here's the latest condition, I'd say a huge improvement, but still not perfect.. any ideas?

 

Guys, this is a great thread. I had just yesterday posted my idle problem on the 3rd gen pages before I found this one. See below...

https://www.rx7club.com/forum/showth...t=idle+hunting

I have had this problem since my rotor was rebuilt and the trottle body removed and cleaned.

As the throttle body uses many of the same bits and pieces I'll be trying to work through some of your ideas. I don't want to hijack this tread at all but there is some stuff I have read that I don't quite follow. So it would be great if you guys could keep an eye on my 3rd gen problem above. I'll try to get back to the post with more info and pictures as I diag the problem.

Help in Australia for these cars is practically non existent!

Cheers,
Andrew.

 

Yes. You should try adjusting the fast idle screw and also if that other screw that sits on top of the Water thermowax plunger is still turned all the way in, adjust it out some.

The FSM Fuel section shows the adjustment. You know, the temperature marks on the cam etc and aligning them. This being a fairly old car you may have to fudge the adjustment some as far as the temperature marks go.

You should be able to put your finger on the trottle cable and push sideways on it a touch without the throttle responding. Not dead tight but not loose either.

I should have mentioned making a note of where the variable resistor screw was prior to moving it. It's not a big deal if you didn't though. IF the idle was better after moving it, then good. Usually towards Rich makes it smoother. Lean makes for a poooh, poooh, poooh sounding idle.

The throttle stop scew looks more NORMAL than in your first pictures.

I just looked again at the first picture in one of your last posts, and yes, you need to back off that screw that is sitting on top of the thermowax plunger a few rounds. IF the idle picks up, then adjust that *other* screw, the fast idle screw.

Your on the right track now.

By the way, what could be wrong is the water passages b/t the thermowax and the throttle body my have a lot of crud/corrosion/ stuff keeping the passage from fully heating the thermowax. That would require removal of the throttle body and some downtime to clean out. How long? Depends if the phillips screws all come out good and if you can find a gasket for the thermowax (could make one out of gasket paper or use RTV carefully/judiciously).

 

For possible vacuum leaks I just fully warm the motor up and spray starter fluid around the possible leaking places. Like the hoses, ACV, hose at the BAC, back around the back of the throttle body where the three/four vacuum hose are, TID joints etc. Starter fluid only last for a short time but to me is well worth it.

When you engine was idling at 1500, it just was not a practical thing to spray for vacuum leaks. The change in rpm would have been marginal if you hit a vacuum leak. Now that the idle is reasonable, it is possible to check for small leaks. Although it does seem the throttle plates being too far open was the real culprit. The engine sounded toooo good when reving up/down/up/down for it to have been a serious vacuum leak.

EDIT: The screw in this picture is the one I think needs some backing off on, and then adjust the fast idle screw to correct any dropping off of the rpms when you do that: http://i23.photobucket.com/albums/b3...d/101_3141.jpg

 

By the way, what kind of digital camera is that? Model number/name please. Approx cost?

 

And we both need to thank SCRIP7 who tried to correct some of the blundering things I said. He seems to be THE MAN to go to have your RX worked on.

 

I already backed that screw off as I was adjusting the BAC and the tps, but i can probably back it off more if I adjust the "other screw" which I haven't touched yet.

I had the throttle body before a number of times, I'm actually pretty good at ait by now, so I'll take it off and clean out what I can from coolant passages to the thermowax sooner than later.... like i said though i'll be checking for leaks and just general repair/ maintenance stuff as well...


Its a Kodak Easy Share Z730, it takes both pictures and movies like the ones in this thread, it was like $250 at Staples two years ago, probably find em for pretty cheap but the kodak is good, i dropped it down mountain sides(150ft of rolling bouncing and smashing and onto concrete floors and it's fine, still working after two years of abuse...

