THANK YOU Tom Sessions! (erratic idle solved!)

[V10SpeedLuvr]

After weeks of battling awful erratic idle, it seems as though that I've found a cure! I talked to Tom Sessions this weekend and he said he had seen some 96' GTS's have a bad ground going to the TPS and suggested I reground the wire going to my TPS. I bought some splice connectors and ran a new wire from the ground wire on the TPS to a bolt on the LH throttle body. I drove the car and it was fine except it'd flare back up after some WOT bursts. I called Tom back and he suggested I ground the wire at the PCM, so I grounded it there too. After doing that ground, I disconnected the ground at the sensor b/c I thought one ground at the PCM was enough. WRONG! The problem came right back and was as bad as ever. I turned the car off and reconnected the ground at the sensor and presto no erratic idle! I drove the car for 30 mins or so today and the problem did flare back up once after I went WOT and shifted to neutral to roll up to a redlight (I could see the tach needle jumping as the car was rolling). But, as soon as I came to a complete stop, the idle was fine. I'm not gonna call this a 100% cure, but it certainly has made the car atleast 90% better! The car has also quit its "surging" that it was doing when I was at 40-50 mph when the car would buck/surge with me. I dont drive the car everyday, but I'll update every now and then for the next few weeks to let everyone know if the problem comes back or not. Thanks again Tom!!!

 

[plumcrazy]

ya always hear good stuff about tom, im glad it worked out for ya.

keep your fingers crossed

 

[02ViperTodd]

CONGRATS CHAD!!!

 

[V10SpeedLuvr]

CONGRATS CHAD!!!

Oops, I never returned your phone call did I? I'll call tomorrow. I would call now, but ya know, the MLB All-star game is on

 

[KWIK96]

Tom's the man. He did a lot of work on my 01

 

[98viperGTS]

Tom is awesome, he knows his stuff and is a really nice guy.

 

[slaughterj]

TPS? As in, TPS report? Or as in Tom P. Sessions?

 

[V10SpeedLuvr]

TPS=throttle position sensor

 

[SUN RA KAT]

I did the double ground this afternoon and my surging was still there afterwards, but at a much lesser level than before.

Thanks Chad for the info.

Thanks Tom Sessions for giving you the info.

 

[V10SpeedLuvr]

I did the double ground this afternoon and my surging was still there afterwards, but at a much lesser level than before.

Thanks Chad for the info.

Thanks Tom Sessions for giving you the info.

Kenny, I'll IM you, but if anyone else are having these same problems:

(After doing the double ground):

Resynch your throttle body cables. Then, disconnect the PCM overnight and when you wake up tomorrow, reconnect it. BEFORE you fire the car up, turn it to the "on" position and push the gas pedal to the floor a couple times so the TPS can learn the voltage at WOT. That may help clean up some more of the surging/erratic idle. I drove my car for 15 miles yesterday including a couple of WOT bursts and a lot of redlight stops and all was fine I know what a pain erratic idle is (not to mention embarrasing) and I'll be more than happy to help anyone fight it. If anyone needs any more help or details, feel free to PM me or give me a call on my cell. 478-972-1815.

p.s.--Keep in mind that my car is 99% stock and Kenny's Eakmobile is more like 10% stock, so its a lot more reasons that his idle/surging problem didnt clear up completely after regrounding the TPS. After Macedo retunes it for him in a couple weeks, I bet it'll get even better

 

[ViperJohn]

Chad,

Thanks for the information. Could you post some pics of the grounding you did to the TPS and the PCM.

When you synchronized your throttle bodies, did you set one so that it remained slightly opened when off the gas or are they both even?

 

[ViperJohn]

Damn, I just realized I hit 1000 posts!

 

[V10SpeedLuvr]

Chad,

Thanks for the information. Could you post some pics of the grounding you did to the TPS and the PCM.

When you synchronized your throttle bodies, did you set one so that it remained slightly opened when off the gas or are they both even?

