johnathan1 said:
Wiring harness is 'reasonable'. not very good, but not too bad.
I redid most of the wiring going to the cps, afm and all sensors in the water housing area. I also rewired everything going to the coil pack.
Bad idle when warmed up
- Thread starter Back2Basics
- Start date
Wiring harness is 'reasonable'. not very good, but not too bad.
I redid most of the wiring going to the cps, afm and all sensors in the water housing area. I also rewired everything going to the coil pack.
The problem you're having sounds very similar to mine. It starts up good and as it warms up the idle is normal. Go for a 5-10 minute drive though and come to a stop and the idle is erratic.
It's missing, shaking, sputtering, etc. If I stomp on the gas in neutral and bring the motor to about 5000rpm it will go back down to a normal idle.
Sometimes the idle is fine when I stop sometimes it's rough. It's like something is turning on or off that's causing it but I have no idea what. I'm getting a knock sensor code (52) and o2 sensor (21). I've put in 2 different o2 sensors but I'm still getting the code, and I still have to look at the knock sensor wiring. But it's not nescessarily throwing codes when it's idling rough.
I'm just curious, if those of you with this problem try the same thing as I do...which is stomp on it in neutral till 5000rmp and let it go, does your idle smooth out?
It's missing, shaking, sputtering, etc. If I stomp on the gas in neutral and bring the motor to about 5000rpm it will go back down to a normal idle.
Sometimes the idle is fine when I stop sometimes it's rough. It's like something is turning on or off that's causing it but I have no idea what. I'm getting a knock sensor code (52) and o2 sensor (21). I've put in 2 different o2 sensors but I'm still getting the code, and I still have to look at the knock sensor wiring. But it's not nescessarily throwing codes when it's idling rough.
I'm just curious, if those of you with this problem try the same thing as I do...which is stomp on it in neutral till 5000rmp and let it go, does your idle smooth out?
Anth505: Sometimes it does smooth out but most of the time it just dies.
I suggest you take care of the code 21 first. Maybe redo the wiring. I did a lot of rewiring and it sure helps. Even when it doesn't solve your problem right away, it helps you pinpoint the problem. Every repair tells you that the piece you repaired is okay. So the problem will be somewhere else.
Do the following:
- Clear your codes
- Check your wiring, especially the wires for the O2.
- Check (and set) your TPS as it is a well known problem for dying engines after revving.
I suggest you take care of the code 21 first. Maybe redo the wiring. I did a lot of rewiring and it sure helps. Even when it doesn't solve your problem right away, it helps you pinpoint the problem. Every repair tells you that the piece you repaired is okay. So the problem will be somewhere else.
Do the following:
- Clear your codes
- Check your wiring, especially the wires for the O2.
- Check (and set) your TPS as it is a well known problem for dying engines after revving.
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Update for my own problem:
I changed my AFM too.
In combination with the new CPS this seems to do the trick quite well.
Car idles fine @ cold idle, and drives great when cold or hot. (a/f 14.5 @ cruise).
Only thing is now that at hot idle it won't go below a/f of 16.
It's not bogging or idling rough anymore, and if it wasn't for the fact that I have a wideband sensor I'd think it idles great judging by the sound and the vibriating of the engine.
The 'user' value on my (zeitronix) wideband meter tells me that its value is about 0.03. I guess it should be around 2.60 or something like that to indicate that this is normal.
'User' values lower than 2.5 indicat that it is trying to do something right? leaning out/enriching ???
Someone had this problem before? or knows what the h#ll the ecu is trying to do? (and even better: WHY it's doing it!)
I changed my AFM too.
In combination with the new CPS this seems to do the trick quite well.
Car idles fine @ cold idle, and drives great when cold or hot. (a/f 14.5 @ cruise).
Only thing is now that at hot idle it won't go below a/f of 16.
It's not bogging or idling rough anymore, and if it wasn't for the fact that I have a wideband sensor I'd think it idles great judging by the sound and the vibriating of the engine.
The 'user' value on my (zeitronix) wideband meter tells me that its value is about 0.03. I guess it should be around 2.60 or something like that to indicate that this is normal.
'User' values lower than 2.5 indicat that it is trying to do something right? leaning out/enriching ???
Someone had this problem before? or knows what the h#ll the ecu is trying to do? (and even better: WHY it's doing it!)
^ The 'User' value turns out to be the Vf value.