 

Does it come with the Zoom Lens? Like this one I see online? ****SCHNEIDER-KREUZNACH C-VARIOGON 3X Optical Zoom Lens**********

The close ups of the screws etc were pretty clear compared to some other pictures I see on this site. I suppose they're using phone cameras etc.

 

No need to thank me. Glad to help. And you did just fine Hailers, I agree on the coolant passage clogging also. The water port on the rear iron is prone to clogging, as well as the hose nipples on both the thermowax and BAC. Before removing the throttle body, let's try something first. Disconnect the coolant hose after the BAC where it connects to the water pump return. If you can collect coolant in a small bucket, it will leave you with less mess. Start the engine and look for decent coolant flow. Not a trickle, but not as fast as the kitchen sink flow either. If no or low flow, backtrack to see where the restriction is. Check flow before the BAC, and even at the thermowax if you have to go back that far. See where I'm going with this? No heat to t-wax, no extending of the plunger and fast idle too long. Kapish? haha. Sorry I wasn't available today, took the kids to an airshow at Tinker AFB.

 

If you happen to like my pics of screw locations, I use a Canon PowerShot sd600. I absolutely love this camera. It's easy to use, feature-laden, 6 megapixel with video and zoom, it interfaces seamlessly with my pc and my tv, and it was $270 at WalMart.

 

I am not yet very familiar with s6 idle control devices or ecu inputs/ outputs. I think it uses an idle stepper motor instead of a pulsewidth-modulated BAC like the s4 and s5, not positive on that. There may be a downloadable FSM if someone here has a link to one.

 

Greenbudd, I watched your latest video, sounds muy bueno. Have you tried a little propane at this idle speed?...Add just a little bit. If it gets rougher and drops a bit in speed, the mixture is pretty damn close. If you can get a hose on the torch, say 3 ft. or so, run the hose down in between the upper intake and the "keg" (engine housings, near the primary injectors). Look for changes there and also between LIM and keg, at the gasket flange.

 

mine has the same lens but w/ 4x optical zoom.............don't worry about digital zoom, I personally don't even bother with the digital zoom, actually I have my camera set so that it only uses the optical zoom now for better quality pictures.

It stores all of the movies and pics right onto an half gig SD memory card that fits right in my pc for ultimate ease of file transfer, just drag and drop.

 

I'll keep looking for more air leaks, I really want to take my turbo inlet duct off and check it for cracks as well. I'm gonna check my timing finally as well now that it's below 1000rpms.....now it's just time to continue the upkeep.....

 

That's a pretty good idle, I have it like that on my sport and T2.

 

OK, couple of quick questions...

When at normal operating temp I take it that the fast idle cam should have separated from the roller?

In my case it does not. Then is it correct to simply adjust the fast idle screw which normally rests against the thermowax rod. Or, should I be adjusting the screw attached to the roller which is practically impossible to get at. From the manual it is not clear what each screw is used for specifically.

The second query I have is in relation to the dashpot. From what I know this is used during deceleration to prevent the throttle plates from closing too quickly. How should it be setup? I figured that the dashpot should be hard up against the stop it hits against, fully compressing the piston in it at all times, only extending and separating from it at around 2800 rpm. Is that correct? If so I cannot adjust my dashpot forward enough to make this happen. It is all the way forward now and only just touches the stop with minimal compression of the piston. Not sure why this is the case.

Any help appreciated.

 

My understanding is that the 77'F matching mark on the fast idle cam should line up with the center of the roller when the engine is just started, once fully warmed up the fast idle cam should fully seperate from the roller.

If the mark is off at 77'F then you turn the "cam adjusting screw"(the screw labeled SCREW here), this si the screw that sits on the rod of the thermowax unit:

to align the marks, or turn it all the way to the right to force the cam to release(what i did earlier in this thread)

So the above mentioned screw is what you would use to align the marks with the center of the roller or to temporaily force the cam to relase for diagnostic purposes.

