missfire at idle...

My naturally aspirated 87 Toyota Supra has a missfire at idle. It goes away under any amount of throttle. It also seems to have little to know top end power. I'm thinking it's gotta be a timing issue but haven't had a chance to check the timing on it. Just wanted to see if anyone knew off hand what might be causing that.

Don't know if the knock sensor might cause that problem but I know it's not working as well.... it wasn't even connected when I bought the car but even after I plugged the wire harness to it it didn't change anything.

Let me know,
Josh

Okay so I finally figured out where TDC is and I checked the timing. My car's idle is too high and I didn't think about that before I started checking it. It idles between 1200-1300rpm. I'll have to correct that before I can set it correctly. It was idleing at something like 35-40 BTDC instead of 10 where Toyota recommends. Course with it idleing so high you can't really correct it. I'm not sure what the timing should look like at those rpms. That much advance still seems too high. I'm thinking about turning it down a bit tomorrow morning to see if maybe that will also lower the idle and possibly correct my missfire at idle. If anyone has a suggestion let me know PLEASE!

Dang Reighn Jake just left my house ill call him and get him to check this out.

Cool. I'd appreciate that if he might know what I should do.

I just caled him he will be checkin it in a bit

shveet

Did you buy that car from Shawn? He had an MKIII in crestview and sold it...

Have you checked your codes? Check this out, if you own a Supra, this site should be on your favs ALWAYS... This is the Cygnus TSRM on line... *TSRM = Toyota Supra Repair Manual* Hayne's manual is ok for referance, but the TSRM is the Supra bible...

http://www.cygnusx1.net/supra/TechTips/engine_error_codes.aspx

I bought it from a guy named Eric who also happens to have an SR20DET 240sx.

I've skimmed through it a bit but a lot of stuff is missing from that and some of the stuff I need isn't legible. Like recalibrating the TPS... the diagrams are so small you can't see what the heck to do. I also checked my CEL codes. I have 4 on right now. One is on for the TPS, one is on cause the speedo doesn't register, another for A/C failure, and the last one was knock sensor incomplete circuit or failure.

I just scanned through the TSRM again and can't seem to find out how to set the idle and recalibrate the TPS. Do you know where those are at in there?

check with the guys from VW water werks 850-586-3601 George Low
or
george@waterwerksmotorsports.com

I know George. I have talked to him a few times when I was working at the VW place. But they aren't a Toyota oriented group why would you recommend them?

I was wondering the same

Ah, code 51... Read this ---> http://www.supramania.com/forums/showthread.php?t=46793

I can pretty much help you with anything involving Supras and the 7M motor... But I suck at explaining... Im better at doing... I will recommend though, if you seriously intend to keep this car and do anything remotely above and beyond a tune up and oil change, you should join www.supramania.com and read read read... Supramania was originally started to cater to the MKIII community, recently, we have expanded to share space for the MKIV crowd... There is a TON of information on the MKIII and 7M... Even recalibrating TPS's, lol...

I can adjust the TPS, and I cna do alot of other things, I just cant tell you what screw to turn, and what voltage it should be and all that... Its more in my head ya know... I CAN tell you that when you are ready to boost and are ready to start modifying, let me know... I can definately help you with that and give you some good ideas and power combos... I know SOME people on here think all motor is the best, but those of us that are boost junkies know whats really up... :D:D

I like all motor and boost. I've tried both and find them both to be quite satisfying. I do intend to keep this car. Over the last 2 years I've had a bad habit of project car hopping but this one is a keeper.

I have never seen supramania.com. I have tried supraforums.com and thesupraforums.com but both of those suck. Most Supra owners have had the pleasure of talking to don't seem to actually know how to fix the cars. They all know how to make them go faster and that's pretty much it. So I REALLY appreciate you taking the time to talk to me and directing me to that other site. Hopefully as time and money become available I can get this thing in tip top shape. The car itself is in great shape minus a paint job and several little mechanical/cosmetic querks.

I'll skim through that link and learn as much as possible and I'll get back with you when I get stuck again.

Thanks!
Josh

i dont know where the hell i got that maybe because of the electronic butterfly type tps or something i dont know i had to be drinking or something..... my bad.

It'll be aight. I just though maybe you knew something I didn't, like maybe George also knew something about Supras too. I'm sure Reign_maker can tell me everything or mostly everything I'd need to know. He's already pointed me in the right direction.

Supraforums sucks balls... I go there for the OT and Florida sections... I avoid the MKIII section because I get tired of reading and answering the SAME questions OVER AND OVER!

SF is owned and run by vendors, specifically MVP Motorsports... The mods there are tyrants... They have sites that of you type thier name and post it, the name will be blocked, like this: www.********.com Its absolute BULLSHIT! You cant post Ebay links, ANYWHERE... Also, since you own an MKIII, there you are less of a person... MKIIIs arent Supras to them, and even if you have a Supra like mine, its still a piece of shit to the MKIV guys... You'll learn that of the hundreds of car families, Supras are the ONLY ones that have a division between generations... You'll never here new school honda guys rippin on old skool honda guys... I absolutely HATE the devide in the supra nation, but its there, its real, and all you can do is hold true to your family... My family is the MKIII...

Here's teh TRUTH about the families...

MKIV owners tend to be yuppies, trust fund babies, white collar office cubicle types... When it comes to modding and working on thier cars, thier idea of working on a car is writing out a check or swiping a credit card...