I'll get some pics up either tonight or tomorrow. My t-bodies open at the same time. I still get some of the bucking Gen 1's do at low speeds, but even it seems better, so I think the faulty TPS groundwire was also partly to blame for that. The surging when I was at higher speeds (40-50mph) is gone along with the erratic idle

 

[Jack B]

You want the throttle body with the TPS to open before the the other side. This is the drivers side on a Gen2. This issue is more related to bucking at very slight throttle and high vacuum. The adjustment is very sensitive, you want the first throttle body to open ever so slightly before the otgher side.

 

[V10SpeedLuvr]

You want the throttle body with the TPS to open before the the other side. This is the drivers side on a Gen2. This issue is more related to bucking at very slight throttle and high vacuum. The adjustment is very sensitive, you want the first throttle body to open ever so slightly before the otgher side.

How do you adjust the throttle bodies on a Gen 1? I know how to synch them, but not adjust them if I wanted one side to open before the other. Should'nt synching them automatically adjust them to open at the correct time?

 

[SUN RA KAT]

I went Vipering last night and it's a welcome shock as to how much better it drives now - the improvement is even bigger than first thought in my first post after I got it done.

 

[ROCKET62]

And to think that I used to laugh at the ricers ground systems on ebay. Might be a worthy investment.

Ebay JDM Ground Circle

 

[ViperJohn]

Where are the pics Chad?????

 

[V10SpeedLuvr]

Wow, I totally forgot didn't I? Sorry. I'll try to get some tomorrow, but I can explain really easy. I used a splice connector and tapped into the ground wire at the TPS sensor and connected it to a screw attached to the LH side throttle body. I did the same thing at the PCM and ran the new wire to a bolt right beside the RH side sill.

 

[Marc Lublin]

I had surging and erratic idle since day one in my car. I never knew if it was due to my modifications or not. I modified the car when it was brand new. It didn't bother me too much at the time. A couple of months ago the car started throwing TPS malfunction codes intermittently. I had Chuck send me a TPS and WOW, the car never ran so smooth. No more surging and my idle is rock solid, well as solid as it can be with my cam. Bottom line is, the TPS was bad from day one out of the factory. Anyone experiencing these types of problems, or Chad if you want to try for a 100% cure, try a new TPS. It's not expensive and takes about a minute to install.

 

[thebigsnake]

Its a mystery to me why when I'm coasting to a red light in neutral, the idle 'll stay fast till the car comes to a stop. Then it comes down to 750rpm.
Does the engine somehow sense if the car is moving or is stopped? Its just a bit disconcerting on hot days with the temperature needle creeping up.

 

[ViperJohn]

Its a mystery to me why when I'm coasting to a red light in neutral, the idle 'll stay fast till the car comes to a stop. Then it comes down to 750rpm.
Does the engine somehow sense if the car is moving or is stopped? Its just a bit disconcerting on hot days with the temperature needle creeping up.

There is a speed sensor on your tranny. It sends the information to the PCM.

 

[V10SpeedLuvr]

Here's the pictures of my pre-liminary fix. I need to add the eye hook ends to the wires at the ground points (instead of just twisting the wires around the bolts) and Tom Sessions said the blue splice connectors have a habit of cutting through wires over a period of time and suggested soldering the wires together at the PCM and TPS. Oh yeah, and I have to detail the engine bay. All will be done before this weekend because I have a carshow on Saturday

 

[ViperJohn]

Thanks man!

 

[V10SpeedLuvr]

Its a mystery to me why when I'm coasting to a red light in neutral, the idle 'll stay fast till the car comes to a stop. Then it comes down to 750rpm.
Does the engine somehow sense if the car is moving or is stopped? Its just a bit disconcerting on hot days with the temperature needle creeping up.

When I went on my first testdrive after doing this fix, my idle was still erratic when I coasted to a redlight in neutral and fixed itself when I came to a complete stop. I drove the car some more and did some more coasting and it was fine. I've driven the car maybe 30 miles since I did this fix and that was the only time I saw the idle be erratic at any time. I'm driving to Atlanta saturday (100 miles-ish) and will really be interested to see how the idle does during/after a long drive. I'll report back. If the idle does screw up, my next step will be replacing the TPS sensor.

 

[V10SpeedLuvr]

Thanks man!

You are welcome sir If you want any more info, PM me or just give me a call. My cell ph. # is at the top of this thread somewhere.