jeremy

iTrader: (1)

ok, i tried to find my old thread that some wanted my to post to after i tinkered, but i can't find it. so to rehash.

91 na

car goes through warmup fine, stays at 1.5-1.8k rpms until temp gauge reaches operating temp then stays arond 1-1.1k rpms as if it would slowly lower as temps came up. this idle was always pretty steady, no hunting. i could take the car and slip the clutch to push it down past the 1k mark and then it would drop and start idling at 750rpm as required, still steady. also if i reamed on the car, shifting at redline, it would automatically drop to 750.

as a side note, it would surge when braking it down to 750 before pushing the clutch in, as if he motor was fighting to go past the 1k mark.

so as someone suggested a vacuum leak, i pulled a small vacuum line behind the motor last night and the idle rasied to 1k from the 750 i'd set it at using the clutch to knock it down. so believing i have something sticking, i take the plastic off the throttle body. the bottom plate was a bit dirty so i clean it up with a towel and some wd40 (yes i have small hands). go to put it back together and start it. its idling at 1.5k and i can't knock it down. so of course i'm pissed because now its worse. so i start poking in the bay and find i'd knocked a vacuum line off in the process. plug it in and idle lowers to 1.2k. so looking around again i notice one of the large vacuum lines under the intake look loose. i can wiggle it a little to easy on the plastic so i pull it, car dies. big vacuum leak, lol. so i go inside and get the dish detergent and use the "bmx grip" trick, smear a little on the inside, put them back on and go inside to let it dry. come back out and wiggle the really loose one. won't move under slight pressure so i leave it at that, climb in, start, same **** before i pulled it off. so i just grab the 32 oz mallet and start wailing on this mfer. ok, thats what my thoughts were doing. so as i'm revving it i notice it that i could do something that i was able to do before i took of the plastic intake. if i was to try and hand shove the throttle closed and hold it, it would eventually drop idle w/o using the clutch slip trick. however i used to be able to do it easily, now it would only do it occasionally and always sit at 1k. then the bastard decides to start the idle hunt ****. like 1.2k to 1.8k, rev, rev. james looks at me and says tps. ^%$@^#*&^#^%@&%^#&^@^$@$^!!!!!!!!!! dammit. so he tells me where it is but i'd already guessed it. thing is, i have two. i had also taken and pused these in with my fingers and it affected the car in no way.

now driving it after leaving his house, it has stayed at the 1.5k until warm and then can be knocked down to 1k. so it seems that whatever i did in removing the intake plastic and cleaning the lower plate made the problem worse. it hasn't done the idle hunt again though. just that once. i know this is a long *** post and some might want to go get a popcorn and coke, maybe read it over again. its just pissing me off as i have no true target to work with. my blown struts and falling apart exhaust are easy. i look at it and see its broken. this things like a hardy boy's mystery.

jeremy

iTrader: (1)

okay, anyone know were i can get a pink neon kit and some blacked out altezzas?

88 SE

OK check out my thread about idle problems:

https://www.rx7club.com/forum/showth...hreadid=155755

Try doing the section for "Bad idle speed" first, that sounds like your problem. BE SURE TO SET YOR TIMING

Check for vacuum leaks too. to quote SonicRat:
"I must agree, vacuum leaks are the #1 cause of idle issues! "



Lemme know what happens.

jeremy

iTrader: (1)

ok, i did the starter fluid spray to check for vacuum leaks and have found nothing. when idling high(1.5k), i can pull a vacuum line(smaller) and it doesn't affect it. but i can still drag the engine down with the clutch and it will stay at 800~900 AND ITS ROCK SOLID. if you pull a line, it will raise the idle. wtf is going on here. this is becoming very annoying. PLEASE READ THE FIRST POST. this is not a timing issue. if there is a vacuum leak its well hidden. i figured after i was done with the extra strength starting fluid that i might end up getting some weenies since i drenched the damn thing. no response. i did this at the 1.5k idle and the 800~900 idle. and whih tps do you set, narrow or extended range? are there two on all second gens. and for the love of god someone answer something besides a boost controller thread. or "my steering wheel keeps falling off, should i tighten the nut?" where are the good tech guys?

HAILERS

You NEED to download the fsm at http://www.iluvmyrx7.com the Fuel section. Read about the Fast Idle Operation and the setting of the Fast Idle Cam, Cam Adjusting Screw, Cam Roller etc.

Prior to the above, remove the throttle body so what you read will make some sense. It helps to have the throttle body in front of you while try to understand the text.

While you have the throttle body off, clean the crud behind the throttle plates. Don't go wild. Just clean the crud. That crud is not your major problem, but needs to go.

SonicRaT

iTrader: (6)

Yeah, I'm with Hailers. I'm thinking more along the lines that the fast idle cam is sticking/thermowax isn't doing it's job and so forth.

88SE: I still back that statement, those damned vacuum leaks haunted my life for months!

