Resolved [RESOLVED] 1G BISS Grounding

[mindset]

My idle has been really high lately. Yesterday, I did the VFAQ way of grounding out the ECU/Ignition Timing Adjustment plug, and then you're able to adjust the BISS. Ok, when I ground out the ITA Plug, the idle will drop down perfectly to 750, with the adjustments I did to the BISS. Then when I unground it, as vfaq explains, the idle will go back up to 1000. Do you guys think this is idle surge? Or am I doing something wrong? I don't think I can drive around with it grounded because the cap that you take of the ITA Plug is for waterproofing reasons.

 

[mindset]

if you are talking about the ips single green wire i just used a shielded female connector like this.

http://www.jamestowndistributors.com/userportal/woeimages/Electrical/54665.jpg

I can just get one of those at a hardware store right? Did you just splice in a new wire?

 

[steve]

I got a voltage of 11.5. That was taken with just the ignition on and NO ONE hitting the throttle. As stated above, the voltage increases as the throttle opens up more and more. Correct? So therefore my throttle cable might need to be adjusted? What do you think?
The wire looks pretty beat up. Its about to almost break. Can I just splice in a new wire? And get rid of the boot?

Are your talking about the voltage at the IPS?

"Using your DMM on volts measure the voltage at the male spade connector, with the green wire attached and the ignition on. With the throttle closed you should read something close to 0v and with the throttle slightly open 5v or more. (varies between 90 and later ECUs and I don't remember the specifics ATM)"

The voltage should be 0 with the throttle closed and in this case about 12v with it open. It sounds like your throttle body isn't grounded, or the IPS is bad, or the throttle isn't closing because the cable is too tight.

Does your throttle cable allow the throttle to close and have about 1mm of slack in the cable once the throttle butterfly is closed? If that's true it's adjusted correctly.

 

[ilco187]

I can just get one of those at a hardware store right? Did you just splice in a new wire?

that or a radio shack, yea i cut the old end off and back a little bit and extended it with a piece of new wire and crimped the connector on the wire then snapped right on the ips.

 

[mindset]

Are your talking about the voltage at the IPS?
Yes

"Using your DMM on volts measure the voltage at the male spade connector, with the green wire attached and the ignition on. With the throttle closed you should read something close to 0v and with the throttle slightly open 5v or more. (varies between 90 and later ECUs and I don't remember the specifics ATM)"

The voltage should be 0 with the throttle closed and in this case about 12v with it open. It sounds like your throttle body isn't grounded, or the IPS is bad, or the throttle isn't closing because the cable is too tight.

Does your throttle cable allow the throttle to close and have about 1mm of slack in the cable once the throttle butterfly is closed? If that's true it's adjusted correctly.

It looks like I'm replacing the female spade part. It just broke! Im going to go remove the intercooler pipes right now so I can look inside to see if its shut. I'll get back to you in a quick minute.

edit: Just had someone hit the gas while I looked for Voltage change. None at all. 11.5 throttle open or closed.
My cable seems fine. It almost seems as if my cable is too loose. I even "gently" pushed the throttle closed and it wouldnt budge and more, so it has to be closed disregard if I open up the TB and look inside, and my cable has some slack in it.
How do you know if the TB is grounded out or not?

 

[steve]

How do you know if the TB is grounded out or not?

See posts 4, 10, 15, 16 in this thread.
http://www.dsmtuners.com/threads/question-on-ips.318002/#post151694585
http://www.dsmtuners.com/threads/holy-ground-straps-batman-idle-problem-solved.155732/

 

[mindset]

I think we found our problem steve. Its not grounded out. Infact I'm missing the phillips screw that belongs there and the "strap" that grounds it out.
I'll have to go to the junkyard and find one. Thanks.

 

[mindset]

Hey do you know if this will officially solve my problem? Or do I just have to test and see if it does?

And can I just make a new bracket out of sheet metal? My friend has a ground strap that I can get measurements off of.

And steve, I really appreciate the time you took to help me out and all of the information you provided. It really helps get another DSM going on the road again. Thanks for everything.

 

[mindset]

Wow. Nothing changed. 2500RPM idle. I know I must've did something wrong. I think my car is missing something too. And is this (green) part what you're referring to as the "Ground Out"? I don't have that on my car. I made the bracket (red) and just bolted it from the screw on top to the throttle body bolt. If that is the part your referring to, where can I buy one? What does it bolt to after I attach it to the throttle body? I looked for places but couldn't find one.
<a href="http://tinypic.com" target="_blank"><img src="http://i44.tinypic.com/fef8eu.jpg" border="0" alt="Image and video hosting by TinyPic"></a>
<a href="http://tinypic.com" target="_blank"><img src="http://i40.tinypic.com/21323jq.jpg" border="0" alt="Image and video hosting by TinyPic"></a>
need2boostpsi engine bay pic credit.

