ACIS and a vaccumm leak?

[Chris R]

So I definitely get that surge at 3500 to 3800 rpm. After some research, it seems my ACIS is screwed. I need to e-mail the owner, but I have a JDM transplant motor. Possibly an ex cresseda motor, but the throttle body was changed out. What's the best way to go about fixing the ACIS?

Any pics would be greatly appreciated, as I have no idea what I'm looking for here.

I read that it's best to clean the intake, and if I were, how would I go about doing that without damaging anything?

But my car also idles funny, it revs a couple hundred rpms, between 500 and 700, in a rhythmic fashion. It doesn't do this all the time.

I have to charge the fuel pump from an interior switch before I start the car. Not sure if that would have much do it with it once I got it started. It was put there by the previous owner, I've only had this car about a week.

I probably need to check for a leak or two hoses that got switched up. What's the best way to go about doing that?

I

 

[Chris R]

Alright, did some error checking.

I got codes 21 - Oxygen sensor

41 - Throttle Position Sensor

and 43 - Starter

Could the throttle position sensor be responsible for the rough idle?

 

[CRE]

A problem with the TPS can cause idle issues, but it's usually related to the IDL switch in the TPS (see code 51). Test the TPS and see if it's properly calibrated... if it is you may just want to replace it. It is a wear component after all.

 

[Chris R]

It's probably got some mileage on it, but I'm thinking of replacing it anyways.


Anyone got any info on ACIS? I posted over and Supraforums and no one said much there either. If there's a post on this that I'm missing, please link me to it, but I searched.

 

[AJ'S 88NA]

It's probably got some mileage on it, but I'm thinking of replacing it anyways.


Anyone got any info on ACIS? I posted over and Supraforums and no one said much there either. If there's a post on this that I'm missing, please link me to it, but I searched.

There's some info on it in the NA stickies.

 

[al.]

Anyone got any info on ACIS? I posted over and Supraforums and no one said much there either. If there's a post on this that I'm missing, please link me to it, but I searched.

not much practical info, but there's a wiki entry that briefly explains its function and actuation - ACIS

and hello, i'm new here :drink1:

 

[CRE]

Start by verifying that all of your vacuum lines are routed properly and that there are no leaking lines. Personally, I would just replace them all so i could be sure in the future that they're going to be in good shape. A vacuum leak can also cause the roaming idle, but I'd look at the TPS first.

Look at the following for routing information.
http://www.cygnusx1.net/Supra/Library/EPC/291410/catalog.aspx?F=1708&P=2


Fix the error codes too. I don't know if any of those will cause the ECU to not activate the ACIS VSV, but I promise they're not helping.

 

[Chris R]

I just wanted to give a quick update. I ordered a new TPS. On my first test drive, it ran like a bat out of hell. The torque in the low range was all there. Perfect.

And then I realized that somehow we forgot to plug it in.

So I plugged it in, and the idle was a bit rougher, and it seems like it does not want to rev above 2000 rpms.

I ordered mine from rockauto parts. It was for the 7mge FI (fuel injected?). The 7mge listed as MFI did not have a TPS.

I read that the 89+ were different from the pre 89's, and this one is about 90 degrees off. So I'm guessing that's part of the problem.

Aside from that, what is the throttle position sensor's job? There is a manual throttle cable, just like in my 5SFE Celica, so I'm just wondering if it affects the air/fuel ratio, or what. It seemed to run better without the TPS, but I'd rather not play around and harm the motor.

 

[HommerSimpson]

I just wanted to give a quick update. I ordered a new TPS. On my first test drive, it ran like a bat out of hell. The torque in the low range was all there. Perfect.

And then I realized that somehow we forgot to plug it in.

So I plugged it in, and the idle was a bit rougher, and it seems like it does not want to rev above 2000 rpms.

I ordered mine from rockauto parts. It was for the 7mge FI (fuel injected?). The 7mge listed as MFI did not have a TPS.

I read that the 89+ were different from the pre 89's, and this one is about 90 degrees off. So I'm guessing that's part of the problem.

Aside from that, what is the throttle position sensor's job? There is a manual throttle cable, just like in my 5SFE Celica, so I'm just wondering if it affects the air/fuel ratio, or what. It seemed to run better without the TPS, but I'd rather not play around and harm the motor.

Did you calibrate the new tps? And yes you need it.. it tells the ecu were the trottle is... everything works together telling the ecu what it needs to do... screw 1 thing up and you can wack the afr out and run lean and next thing you know you got holes in pistons....

 

[Kckazdude]

The TPS only differentiates between turbo and NA. There is no year break in them.
Be sure to install the TPS as outlined in the TPS.

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=101

 

[Chris R]

Did you calibrate the new tps? And yes you need it.. it tells the ecu were the trottle is... everything works together telling the ecu what it needs to do... screw 1 thing up and you can wack the afr out and run lean and next thing you know you got holes in pistons....