HAILERS

Well, another tack is to warm the car up fully. Let idle. Pull the bac's plug off. Stop the engine. Restart the engine. Does it still run strange? Fully warm, hot engine.

If the car dies without the aid of the bac, then set the idle using the fsm as your guide. Then do the paragraph above again and tell us if the strange idle is there with the bac disconnected.

RYLMONKEY

try adjusting the throttle stop screw. its real small. not sure where it is on na's but on my t2 that what was my culprit. might be around the back of the TB.

jeremy

iTrader: (1)

i pulled the bac plug while it was running but didn't think about it shutting it off and turning it back on. as for removing the tb, i don't have money for gaskets so i'll have to be smart. where is the thermowax? someone said this before and i can't find it. i've been using the fsm off of fc3s.org fuel/vacuum section.

ryl monkey, i'll take a look at that.

like i said, it got worse after removing the plastic from the throttle body. i'm wondering if i'm fighting multiple culprits here. i' going to try and work on it tonight. luckily james has a pc in his *heated* garage so i can post back as i work. thanks a ton for the ideas guys. its getting old using the clutch to kick the idle down everytime i come to a stop.

RylAssassin

LOL.

HAILERS

Where is this plastic thing you talk about??? And why not try starting the car, getting it fully hot, and pulling the bac's plug off, shutting it down, restarting the car, and tell us what happened.

There is no gasket for the throttle body, at least not on a series four. The thermowax is on the aft side of the throttle body. On a series four its almost impossible to examine it without removing the throttle body.

The

jeremy

iTrader: (1)

the plastic elbow/tube that attaches the airbox to the throttle body.

another note. i let the car sit outside idling for 15 or so minutes while i talked to a friend, came out and noticed it was rock solid at 750. start to drive and its doing the same thing it used to. hang up right at a touch over 1k and then with the clutch, pop it down and it would idle at 750. as i ran the car and the heat left the engine bay it started to get higher again. so i'm guessing in removing the two large vacuum lines coming off the intake tube, they are loose enough now to have a slight vacuum leak. where as when it is heated enough, it seals off and is ok. so that means i just have something hanging as i previously thought. now do i have to go to a dealer and order those large hoses as autozone had nothing vacuum wise that big?

jeremy

iTrader: (1)

bac unplug results: idled about 100rpm higher. still could use the clutch to knock it down but idled at about 1.1k. left alone about 1.7k.

looked at taking off the tb but has a coolant line going to it. at least that's what it looks like.

pengarufoo

I havent read all your posts as it's kindof all over the place, but are you able to get out of the car and turn the throttle to it's 'idle' position when it's idling high? like the throttle is binding on something? If so it might be your dashpot inconsistently keeping the throttle off it's idle stop... I just pulled all this junk off my s4 na and it's simplified things a whole bunch and nothing bad has been noticed yet...

HAILERS

Well, the bac theory is OUT. Usually the idle will drop a touch if the plug is taken off, and the idle is below 750.

So. Here's my other thought. The thermowax has a piston that extends when the water is hot. It retracts when the water is cold.

When the water is cold, it retracts, letting something called a fast idle cam to once again contact a roll pin. As the water gets even colder, the cam rides higher on the roll pin.

The consequenses of riding higher on the roll pin, is for the throttle plates to be cracked even further open...........increasing the idle speed.

So your hesitant to take the throttle body off due to this and that.

So I think you can probably afford a new thermostat. Go get one from MAZDA. Get the gasket too. Get the highest temperature thermostat that you can buy from MAZDA. Install the thermostat. Problem solved. Do not break the two studs holding the thermostat housing in place. When reinstalling them, put some anti seize lube on the threads. Maybe even some axle grease.

Problem solved. I wonder if this car even has a thermostat. If this does not solve the problem, remove the throttle body and follow the fsm and readjust the thermowax/fast idle cam etc.

jeremy

iTrader: (1)

had the tb off. i just worked with it and the coolant lines. its bahind me warming up. good thing james has a black keyboard and mouse, huh? how much am i looking at for a thermostat? and it seems to be a bandaid fix. isn't the thermowax (which i didn't see unless it the thing the coolant lines are going into) the problem?

HAILERS

Your throttle body does not have one of these..... https://www.rx7club.com/forum/attach...postid=1416963

jeremy

iTrader: (1)

? these? it has a thermowax. i just looked at the damn thing now that i have it back together and looked at your post.

jeremy

iTrader: (1)

ok, folks. my throttlebody has a thermowax, so mark that in the side of the brain that remembers rx7 stuff. i backed the cam to where it barely engages and now not much of a problem. it will still hang at around 1k sometimes. i believe that might be the idle catch contraption needs backed off some as its old and stiff now. i am getting some rpm hunt between 500-900 rpm sometimes too. as for cold start, my right foot does that now. far better then getting pissed at the idle everytime the car is under 2k. car is far easier to drive now. so how expensive is that contraption to replace?