So when driving the Vf value is 0.03 constant. Also when idling it stays that way and at very rare moments it jumps to 0.00 and back again to 0.03.
I looked it up and 0 means the ECU thinks that I'm running rich so it's leaning it out. But it shouldn't! A/f when driving is a bit lean but reasonable. Idle it still is at about a/f of 16.1
So what could cause the computer to think it's running lean when in fact it doesn't ?
Please :1zhelp:
So when driving the Vf value is 0.03 constant. Also when idling it stays that way and at very rare moments it jumps to 0.00 and back again to 0.03.
I looked it up and 0 means the ECU thinks that I'm running rich so it's leaning it out. But it shouldn't! A/f when driving is a bit lean but reasonable. Idle it still is at about a/f of 16.1
So what could cause the computer to think it's running lean when in fact it doesn't ?
Please :1zhelp:
thevork said:
You could have a broken wideband o2sensor, did you run the engine a lot with the zeitronix powered off?
We can swap our sensors to check
My engine doesn't die after I rev it, it smooths out. Lets say I drive up to a light and stop and this time the car decided it wants to idle rough (it doesn't do it every time). If at idle and in neutral, I mash the gas pedal to the floor and bring the rpm to about 5000, when it drops back down, it goes back to a normal smooth idle. That has to indicate something.
It's as if the car responds by saying "oh yeah, I'm supposed to idle now, here ya go!". I was just wondering if that symptom was the same for others with this problem. If someone on here knows why the car would react that way, it might save alot of time by not having to check things that wouldn't cause that.
It's as if the car responds by saying "oh yeah, I'm supposed to idle now, here ya go!". I was just wondering if that symptom was the same for others with this problem. If someone on here knows why the car would react that way, it might save alot of time by not having to check things that wouldn't cause that.
Problem Solved. I removed the EGR and replaced it with block off plates. The problem is now resolved! It was either the EGR vacuum modulator or the EGR itself. Either way, all is good. Hope this helps.
Good to hear Anthony! So i guess that means no more having to rev to 5000 rpm for no reason huh?Anth505 said:
lol...well it wasn't for no reason. It smoothed out the idle quite nicely. But now it runs smooth all the time on it's own...makes me happy!
I just got my car to idle perfiect. I changed the afm, then loosened the screw on the afm body then I backed out the idle screw on the throttle body. u might want to try the idle screw then. if that don't fix it try the afm.
Good for you man! Hope it stays that way.
Call it coïncidence, but I just finished swapping my complete wiring harness out for a better one today. After resoldering about 60 wires (the new harness was out of a '92 supra and I have a '89) it fired right up and now I also have a perfect idle.
For everyone who wants to swap out an engine wiring harness for a newer one: Don't do it. I ended up resoldering just too much wires. Everything seems okay now but the antilock light comes on after touching the brake once.
Ah well... can't have it all at i guess
Call it coïncidence, but I just finished swapping my complete wiring harness out for a better one today. After resoldering about 60 wires (the new harness was out of a '92 supra and I have a '89) it fired right up and now I also have a perfect idle.
For everyone who wants to swap out an engine wiring harness for a newer one: Don't do it. I ended up resoldering just too much wires. Everything seems okay now but the antilock light comes on after touching the brake once.
Ah well... can't have it all at i guess
the antibrakke light was on in my pass 3 mkiii s. i finally got it to turn off by plugging the wire that come out of a little hole under the hood by the fuse box area, it seem like a speed sensor or brake senors wire from the drvers front wheel.the light is now off. it use to come on once in a while because the clip are old and would not hold tight. let me know this is the problem.thevork said:Good for you man! Hope it stays that way.
Call it coïncidence, but I just finished swapping my complete wiring harness out for a better one today. After resoldering about 60 wires (the new harness was out of a '92 supra and I have a '89) it fired right up and now I also have a perfect idle.
For everyone who wants to swap out an engine wiring harness for a newer one: Don't do it. I ended up resoldering just too much wires. Everything seems okay now but the antilock light comes on after touching the brake once.
Ah well... can't have it all at i guess
That was not the problem with my car.
I forgot (didn't see) to hook up the rear speed sensor wire to the engine wiring harness.
after plugging it in all errors and lights disappeared as snow for the sun.
thanks
I forgot (didn't see) to hook up the rear speed sensor wire to the engine wiring harness.
after plugging it in all errors and lights disappeared as snow for the sun.
thanks