length, everything plays a role in power balancing and at idle with no load on the motor is when the balance is most noticable, with accessories removed and the light flywheel you have cut almost half of the idle load off the engine so it will be harder to get smooth and keep it smooth.

this is just my assumptions though, it could be something completely aside from this.

but really, first you need to get the idle down so that at least the variable resistor and the timing can be set properly. if the variable resistor isn't doing anything then the idle is either too high or there is a problem with the MAF air bleed screw or internals.

Yes, and thanks for the help.
The injectors were done and flowed 704 and 705. RC engineering built them. The stock gsl-se injectors are 680 so these are a bit larger. They and the motor have 2k miles since the rebuild.

As for the motor I am still running AC and power steering but no emissions what so ever.

I think I am gonna try to figure out why I can't idle below 1k first. Maybe then once the idle comes down I can get all the other problems fixed.

I know the lightweight flywheel will cause my idle to be somewhat off but nothing like it is now.
I might try running it with out the vac advance on the dist. just to see how that is.
Main thing is to figure out the freaking idle!

Ok, normally people I see doing this tend to use the 2nd gen ECU. I'm sure you've double checked everything, and had no luck finding vac leaks? Usually if it won't idle under 1k rpm I've ALWAYS found it to be a vacuum leak problem.

try pinching off vacuum lines one at a time, spray some water (spray bottle) or carb cleaner around the intake manifold to see if the RPMs get rougher or smooth out indicating a vacuum leak.

Ya, well I was restoring my gsl-se when the motor threw a rear apex seal at 120mph so for the most part the rear housing and rotor were toast! So while looking for good parts to use a fellow rotor head said why don't you use the s4 rotors and housings? So I did, then we said why not use the s4 intakes so I did again.
Basically I want to keep it mostly gsl-se and I do have my stock intakes to swap back to if I ever decide to sell her but I don't think that will happen due to the money i have in her.

I will spend this weekend trying to figure out whythe idle will not come down.
I think once that is done all the other problems will fall into place.

Pull the intake duct off the throttle body, with the engine hot, and see if the throttle plates are CLOSED like they should be.

If it's series four throttle body it will have a thermowax device with fast idle cam etc. It's meant to keep the idle around 1100 when the engine is cold and as the engine warms up the cam moves and the idle drops down to an acceptable 750 rpm give or take..

If the engine is cold and you look at the primary throttle plate it will NOT be fully closed. It will be cracked open a touch due to the thermo wax device. You need to have water flowing thru the thermowax in order for the thermowax to expand and cause the roll pin to fall off the cam which causes the throttle plates to fully close.

See the free online fsm for the series four. The FUEL section. It shows the fast idle cam/fast idle screw/thermowax etc.

I'm betting that the throttle body does not have water going thru the thermowax which in turn means the throttle plates are staying cracked open a touch keeping the idle high.