The other screw is the actual "fast idle adjusting screw" which is used to adjust the clearance between the primary throttle valve and the throttle bore, which effectively sets your fast idle.


If your cam isn't releasing from the roller check to see if the thermowax is extending all the way or at all, then maybe try to turn the cam adjusting screww all the way to the right to force a release and then readjust or fix something, I don't know but that basically what i did.

The other guys, Scrip7 or HAILERs could probaly help more than me, and I only just learned this stuff, I only know it applies to FC's , I have no idea what an FD is like. Good luck.

 

I have found new hope in this board, as place where real problems can be resolved and ideas, information and experiences traded openly and efficiently. I'm glad that we are able to come together like this without incident.

I'm very happy with the progress that we made with my car. I was so frustrated and perplexed by the whole thing that i was really second guessing my commitment to these cars..the idea of my brand new motor not running right was devastating, but thankfully, with some good, sound mechanical advice from some helpful fellow rotor heads i was able to get my idle back.

 

looks like its a sticky bac valve, same thing happnd to my n/a

http://s164.photobucket.com/albums/u...t=MOV02283.flv

i got a new one and it fixed itself!

 

look at that.... that does indeed look like alot like what i was seeing. But I think my BAC valve is okay, it checked out with ressitances and 12v click, seems to have an effect on idle now as well..but that does look very similar, I'm glad you were able to get yours fixed as well.

 

Have you checked your BAC valve lately!! when I swap throttle bodies on my car I had a simuliar issue with the idle. Come to find out that I forgot to connect the wire to the BAC valve. I also found out that my valve thingy on the back of the dynamic chamber had a leak. I fixed leak and connected BAC valve wire and issue was gone. Hope this helps a little!!

Chris

 

I think I can speak for everyone who has helped you in this thread. We're glad you didn't give up on it. It would have been easy to throw in the towel and give up, only to have to put up with an irritating idle. I know I have a renewed understanding about the thermowax and the idle adjustments. The FSM can be very vague on many topics. I am tempted to do a writeup concerning high idle/ rolling idle with pics. Seems like a popular symptom, along with rough idle and stalling.

 

As far as diagnosing the thermowax itself, we have established that these basic fundamentals should exist:

There should be adequate flow of hot coolant through it to extend it's plunger.

The cam position should be adjusted with the plunger screw to establish full release of the fast idle cam from the roller at normal operating temp.

According to the FSM, the fast idle cam roller should line up with the first mark at a coolant temp/ throttle body temp of 77 degrees.

Therefore, once we have confirmed hot coolant at the thermowax unit, if it is not possible for the fast idle cam to fully release from the roller by adjusting the plunger screw, the thermowax should be replaced.

 

It makes sense to me to try to confirm that there is good flow of hot coolant, adjust the plunger screw so that the roller is away from the cam when fully hot, and see what position the cam is in when the engine cools down overnight. If the cam will move enough to create a fast idle, so be it. It's a backwards approach compared to the FSM, but you get the idea.

As for the correct fast idle speed on a cold engine, there is a spec given for clearance between the primary throttle blade and the bore, but no rpm spec. In my opinion, if you can obtain a fast idle speed of 1800-2000 rpm, that works for me, and if the hot idle comes down to 750ish, you're done.

As for tps adjustments, bottom line is that the throttle lever should be touching the base idle speed screw (the one with the locknut) before making any changes in adjustment.

Then the dashpot can be adjusted to allow gradual closing of the throttle but not to prevent the throttle lever from touching the base screw.

 

*****My understanding is that the 77'F matching mark on the fast idle cam should line up with the center of the roller when the engine is just started, once fully warmed up the fast idle cam should fully seperate from *************

Something to remember here. That rollpin that the cam rides on actually has a bushing on it that should spin. That helps the cam seperate from the roll pin. It's something you can overlook. I only realized it was there when NZ madea comment on it on another thread.
A little oil on it might help or something to free it up to roll is if's frozen in place. Just a small thing that can help.