MKIII guys tend to be more blue collar... We work on our own cars... We get dirty... We have grease under our nails... We are the first ones to help another Supra guy out, and all we expect in payment is a cold beer... I love being a part of the MKIII family... And trust me, if I WANTED to, I could own an MKIV, but why do I want a catfish? *MKIVs look like catfish in the front*

Join Supramania, look for me there, I have the same screen name... Im a Super Mod on the site, so you already have a gaurdian angel there if you have any trouble...

I wanna help you get your car where you want it... Sucks you live in C-view, lol... But if you really need my help, I can work it out and help ya...

Jake

Your dang right it sux I live it Crestucky. There is never anywhere to hang out and when you need complicated automotive advice, everyone just recommends you take it somewhere.

As for the MKIII family, your actually the first MKIII owner I've spoken to that actually seems decent and also knows a lot about them. Everyone else automatically points you to the TSRM without even thinking about the question. I've skimmed through the TSRM and find it pretty much useless. I had an original Mitsubishi owners manual for a Chrysler Conquest TSI (aka Mitsubushi Starion) that I owned and it ROCKED. It had step by step everything. The TSRM is just diagrams and doesn't explain very much.

I'm gonna try dropping my timing down quite a bit tomorrow. I probably could have done it Sunday but I was too lazy to switch outta church clothes and into some rags. I don't have to go to work until 12:00 tomorrow. I also wanna try recalibrating the TPS. I figure since I have both TPS lights on that that is a pretty good indicator it's blown or the wiring harness has shorted somewhere. I gotta get a multi-meter so I can check it. The funny thing is she runs like a champ with the TPS outta wack, the knock sensor not working, and the timing way the heck off, LOL!! (except for the missfire ofcourse)

Well I'm starting the SupraMania membership off a little rocky. Now that I'm registered I can't post anything....

Your acct has to be approved by admin before you can post...

I may have a TB you can have, gotta check my parts box, lol....

Well you don't need to "give" me one. If it comes down to it I might buy it from you. I'll have to wait until pay day to get a mutli-meter and see whether it's actually bad/good.

By the way how hard is it to remove the tranny and change the clutch? I've done a tranny removal by myself before but I am just curious cause I may have to replace my clutch soon... and my sincros are going out too.

Brian and I installed my tranny by ourselves, its not TOOOO bad... BUT, if you plan on going with the 7MGTE, I would skimp by with the tranny you have until you can upgrade it... The thing is, the NAs came with the W58 5sp trannies and the turbos came with the R154... The R154 is practically bullet proof... The only real weak link is the thrust washer, and its not so much the strength of it, but the lubrication, aka: heat... The W58 is pretty weak... There are R154's runnin around holdin over 1000hp... I wouldnt put more than 350hp through a W58...

And I would GIVE you the part, because thats how I roll... Lemme see, I can give you the part for free or I can charge you $30 for it... Is it worth me making $30 for helpin a fellow supra guy? No... I'd just give it to ya... Trust me, you'll see... I've gotten so many free little parts from people and givin free parts to people, its part of being a true car guy... We help out when we can... Like, I sent a guy in Norway some motor mounts because he got ripped off... In turn, someone GAVE me a head because mine had a crack... We help each outher out, thats what makes us a community...

Well alright. I'll let you know if it comes down to replacing it. Are the clutches interchangable between the W58 and the R154? I'm most likely gonna need a new clutch within a month or 2 of I continue driving it. I am planning on bleeding the clutch whenever I get a chance to see if that helps. Probably not cause it looks like it has fresh fluid in the reservoir. Actually I could make a whole list of crap that will need replacing.

master cylinder
clutch
tranny
knock sensor probably
knock sensor wiring probably
front wheel bearings
all 4 struts
speedo cable
light behind instrument cluster(the headlight switch broke off and the guy I bought it from rigged it all to a toggle switch and a metal bar in place of the original headlight/turn signal switch... and now the instrument cluster light stopped working for some reason)
and a bunch of interior stuff.

damn reighn you make me wish i had a poopra.


































with a ELIS_JAUN!!!!!!!!!!!

Well I just finished retarding the timing about 15 degrees..... After I started looking at the distributor and actually began moving, I realized the moron who owned it before me had advanced it ALL THE WAY! I retarded it back down to 10* before TDC llike it should be stock and it ran great at idle. Took it for a drive and.... ahh man..... sure enough it's got problems. It drives fine as long as you don't get into it. If you give it more than maybe an inch of throttle it bogs and it won't rev past say 3,300rpm. It's like it's absolutely STARVING for gas. So I took it home and bumped it back up to 15* before TDC and it runs a little better but still the same problem, just not as bad. Ticks me off too cause with it advanced it missfires and sounds like crap. With it set to stock it sounds GREAT and runs like a swiss watch except for leaning way the heck out. My only idea is the TPS is bad and it's not giving it any gas, or the knock sensor not working right is retarding the heck out of it under throttle.

I also noticed my idle went down to about 900rpm with the timing set back to stock. Now at 15* it's idleing about 1000rpm. When I had it set to stock it stopped missfiring though. I mean if you were standing in front of the engine you could still here a pop in the exhaust every 4-5 seconds but when you were in it and or driving it there was no missfire at all.

Clutches arent interchangable from R154 to the W58...

The is a knck sensor rewire you can do, it helps solve a lot of the false KS warnings... The thing with the NAs is they only have one KS, where the turbos have 2...

A few things I would check: vacuum leaks, make sure you dont have ant dry rotted vacuum lines, make sure they are all hooked up and routed properly... Also, check your AFM, if its whack, it'll throw everything off...
Dude, if you lived in FWB, I'd be all over that car for ya...