Engine Misfire Problem.

[Guest TXSupra]

Hoping someone can shed some light on this.. it's been a four year Cluster fuck.. anyways.. I gave the history of the car.. to my knowledge. Hope someone can help out..

 

1993 Toyota Supra N/A - stock automatic with 150,000 miles (estimated) on Odo.

Got the car back in 2006 ran perfectly, i loved it to death. AND THEN, someone pulled out in front of me while i was doing about 45mph-ish... collision, not my fault. $7,500 worth of damage (mainly airbags). All this happened Friday October 13th, 2006 (my luck ha..) Anyways, got the car out the body shop after about 2 or so weeks.. and it was running extremely slow, i was getting beaten by 18-wheelers on acceleration. Fiddled with the Plugs...it worked fine again. Sometime mid-2007, the tachometer went crazy (bouncing between 3k-6k RPM, and ran like crap...exhaust was hot, but not red hot)

 

Anyways it bounced around mechanic to mechanic (bad idea, but being in a small town.. no one knows how to work on Supra's, if they even know what it is) Toyota couldn't help me, they had no idea what the hell it was doing.. So this year..we got it running (changed the fuel pump, ECM and spark plugs recently) and it starts .. now it misfires.

Current symptoms are:

- Misfire

- White smoke upon start up (possibly because it hasn't ran right in God knows how long.

- Black smoke upon backfire.

- Will not rev past 4,100RPM (acts like it has a rev limiter)

- Won't hold idle until it's a little warmed up (idles low, sounds like it's cammed)

- Seems to be cutting out while revving it and backfires when doing so (too much or too less fuel)

- Exhaust gets hot (it only got red hot once)

- Seems hesitant, acceleration still sucks.. gotta floor it to get it to move some.. and will die when you let off gas in D, but not when it's in L, 2 or R.

- Sometimes when i stop revving the engine, it doesn't catch idle and dies.

 

Ideas include: Fuel Injectors, Fuel Filter. Toyota doesn't have the machine to do a diagnostic.. so getting the code is out of the question.

 

That's the story of my Supra.. i want to get the car fixed because it's been inoperable for 4 years now and i would like to fix it up some time soon, instead of fixing it.

[jagman]

"Toyota doesn't have the machine to do a diagnostic.. so getting the code is out of the question."

you can do this yourself at the diagnostic plug and read the codes -see FAQ

[David P]

The rev counter runs from a sensor in the distributor, if this has been damaged in the shunt, not only will the rev counter be upset, so will the ECU.

 

Try swopping the distributor and/or inspect the connecting clip and wires to check this before spending any more money.

 

P.S. Welcome to the club.

[SupraDan24]

Try looking here matey Clicketh the linketh

[Guest TXSupra]

The distributor or distributor rotor? I didn't change the distributor cap last time I did the tune up..back in like 2007/2006 lol, i thought it might be some sort of weird sensor.. i'll also have to check on that diagnostic plug and reading the codes of whatever Jagman was talking about..

[Guest TXSupra]

Holy crap, i'll have to try this.. i was wondering why there was some weird wire looking item in my diagnostic car under the hood bridging two parts together.. i thought they were by passing something, but apparently.. it's a diagnostic tool? Odd, i'll have to try this tomorrow. I wrote down all the codes so it's all on my computer.. i'll try this tomorrow and hopefully can come up with something.

[David P]

Undo 3 screws and take a look, it's not rocket science.

There is a castleated ring with sensor pick up and a connecting clip for the wires.

The diagnostic codes will confirm if this is the prob, but as you stated it ran O.K. for a while after you had fiddled with it, that suggests to me the problem could be here.

 

Edit: Pull that link wire out of the diagnostic port .

 

Edited December 19, 2010 by David P (see edit history)

[Scooter]

is it worth the guy checking the 1st cat to see if its partially blocked?

[Lbm]

To the Op, please when posting in tech, use a more specific title. Thanks. Threads with bad titles can be deleted.

[JustGav]

Holy crap, i'll have to try this.. i was wondering why there was some weird wire looking item in my diagnostic car under the hood bridging two parts together.. i thought they were by passing something, but apparently.. it's a diagnostic tool? Odd, i'll have to try this tomorrow. I wrote down all the codes so it's all on my computer.. i'll try this tomorrow and hopefully can come up with something.

 

Which pins where bridged in the diag port?

[Branners]

To the Op, please when posting in tech, use a more specific title. Thanks. Threads with bad titles can be deleted.

 

and cut out the swearing. It is not necessary.

[Guest TXSupra]

Undo 3 screws and take a look, it's not rocket science.

There is a castleated ring with sensor pick up and a connecting clip for the wires.

The diagnostic codes will confirm if this is the prob, but as you stated it ran O.K. for a while after you had fiddled with it, that suggests to me the problem could be here.

 

Edit: Pull that link wire out of the diagnostic port .

 

http://www.mkivsupra.net/vbb/attachment.php?attachmentid=124329&d=1292762813

 

Thanks, i've taken this piece of already. I will check the codes today.

 

is it worth the guy checking the 1st cat to see if its partially blocked?

 

That's what i was thinking it might at least help my situation some.

 

To the Op, please when posting in tech, use a more specific title. Thanks. Threads with bad titles can be deleted.

 

Rodger that, i'll keep that in mind next time i post. And the swearing portion also.

[Guest TXSupra]

Which pins where bridged in the diag port?

 

I can't really say for sure which ones, without looking inside the diagnostic port. However it was on the far right side, if your looking at the car from the engine compartment. It was done like that from a shop it had been at. I thought that it was just some small town rigging. Turn out later on a find out it's Toyota Supra Diagnosing. Anyways, i'm going to go out there and see what i can dig up. Hope this works!

