Auto Xray results....help
Thread Starter
Melting Slicks
Joined: Aug 2000
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From: Springfield MO
Auto Xray results....help
Help me diagnose a poor tip in and low end bog.
Desired Idle 700 rpms ( I wish it were 800...Ed Wright chip)
Actual idle ~730 (it varied from 690 to 750...compliments of the cam)
IAC steps 0 (but with ac/heat on it was 26....fastchip tech says shoot for 30)
Learned IAC steps 56 ( whats the difference between the actual and learned?)
If I lowered the Idle down around 680 or so I could get my IAC steps up around 50-60 but its does not want to idle that low, I get a horrific knock coming from the bellhousing area (single mass flywheel I assume/hope)
I tried unplugging the IAC motor itself and it at first it read 104 steps and then worked its way to 40 :confused: Without power why was it working?
I'm strugglin' here, and help will be appreciated.
Desired Idle 700 rpms ( I wish it were 800...Ed Wright chip)
Actual idle ~730 (it varied from 690 to 750...compliments of the cam)
IAC steps 0 (but with ac/heat on it was 26....fastchip tech says shoot for 30)
Learned IAC steps 56 ( whats the difference between the actual and learned?)
If I lowered the Idle down around 680 or so I could get my IAC steps up around 50-60 but its does not want to idle that low, I get a horrific knock coming from the bellhousing area (single mass flywheel I assume/hope)
I tried unplugging the IAC motor itself and it at first it read 104 steps and then worked its way to 40 :confused: Without power why was it working?
I'm strugglin' here, and help will be appreciated.
Thread Starter
Melting Slicks
Joined: Aug 2000
Posts: 2,009
Likes: 1
From: Springfield MO
Re: Auto Xray results....help (AS84)
Here's my hypothesis:
After toying with it some more I believe my desired idle is programmed too low. The computer wants it to idle at 700 rpms, my car simply won't idle that low. I have a friend who says he can change the idle on my chip to 800 easily, should I give it a whirl?
The lower I idle it down the more IAC counts I get, therefor If I set the desired idle higher I should be able to lower my actual idle enough to achieve 30 Iac steps right?
After toying with it some more I believe my desired idle is programmed too low. The computer wants it to idle at 700 rpms, my car simply won't idle that low. I have a friend who says he can change the idle on my chip to 800 easily, should I give it a whirl?
The lower I idle it down the more IAC counts I get, therefor If I set the desired idle higher I should be able to lower my actual idle enough to achieve 30 Iac steps right?
Le Mans Master
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From: And on the fifth day, subpoenas were served to Obama senior staff
Re: Auto Xray results....help (AS84)
OK, I don't think your minimum idle has been set properly. You need to go through the setup proceedure in the tech tips section. You should be getting IAC counts even to keep it at 700, so it needs to be set up properly before you can determine what else needs to be done.
Your IAC has not control of idle right now. You just can't adjust the minimum air screw w/o going through the setup proceedure, now it's going to be hard to get that car to settle down to 450 RPM but see how close you can get. Then you will see some reasonable IAC counts and you can set your TPS.
Good Luck
Pete
Your IAC has not control of idle right now. You just can't adjust the minimum air screw w/o going through the setup proceedure, now it's going to be hard to get that car to settle down to 450 RPM but see how close you can get. Then you will see some reasonable IAC counts and you can set your TPS.
Good Luck
Pete
Le Mans Master
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From: And on the fifth day, subpoenas were served to Obama senior staff
Re: Auto Xray results....help (AS84)
Also: is that chip for exactly this combo or just a generic chip? Your 90 is a speed density system and will not respond well to cam changes (well at least heavy cam changes) w/o custom programming. Not just idle, but the chip will have to be messed with to match that cam and other changes in the engine.
But to start you need to set that minumum air adjustment best you can (in diagnostic mode) and then the tps and see where you are. You should be back at getting some IAC counts at idle. Then you can see who knows how to program your ecm for any mods in the engine.
Remember there is no idle adjustment on these engines, only the ecm can set idle. The screw on the TB is minimum air and just establishes a baseline for the ecm.
But to start you need to set that minumum air adjustment best you can (in diagnostic mode) and then the tps and see where you are. You should be back at getting some IAC counts at idle. Then you can see who knows how to program your ecm for any mods in the engine.
Remember there is no idle adjustment on these engines, only the ecm can set idle. The screw on the TB is minimum air and just establishes a baseline for the ecm.
