Tps

[Lofty]

Alright. Well as some of you know I was having some idle problems earlier.

So I put in a working isc, and my car works, well better.

Well now, I am getting idle surge, but this is the normal idle surge.
1200-1500 surge.
(As apposed to my old idle surge at 2000-2600 )

Messing with the Idle switch seems to help, but it's not properly adjusted right now.
The TPS is the thing thats worrying me, because I'm also getting bucking under 2000rpms.
So is this just the tps/idle switch out of whack? Or just the tps?

Thanks for your time, you guys are a big help.

 

[jrohner]

The first thing you need to do is turn your idle speed down by adjusting the BISS on top of the throttle body.

 

[Lofty]

The first thing you need to do is turn your idle speed down by adjusting the BISS on top of the throttle body.

It only really does this when it isn't heated up all the way, but it will do it when it's hot to, I normally idle at 750.

 

[4g64fiero]

Make sure you dont have any vacuum leaks behind the mas. I would also do a boost leak test( I know your car is n/t, but its easier to find vacuum leaks with a boost leak tester attached to the throttle body). Adjusting the biss is only a band aid. There is a vacuum leak somewhere for sure.

 

[brownfinger]

I, too have bucking right at and under 2000rpm. It's worst when it's cold, but it's still barely percievable once warmed up. With all the new parts and adjustments I've done, it may be more of a 'hesitation' now. I don't have any idle problems though.
I've adjusted the shit out of the TPS. While it helped the drivability, it didn't cure anything 100%.
You may have more than one issue going on.
I agree that there has to be some kind of vacuum leak for your car to idle that high. O-ring on ISC, or BISS, would pass air right around your throttle body.
If you do adjust the TPS, a tech at my local dealership said "488millivolts" And he kept muttering it like a drunken sailor. That's 2 mV less than the commonly quoted spec of .49-.52 V. 490mV is the lowest my TPS would go, but it did seem to help.
Use an analog volt meter to check it. If it's close to OK, and the needle swing is smooth, leave it be. It's such a huge PITA to reach the bottom screw, and I doubt it will fix your problem. Also, last time I did adjust my TPS I noticed something. My battery voltage was below 12V with the car not running, 13.8 V w/ the car running. This produced two different TPS voltages; adjust it with the car running if you can.

 

[dyno_detour]

Lofty, have you tried to adjust your throttle cable? Mine was doing the same thing. I re-adjusted the throttle cable and now it idles just fine. PM for some details.

 

[Lofty]

Lofty, have you tried to adjust your throttle cable? Mine was doing the same thing. I re-adjusted the throttle cable and now it idles just fine. PM for some details.

Yeah, I adjusted it. I removed my emissions equipment, and it made it better, I am leaking air, but I'm not sure where.

 

[mindset]

Good to see you've got somewhere Lofty.
Sorry I have no idea besides maybe vacuum lines.

 

[sirsol66]

Have you tried using soapy water on your vac lines to check for leaks? For me that's usually the easiest way of finding vac. line leaks.

 

[Lofty]

I have, but the sad thing is I couldn't even find the leak on the vac lines, and obviously they were bad if I pulled them and it made it better.

Okay, the 3 emissions ports on the top of my tb, I go to the right of that, and see a black gasket.
It looks torn up a bit, could this be causing it?

 

[DSMattitude]

I always look for leaks with a can of carb cleaner. leak will let cleaner in and richen the mixture, and idle smoother when your there. But the last time I was helping my friend look for a vacuum leak, it turned out the idle air control valve had gone belly up, so you might wanna check that out too.

 

[Lofty]

I always look for leaks with a can of carb cleaner. leak will let cleaner in and richen the mixture, and idle smoother when your there. But the last time I was helping my friend look for a vacuum leak, it turned out the idle air control valve had gone belly up, so you might wanna check that out too.

It's a new ISC, All the pins are 30 ohms straight.