[Guest TXSupra]

BTW, how can i change the title to be more specific? Trying to help out here not aggravate anyone Or if a moderator can do that, go for it. I'll be back later for an update.

[Guest TXSupra]

Okay UPDATE:

 

I grabbed a bobby pin and put it in the E1 and TE1, i have a constant (non-blinking) CEL. When i start the car, at first the CEL and the MIL come on, revving is very hesitant. Then moments later the MIL goes away, but the CEL stays constant and revving is a lot easier however still hesitant. Still seems to have something limited the revving to 4,100RPM. Idles at 500RPM. and the weird odd connector i saw before was bridging the OX1 and OX2. Guessing oxygen sensors. Anyways, i haven't been able to figure out this self-test diagnostic thing, but i'm pretty sure somewhere there was a table for what set off the CEL and MIL.. not sure entirely..

[Guest TXSupra]

No one wants to help here when the self-diagnostic system isn't working?

[heckler]

Okay UPDATE:

 

I grabbed a bobby pin and put it in the E1 and TE1, i have a constant (non-blinking) CEL. When i start the car, at first the CEL and the MIL come on, revving is very hesitant. Then moments later the MIL goes away, but the CEL stays constant and revving is a lot easier however still hesitant. Still seems to have something limited the revving to 4,100RPM. Idles at 500RPM. and the weird odd connector i saw before was bridging the OX1 and OX2. Guessing oxygen sensors. Anyways, i haven't been able to figure out this self-test diagnostic thing, but i'm pretty sure somewhere there was a table for what set off the CEL and MIL.. not sure entirely..

 

not sure whats going on there, but with E1 and TE1 bridged, with the ignition on (but engine not running), the MIL/CEL lights should blink regardless...

[David P]

From memory, I think the terminals you bridge are E1 and TE1, then count the blinks, which gives reference to the fault codes that you can find in the w.s. manual or on here with a search.

We have given all the help we can, until you do some work yourself.

[Guest TXSupra]

Yeah, it should blink.. but it doesn't. both the CEL and the MIL stay on constantly.

 

When i first started this morning i didn't get any blink or any CEL or MIL light. But i took out the panel itself and connected the connectors better. and then started the car. the CEL and MIL came on, i turned the car off...they were blinking then.. but more seemed like a shorting out type of blink. I tried to count the amount of blinks just in case (they were blinking extremely fast). But they were fast and there was a long pause were the light stayed on.. so it took a long time and i'm pretty sure it was shorting out. BUT regardless of what i thought it was a short in the wiring or not.. i wrote down the blinks..i got: 1, 7, 2, 5, 1, 2, 2 and did weird stuff. THEN after that craziness...i started it.. CEL and MIL again.. i cut it off. turned off igition, then turned it in two clicks.. and both the CEL and MIL stayed lit.. constantly.. never blinked or nothing.,

[Guest TXSupra]

So i recently learned that the Supra's don't rev past 4,100RPM.. i've been out of the Supra game for a little bit..as you can tell. So now it's a case of misfire.. i'll start with the mechanical misfire.. and work toward getting a tune-up on her.

[heckler]

Yeah, it should blink.. but it doesn't. both the CEL and the MIL stay on constantly.

 

When i first started this morning i didn't get any blink or any CEL or MIL light. But i took out the panel itself and connected the connectors better. and then started the car. the CEL and MIL came on, i turned the car off...they were blinking then.. but more seemed like a shorting out type of blink. I tried to count the amount of blinks just in case (they were blinking extremely fast). But they were fast and there was a long pause were the light stayed on.. so it took a long time and i'm pretty sure it was shorting out. BUT regardless of what i thought it was a short in the wiring or not.. i wrote down the blinks..i got: 1, 7, 2, 5, 1, 2, 2 and did weird stuff. THEN after that craziness...i started it.. CEL and MIL again.. i cut it off. turned off igition, then turned it in two clicks.. and both the CEL and MIL stayed lit.. constantly.. never blinked or nothing.,

 

the entire on board diagnostics is driven by the ECU... something dammn wierd going on....

[heckler]

So i recently learned that the Supra's don't rev past 4,100RPM.. i've been out of the Supra game for a little bit..as you can tell. So now it's a case of misfire.. i'll start with the mechanical misfire.. and work toward getting a tune-up on her.

 

They rev upto 6800!!

[heckler]

just an idea... what if the cam belt has jumped a tooth?

[Guest TXSupra]

I dunno what they rev too (a guy on the other Supra forum said they won't rev past 4,100rpm in the automatic in neutral/park) .. i haven't driven the car in working condition since 2008.. so lol i forgot. I was thinking about if the cam belt jumped a tooth during the misfire/rev/fiesta. I agree Something WEIRD is DEFINITELY going on.. i have yet to figure this problem out.. and when the dealership tells you "i don't know" something's wrong lol. Unfortunately, i don't know how to check to see if it jumped a tooth, the can't be diagnosed...a $4,000 Diagnostic Machine went crazy when it connected to the Supra.

[jagman]

Disconnect the battery, and reconnect again , this clears previous faults .

Then start engine , run the gear box selector up and down a couple of times then go through the fault codes again .

Looks like someone was looking at the oxy sensor - good call

you can check the sensor voltage at the diagnostic plug -

After such a long time the sensor is probably fubar , a replacement , non genuine one can be spliced in using the original Toyota connector .

If the o2 sensor is shot you get large overfuelling and plugs will be black and can misfire