Thread Starter
Melting Slicks
Joined: Aug 2000
Posts: 2,009
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From: Springfield MO
Re: Auto Xray results....help (AS84)
The tech man at ed wright said my cam wasn't big enough to cause my car not too idle at 700 rpms, but he eventually agreed with me that it was too low and that raising it up would be a good idea. WTF, I guess I'll have my friend re program the desired idle. If I sent it back to fastchip I probably wouldn't have it for 2-3 weeks.....my car runs like poo without it, therefore it would be a lot easier to drive across town to my friends house and take care of it myself.
Le Mans Master
Joined: Dec 1999
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From: And on the fifth day, subpoenas were served to Obama senior staff
Re: Auto Xray results....help (AS84)
I don't know enough about cams to help. But you do need to set that minimum air adjustment first. It takes 5 minutes tops, and then you can see if the ecm / iac can hold idle or if it hunts too much.
Also consider as you go through it that there may indeed be another problem such as a vacuum leak or messed up TB that needs cleaning or has a sloppy shaft. But set the minimum air correctly and then the TPS and see if it will idle. Right now your IAC /ECM is not controlling idle.
To answer another early question you had, the scanner is reading the steps the ecm is sending to the IAC to try and control idle. If ECM is trying to reduce idle and IAC is fully extended counts will be 0. 0 IAC counts are bad because the ecm cannot change idle when it wants to, and the relationship to the TPS will be off as the throttle blades are extended past where the ECM thinks they are.
Also consider as you go through it that there may indeed be another problem such as a vacuum leak or messed up TB that needs cleaning or has a sloppy shaft. But set the minimum air correctly and then the TPS and see if it will idle. Right now your IAC /ECM is not controlling idle.
To answer another early question you had, the scanner is reading the steps the ecm is sending to the IAC to try and control idle. If ECM is trying to reduce idle and IAC is fully extended counts will be 0. 0 IAC counts are bad because the ecm cannot change idle when it wants to, and the relationship to the TPS will be off as the throttle blades are extended past where the ECM thinks they are.
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Thread Starter
Melting Slicks
Joined: Aug 2000
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From: Springfield MO
Re: Auto Xray results....help (PeteL)
. But set the minimum air correctly and then the TPS and see if it will idle. Right now your IAC /ECM is not controlling idle.
I unplugged the EST plug and my car died, and i'm willing to get that you are 100% correct about the ECM not controlling the idle.
Le Mans Master
Joined: Dec 1999
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From: And on the fifth day, subpoenas were served to Obama senior staff
Re: Auto Xray results....help (AS84)
Wait, wait, wait! :D
So you can set minimum air; did you get it to 450 RPM?
What was your base set RPM and what was the ECM idle when all done?
Then tell us about the noise the ZF is making (from single mass).
So you can set minimum air; did you get it to 450 RPM?
What was your base set RPM and what was the ECM idle when all done?
Then tell us about the noise the ZF is making (from single mass).
Thread Starter
Melting Slicks
Joined: Aug 2000
Posts: 2,009
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From: Springfield MO
Re: Auto Xray results....help (PeteL)
So you can set minimum air; did you get it to 450 RPM?
Nope I got it down to 700. If I go lower will the ecm pick the idle back up? Hmmm, I wonder.
What was your base set RPM and what was the ECM idle when all done?
My desired idle was still 700 rpms and my actual was fluctuated from 680-720.
Then tell us about the noise the ZF is making (from single mass).
If the idle gets too low an annoying knocking sound comes from the rear of the bellhousing. Its not rythmatic just random.
Thanks for being so helpful! :cheers:
Nope I got it down to 700. If I go lower will the ecm pick the idle back up? Hmmm, I wonder.
What was your base set RPM and what was the ECM idle when all done?
My desired idle was still 700 rpms and my actual was fluctuated from 680-720.
Then tell us about the noise the ZF is making (from single mass).
If the idle gets too low an annoying knocking sound comes from the rear of the bellhousing. Its not rythmatic just random.
Thanks for being so helpful! :cheers:
Le Mans Master
Joined: Dec 1999
Posts: 8,540
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From: And on the fifth day, subpoenas were served to Obama senior staff
Re: Auto Xray results....help (AS84)
No,nononono :lol:
I mean when you put in the paper clip and get the IAC to seat fully, then pull the IAC connector, then set minimum air adjustment. This should be to about 450 RPM (what you set the screw to), the IAC is disconnected so ECM cannot control idle. Will it go to 450 w/o stalling after following this proceedure? This is what I was calling "base" idle, actually minimum air idle adjustment point.
