so what do you want me to do? i understand the thermowax may be bad but is their a way to strabilize the idle for now??

my little bro has a temp gun i can use tomamarow morning before work.

 

DON'T TOUCH THE STOP SCREW YET!!!!.....CLEAN THE THROTTLE BORES AND BLADES FIRST!!!.......sorry for the caps hehe.

 

okay, I'll do that tommarow afternoon when i get home from work, but is there any way to get it to keep an idle for now??

 

Does your BAC have an adjustment screw?....try that first. I noticed you said the BAC was unplugged when you had your low idle. With it plugged in, try adjusting it.

 

Borrow the temp gun and with the engine fully warmed up, aim it at the bottom of the thermostat housing. I'd like to see at least 175 degrees. Then aim it at the thermowax unit and report back.

 

thats what i was gonna do but once i got out to my car, which is like 200ft from my house , i heard this noise in the woods behind me and tunred around to see these big green eyes looking back at me about 50 ft away and coming closer.....hahaha i ran in here cause we have a bear than comes almost nightly, now and i didn;'t want to meet him up close......without a shotgun anyways...

so yeah I'll plug the BAC back in and try to get a stable idle around 750. Hopefully i can get it to stay put. then I'll let the eninge warm up and check the temps on the thermostat and the thermowax unit and let you know whats up from there. That'll happen tomarrow morning.

Then I'll clean the throttle body if necessary, i just gave it a good once over a month or so ago trying to solve this same problem.


Thanks I'll let you know whats up.

 

If you cleaned it a month or so ago, then it is probably ok, depending on how thorough you were. With your BAC plugged back in, I bet it idles better. And thanks again for being so cooperative. I am impressed. So many people don't listen or follow directions. Go back and read the first paragraph of post #77. I'll check back in tomorrow sometime.

Oh, best of luck on that bear. They like to eat upholstery, much like puppies chew window screens.

 

this is where i'm at as of tonight...we'll see how it goes in the morning...hold on one minute for video

 

Still hear some misfiring in your idle. Is your engine streetported? Did you try the propane trick?....also how long had it been running when you made this video?...the reason I ask is look at your temp gauge.....that sucker should be just under half way up the scale when fully warmed up, hence my suspicion of t-stat.

 

I have a slightly off-topic question that maybe you or Hailers could help me with. I just figured out today how to upload my Photobucket pics into my posts, but I have noticed several people have edited their pics to include things such as circled or highlighted parts, using different colors for each, which is very cool. Where can I find editing software like this that I can import my pics into?

 

it was only running for a minute or two, i haven't even ran it longer than 10 mins in a while, i don't think the t-stat has ever even had to kick over in the past couple days when tryong this stuff rally, i mean the upper hose is cool pretty much, if i can get it to idle better i'll let it heat all the way up though..

 

ms paint on your pc, in accessories near the calculator and stuff.....or photoshop but everyone has ms paint on the windows computer, go to the start button n your task bar and go to programs to accessories to ms paint and open your pic in their and then draw on it and save it again.

 

Cool. I'm familiar with ms Paint, never thought to use it for this purpose. Thanks big time.

 

After the BAC plug is reinstalled, and if it does not idle very well or keep a high enough idle. you could turn that STOP screw to increase the idle. I'd try to keep the idle speed below 1000 rpm. After 1000 rpm problems happen with the ECU increasing the timing which makes the rpms shoot up quite a bit.

I'm talking short time/makeshift idle so you can get from here to there until you find time to work on it in a more calm manner. Make sure the TPS is reconnected AND after making adjustments, look at the PALM and set the TPS again to read 20 percent. Your going to have to adjust the TPS after you make other adjustments later on. By the way, NEVER make a TPS adjustment unless the engine is fullly hot.

IF this is a 87/88 and you have a puffy idle (as in a pooh, pooh, pooh), you can go to the variable resistor and turn it in a rich direction and usually that will get rid of the puffy/occasional missing sound and it'll idle smoother. Get the engine HOT before making adjustments. By HOT I mean normal operating temps.

Variable resistor screws have stops on each end. Do not try to overcome the stops. The screw turns only about 3/4 of a full turn.

One thing I think you have to agree on. The very high idle was because the throttle plates were being held open too much. I'm understanding that now the *idle* is more in the 500-700 range???? or 300-500 rpm range??? At least you can now work on the thing and make adjustments that make a difference in the idle.

I also admit I have SCROGGED your water thermowax setting all to hell to prove the throttle plates were the cause of the 1500 rpm idle. That can be overcome by reaind the FUEL section of the online FSM which shows how to set the waterthermowax/fast idle cam etc. JUst try to keep the idle down to a reasonable figure. Basically below 1000rpm for sure.

 

I usually see a picture and right click on it. A list is shown and I click on SAVE TARGET AS............ Then save it in My Pictures. Then I go to MY PICtures and right click on that pictue and select SEND TO............and send it to MSPAINT where I scribble on it, make lines and generally deface what was once a fine pictue.

I have no camera and don't plan to buy one. I scan most of my jps on.....the scanner. I've done rotor housings on the scanner and intermediate housings. Big deal I guess.

 

Okay.