 

[->PrOjEcTGS<-]

If you can't find the stock ground strap then you can always just use a piece of wire and two ring terminals.

Doesn't look the best... But it Works Great!!

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Edit... I know I'm missing a TB/E bolt. The threads are stripped out on the intake manifold and I'm just too lazy to get a helicoil for it. No leaks though...

 

[mindset]

If you can't find the stock ground strap then you can always just use a piece of wire and two ring terminals.

Doesn't look the best... But it Works Great!!

You must be logged in to view this image or video.

Thank you very much! I didn't think that would work because I thought there was a reasoning to why I need a thick piece of metal. I actually made a whole new bracket but it's not the best. I'll be trying the wire method ASAP!

What guage wire is that?

 

[mindset]

I have a million questions... and I need them answered!

Could a bad ECU cause high idle? I grounded the TB straight to the negative battery terminal. And I still have a 2500+RPM idle and it increases as I leave it on. So its either a bad ECU or a bad IPS.
I'm clueless now...

 

[talon187]

this may sound stupid but anyone got a pic of this grounding strap?

 

[steve]

Wow. Nothing changed. 2500RPM idle. I know I must've did something wrong. I think my car is missing something too. And is this (green) part what you're referring to as the "Ground Out"? I don't have that on my car. I made the bracket (red) and just bolted it from the screw on top to the throttle body bolt.

The green part you highlighted is the intake manifold stay. It a support for the intake manifold and lifting point for the engine.

Could a bad ECU cause high idle? I grounded the TB straight to the negative battery terminal. And I still have a 2500+RPM idle and it increases as I leave it on. So its either a bad ECU or a bad IPS.

I don't see you confirming that the test now works after you grounded the throttle body. I also don't see that you reset the BISS after fixing the IPS. I forget, have you also verified that the base timing is set?

this may sound stupid but anyone got a pic of this grounding strap?

Please read the thread. You'll find that your question was answered already.

 

[->PrOjEcTGS<-]

this may sound stupid but anyone got a pic of this grounding strap?

Found this in a reply from steve in another thread: (which steve already linked to in post #30 of this thread)

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[steve]

That's a 90 throttle body. Please read post #30 of this thread for other examples.

 

[->PrOjEcTGS<-]

That's a 90 throttle body. Please read post #30 of this thread for other examples.

Ok... The ground strap on a '91-up goes from the other upper bolt to the screw location in my picture.

 

[mindset]

Ok I reset the BISS. It's idling at 750.
Hopefully when I start it up later it will idle like it just did.
I will get back to you and let you know with another update.


...now my car doesn't want to go into 2nd gear. Just grinding. Awesome.

 

[Highbooost]

Holy crap I actually learned something new about a DSM. I had no clue that thing was a grounding strap, it makes sense now. I always thought it was to hold onto the t-body elbow. Man, this is the first thing I have learned about a 1g in a lonnnng time. Cool I guess I should put that thing back on, hmm wonder where it is.

Later Dr Turbo

 

[steve]

Ok I reset the BISS. It's idling at 750.
Hopefully when I start it up later it will idle like it just did.
I will get back to you and let you know with another update.

Well? Did we fix the idle/BISS adjustment problem?

 

[mindset]

Well? Did we fix the idle/BISS adjustment problem?

Yessir. I'll change it to resolved.

 

[ilco187]

the whole time i have been reading this thread i never knew that the t-body was not grounded/ upon reading this thread i found that i to am missing that strap and have horrible idle even dies on decel, but now i hope this will solve my problem.

 

[need2boostpsi]

need2boostpsi engine bay pic credit.

not my current engine bay, thank god

 

[->PrOjEcTGS<-]

the whole time i have been reading this thread i never knew that the t-body was not grounded/ upon reading this thread i found that i to am missing that strap and have horrible idle even dies on decel, but now i hope this will solve my problem.

It will... I had the same problem and when I wired up a ground strap the idle got better and my fuel injectors actually turn off on decel again. You'll probably get better gas mileage because of it too.

 

[1GTalonTSI]

Dang a lot of info to process... now I must apply it.