After that you re-connect IAC and ECM should control idle using IAC and you should be able to scan the IAC counts necessary for the ecm to obtain the desired idle. This is what I was calling "ECM idle" or the idle that the ecm was controling.
[Modified by PeteL, 8:50 PM 1/24/2002]
I mean when you put in the paper clip and get the IAC to seat fully, then pull the IAC connector, then set minimum air adjustment. This should be to about 450 RPM (what you set the screw to), the IAC is disconnected so ECM cannot control idle. Will it go to 450 w/o stalling after following this proceedure? This is what I was calling "base" idle, actually minimum air idle adjustment point.
After that you re-connect IAC and ECM should control idle using IAC and you should be able to scan the IAC counts necessary for the ecm to obtain the desired idle. This is what I was calling "ECM idle" or the idle that the ecm was controling.
[Modified by PeteL, 8:50 PM 1/24/2002]
Team Owner
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From: SE NY
Cruise-In II Veteran
Re: Auto Xray results....help (PeteL)
That's correct, you need to set the base idle to 450rpm, with the IAC motor disconnected.
Then trim the TPS to it's setpoint (if your's is adjustable).
Then trim the TPS to it's setpoint (if your's is adjustable).
Thread Starter
Melting Slicks
Joined: Aug 2000
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From: Springfield MO
Re: Auto Xray results....help (65Z01)
O I C
I'll try to get it idled down the 450 rpms without it stalling. Here's another element to throw in to the mix. my tach is off therefore setting it to 450 rpms is guess work. I'll go out and try it again tonight and I'll re post the results.
65Z01- its about time you showed up :cheers: I've been visisting your site while doing this stuff, great site man....lotsa info.
I'll try to get it idled down the 450 rpms without it stalling. Here's another element to throw in to the mix. my tach is off therefore setting it to 450 rpms is guess work. I'll go out and try it again tonight and I'll re post the results.
65Z01- its about time you showed up :cheers: I've been visisting your site while doing this stuff, great site man....lotsa info.
Team Owner
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From: SE NY
Cruise-In II Veteran
Re: Auto Xray results....help (AS84)
Thanks AS84; been back in NY about 3hrs now and had to get onto the Forum.
BTW, maybe you can use your AutoXray to get accurate tach values to set that 450rpm base idle. And remember it doesn't have to idle for very long there, you're only setting the base throttle plate position with that idle screw.
BTW, maybe you can use your AutoXray to get accurate tach values to set that 450rpm base idle. And remember it doesn't have to idle for very long there, you're only setting the base throttle plate position with that idle screw.
Thread Starter
Melting Slicks
Joined: Aug 2000
Posts: 2,009
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From: Springfield MO
Re: Auto Xray results....help (65Z01)
BTW, maybe you can use your AutoXray to get accurate tach values to set that 450rpm base idle. And remember it doesn't have to idle for very long there, you're only setting the base throttle plate position with that idle screw.
Melting Slicks
Joined: Apr 2001
Posts: 2,112
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From: Ca.
Re: Auto Xray results....help (AS84)
If you've got a healthy cam and mods you won't be able to use the traditional method of idle adjust. Get the target idle where you want it on the chip-then scan it and turn the idle up or down until you have about 20 to 30 iac counts without the ac on. As for the single mass flywheel- they are noisy buggers to start with, and if it idles too low it just gets noisier. To shut it up you may want to try 850rpm idle.
Oh yea-saw you've got a SR; it shouldn't be near as bad as a miniram, but the tip in bog-there's a couple of tables that miniram owners have had success with- I beleive it was the pump shot vs. diff. tps and the tps theshold for pe tables that needed to be changed. Sounds like it may be time for ya to start burnin' your own chips! It's not that hard, and is kinda addicting....
[Modified by drive it, 12:30 AM 1/25/2002]
Oh yea-saw you've got a SR; it shouldn't be near as bad as a miniram, but the tip in bog-there's a couple of tables that miniram owners have had success with- I beleive it was the pump shot vs. diff. tps and the tps theshold for pe tables that needed to be changed. Sounds like it may be time for ya to start burnin' your own chips! It's not that hard, and is kinda addicting....
[Modified by drive it, 12:30 AM 1/25/2002]
Team Owner
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From: SE NY
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Re: Auto Xray results....help (AS84)
The reason for the paper clip is to get the IAC pintel extended when you turn the key to On. Once you unplug the IAC, you can remove the paper clip and start the engine.