I thought I had read that the TPS doesn't need calibration, it just needs to be installed. I'll search again.

The weird thing is that it ran great without the TPS plugged in. I dunno, but the old one is on there now just to keep it drivable.

Come to think of it, given how the old TPS caused me to loose some of that low end punch, what I'm guessing is that the old TPS is wrong. I looked at the newer TPS and compared it to one of the pictures in a thread around here, and the "tabs" set vertical, pointing to the screw holes. The old one is 90 degrees off, and the tabs set horizontal.

So the new one is probably the right part after all, it just may need calibration.

The TPS only differentiates between turbo and NA. There is no year break in them.
Be sure to install the TPS as outlined in the TPS.

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=101

Sorry, I missed this post. It was in one of the threads I found in search, but it said that there was a difference in that the throttle position sensors were 90 degrees off from one another. And that describes exactly the difference I'm seeing in the two here in front of me.

I somehow did not connect the dots when I read about the thickness gauge between the throttle stop screw and the screw lever. I guess I'm not seeing if that is for calibrating, or just to check and make sure the throttle cable assembly is acting properly.

 

[jetjock]

1) The TPS needs to be calibrated to the TB.

2) Not weird at all the engine runs good with it unplugged. It's supposed to. However if you have the wrong one plugged in (or the right one but not adjusted) it'll be a different story.

 

[Chris R]

I still have no calibrated it, I'm planning on grabbing my dad's multi-meter tomorrow and doing it.

We had another throttle body that came with the car, and that seemed to work perfectly with the new TPS, so we swapped them out. The throttle bodies were the same size, and all the lines hooked up, it just seemed that the TPS was the only difference.

On the old throttle body, if I installed the new TPS by sliding it in with the wire connector facing up at a 90 degree angle, and then sliding it clockwise, the sensor would lock the throttle wire in such a way so that it would not move. We had to hold the throttle level at full throttle to install the sensor, and that did allow it to move.

When the new sensor was connected, the car would stop revving at about 1.8k rpms and it would just decel down to 1000.

Now, on the new throttle body, it acts just like it did before before I touched anything on the car at all. I tried adjusting it a bit by hand with the motor on, but never really got it to act right.

It still lacks a bit of low end, and on the highway in 5th I still get a delayed (two or three seconds) throttle response.

So I'm going to attempt to calibrate it tomorrow and see where that gets me.

Part of me wishes I would have just left the damn thing unplugged the first time I put the new TPS on the older throttle body. For some reason the car ran beautiful, and pulled great. And then I decided to plug it in and it all went to hell. :3d_frown:

Looking at the symptoms, I had attributed those to a bad TPS, along with that code 51 I was getting. If anyone has any other recommendations feel free to chime in.

 

[Chris R]

Another update.
We're trying to calibrate it now. Hooking an ohm meter up to it, I've been slowly moving it clockwise until it deflects, and then moving it ever so slightly counter clock wise until the meter goes back down to zero.

We don't have a feeler gauge, and that's a problem. But I figured by calibrating it I'd just try and get it as close as possible.

The issue, however, is that since adjusting it (my first time was pretty sloppy, not gonna lie) it has been misfiring. I kept the car running and the TPS plugged in and tried moving it throughout it's range, and it misfired the entire time.

Any ideas? I realize that I need a feeler gauge to do this right, but would that throw it off far enough to cause a misfire?

-edit- Pulled the plug closest to the radiator, there's oil in there. Meh. Guess that explains the lost oil. - removed oil, misfire went away, sort of. It'll idle great for a couple of seconds, at about 700 to 800. It'll slip down to 600 and idle rough, and it'll alternator a bit. Ont he highway now, it's kind of like it gurgles in certain RPM ranges. The delay in the throttle is still there.

So I think I'm dealing with a couple problems here, and not just the TPS. Timing may also be an issue, we have not checked that.

It'd be a good idea to change out the valve cover gasket since some of the screws were loser than what they should be, and there was oil in the spark plug closest to the front of the car. The plug furthest to the back did not have that much oil in it, nor the second one in line. We have not checked the ones underneath the throttle body yet.

For anyone reading this, hopefully I'm not confusing the hell out of you. I promise my thoughts are not as random as they appear on here.

 

[Chris R]

I mentioned earlier that we switched out the throttle bodies. I think the newer throttle body that we switched in might be connected to the misfire problem.

-edit- Pulled the plug closest to the radiator, there's oil in there. Meh. Guess that explains the lost oil. - removed oil, misfire went away, sort of. It'll idle great for a couple of seconds, at about 700 to 800. It'll slip down to 600 and idle rough, and it'll alternate a bit. On the highwa it gurgles in certain RPM ranges. The delay in the throttle is still there.

I took my dad out with me on this second run, he said that gurgle I was describing is a pretty bad misfire.

Before the highway run with my dad, we cleared the ECU. It seems that whenever we clear the ECU, on the first time starting up it idles incredibly high, around 2500. On the highway it acts normal, no huge misfire issues are prevalent. When the car is shut down and started a second time, the misfire returns and the issues becomes worse when the car is being driven.

I'm wondering if this has anything to do with the MAF sensor, and if that is related to the throttle body. We hooked all the hoses up to the newer throttle body right, so I don't believe that is an issue.

As for the oil that was found in the spark plugs, I think that just compounded the problem of the misfire, it definitely was not the source. Car still seems to run rich too, the older throttle body was pretty dirty and black on the inside.

There could also be an ECU problem in there somewhere. The previous owner said that the guy who had the car before hand put, I quote, a "plug and play ecu" from Toyota in the car. Who knows. I think I need to replace that anyways, since I have no idea how that thing is tuned, if it's chipped, or whatever.

On top of all this, the TPS still hasn't been calibrated 100% correct. I plan on picking up some feeler gauges at an auto parts store tomorrow. We're gonna throw the older throttle body on, with the old TPS, calibrate it and see if that does anything whatsoever.

 

[AJ'S 88NA]

I mentioned earlier that we switched out the throttle bodies. I think the newer throttle body that we switched in might be connected to the misfire problem.



I took my dad out with me on this second run, he said that gurgle I was describing is a pretty bad misfire.

Before the highway run with my dad, we cleared the ECU. It seems that whenever we clear the ECU, on the first time starting up it idles incredibly high, around 2500. On the highway it acts normal, no huge misfire issues are prevalent. When the car is shut down and started a second time, the misfire returns and the issues becomes worse when the car is being driven.

I'm wondering if this has anything to do with the MAF sensor, and if that is related to the throttle body. We hooked all the hoses up to the newer throttle body right, so I don't believe that is an issue.

As for the oil that was found in the spark plugs, I think that just compounded the problem of the misfire, it definitely was not the source. Car still seems to run rich too, the older throttle body was pretty dirty and black on the inside.

There could also be an ECU problem in there somewhere. The previous owner said that the guy who had the car before hand put, I quote, a "plug and play ecu" from Toyota in the car. Who knows. I think I need to replace that anyways, since I have no idea how that thing is tuned, if it's chipped, or whatever.

On top of all this, the TPS still hasn't been calibrated 100% correct. I plan on picking up some feeler gauges at an auto parts store tomorrow. We're gonna throw the older throttle body on, with the old TPS, calibrate it and see if that does anything whatsoever.

You have to take care of one thing at a time. Yes the oil in the plug wells will cause a miss fire. Hard to tell how old the plugs are I'd replace them while you're at it and check your wires.

And the TPS has to be calibrated right our you will get the high idle and other problems you mentioned. The TB will get dirty due to the PVC hoses and poor maintainance, I.E. air filter, long oil changes etc.

 

[Chris R]

You have to take care of one thing at a time. Yes the oil in the plug wells will cause a miss fire. Hard to tell how old the plugs are I'd replace them while you're at it and check your wires.

The plugs are pretty new, according to the previous owner. Same with the wires. It might be a good idea to change them. Before I do though, I want to try and get the TPS calibration out of the way so I don't spend a lot of money chasing ghosts. Will a TPS cause a miss, or can I just rule that out of the misfire problem?

And the TPS has to be calibrated right our you will get the high idle and other problems you mentioned. The TB will get dirty due to the PVC hoses and poor maintainance, I.E. air filter, long oil changes etc.

I think the previous owner did do a decent job of maintenance. The high idle only happens on the first start up after clearing the ECU. Aside from that, it may idle at 1000 at it's highest.

 

[AJ'S 88NA]

The miss is most likely from the oil in the plug wells. If it's a lot yu have to make sure you get the ends of the plug wires clean also.

 

[jetjock]

The TPS is not the cause of your misfire. Plus you're putting WAY too much focus on setting it. The feeler gauge thing is not critical and is mainly for emissions. Just set it using code 51 and as long as you don't end up with a 41 afterwards move on to what's really wrong with the engine...

 

[Chris R]

The miss is most likely from the oil in the plug wells. If it's a lot yu have to make sure you get the ends of the plug wires clean also.

We cleared most of the oil out of the plug wells. We'll go back and clear off the wires a bit more thoroughly. The plugs were almost completely underneath oil at first. But we cleared a good 90% of it out. It's no longer touching the plugs.

The TPS is not the cause of your misfire. Plus you're putting WAY too much focus on setting it. The feeler gauge thing is not critical and is mainly for emissions. Just set it using code 51 and as long as you don't end up with a 41 afterwards move on to what's really wrong with the engine...

Gotcha. I'll check for codes again. From reading the threads about adjusting the TPS, I got the impression that it had to be nearly perfect or the car's performance would suffer.

I've adjusted it to the best I can, so you're right, it's time to move on. If the TPS will not cause a misfire then we'll take a better look at the plugs when we switch throttle bodies back and see if we can move on from there.