With the BAC plugged back in it will hold around 1200 now with a slight burble every couple secs. But the BAC is set with the screw all the way to the right to keep it down to even 1200. Also for some reason the TPS is now reading 5 while at rest instead of 16, I'll adjust it to 20 in a minute after this post.

So I let it warm up for like 15 mins and shot the temp gun at the t-stat and the thermowax:

T-stat housing - 175'
Thermowax - 125' as best as I could get to it with the gun




Thats rpm, air flow, tps and coolant temp shown on the palm.


I tried the propane trick and the idle did increase slightly and the burbling was reduced as well. I'll now try to find more leaks anywhere I can with the propane.

I might try to turn that variable resistor screw slightly to see if that makes a difference.

I am familiar with the section on the Fast Idle cam in the book, I have been looking at it here along with all of your guys info, so I will reset it at some point after we are done here. Do you think I am going to have to replace the thermowax unit itself?? I mean we are adjusting a lot of things to get it back to normal but what made it just start doing this one day out of the blue??

 

When I started it up this time though it was idling lower even went down to around 750 but was wishy washy, like didn't kno where to stay exactly. It did start to idle right arounf 800-900, as I was pushing on the throttle linkages and when I tried to close it more the idle did drop a little more down to 700 for a bit.

I just tried to adjust the tps to twenty and the car will stall now if I don't give it gas. I put it back to 5 and the car still wants to die now. If i can get it back to holding an idle even at 1200 or 1000 or whatever I'll try to find vac leaks w/ propane but I can't keep it running with the gas and look for leaks at the same time....

So now what??

 

So I just tried moving the tps towards 20 ( don't know exactly where it was, due to lack of palm this time) and backing the BAC screw out, well after like 4 full turns on the BAC screw it is idling better, it will almost hold itself up at 700 or so but will die if i don't give it just a touch of gas everyonce in a while. but it is much closer to holding its own now, I also don't hear as much popping or burbling....

 

I'm gonna have to leave for work in like 2 mins, but I should be home home early today around 5pm or so , I'll check in to see what you guys think....Thanks.

 

Glad to see lots of progress being made. And please, if you can keep from doing it, try not to mess with the stop screw/ locknut. It is a precise adjustment, not intended to be messed with, and a real pain in the *** to get right once you've messed with it. It should be possible to have a stable idle without ever touching that screw, the only exception being if you had a big streetport with reduced vacuum due to changes in port timing. As long as the BAC is working correctly, let's tackle mixture first, get a smoother idle, then make your final speed adjustments. With the throttle resting on the stop screw (fully closed), set your tps per the FSM. Then, grab your propane torch and cut the nozzle off the end of it (after the valve) so you can attach a hose to it. Torches are cheap, so a minor sacrifice. Remove the brake booster hose at the intake and attach your propane hose. Open the valve slightly and start the engine. Try to get it to idle with however much propane you need to get there. Adjust the BAC screw for best idle. Let us know what happens so we can proceed.

 

ok, will do, I'm off to work now, tha ks again for your help.

 

I'm not sure yet if we need to replace your thermowax just yet. Let's get a stable idle at the right speed first and then we can adjust the fast idle cam position, fast idle speed and make a final determination on the thermowax. The thermowax gets it's coolant supply from a port on the rear iron. I did study the coolant flow chart in the FSM, and it appears, in my opinion, that the coolant hasn't absorbed as much heat at the coolant hose port as it would by the time it reached the thermostat housing, so it might be acceptable to read a lower temp at the t-wax housing. Obviously, there isn't a spec for coolant temp for the t-wax, so it may be one of those situations where you install another one and see what happens. I have a couple of them I can send you if you need one.

 

https://www.rx7club.com/forum/attach...hmentid=220193

**NOTE: Pay no attention to the words in RED. They were written for another thread.

Remember the screw you initially turned all the way in???? IT sits on top of the water thermowax piston. Sooooooo, I'm suggesting that if you have a tea pot with a spout, you could boil a tea pot of boiling water.

Then pour that water over the exterior of the thermowax. Now look at the piston with a mirror and see if it extends out of it's body further than when it was cold.

Just a thought. I do believe even pouring boiling water over the exterior will make the piston move outwards. If it moves, then mabe for *some reason* the water passage coming to the water thermowax is clogged or the outlet from the throttle body is clogged.

 

okay more good suggestions. I'll try some things out today and report back and let you know whats happening. Thanks guys,

 

so, i have reached a fairly good idle now, between adjusting the BAC valve. the tps and the fast idle cam screw and taking some slack out of my throttle cable it holds pretty steady around 850.

Thermowax when cold:

Thermowax when hot:

Throttle stop resting on hard stop screw when hot, I never touched this screw:


I also never tried to adjust the actual fast idle screw, just the one for the cam, should i have tried that instead? I don't know, but it seemed to work. Though the thermowax thing doesn't seem to be sticking out that much further when hot than when cold, it does extend just not much..

I also turned that variable resitor screw just a small bit to the right after everything else and the idle seemed to pick up and smooth out a little. It was like a balancing act between the BAC, the tps and the fast idle screw that i had originally screwed all the way to the right. But it seems better now, it won't stall and doesn't surge at all anymore.

I'm still gonna look for vac leaks and just keep going over the motor replacing little things and trying to get her in top shape..

I have another short video I'll post, here's a pic of my two rx's though for the meantime: