TPS question

[rb25drag]

Alright so I finally got my car out on the street yesterday and drove it to work 64 miles 1 way. Car ran AMAZING!! with a few exceptions.

First, when cruisen aprox 2500RPM's steady my wideband doesn't stay steady. Varies from 13.5-17.8, the car never has a mis and is extremely smooth, but looks like on the wideband it gets Rich sometimes and Lean at others.

second problem. Only when hot, 180 degree's when im coming to a stop light if im down shifting and dis engage the clutch the car will die, but if I just dis engage the clutch from 5th gear and coast it will stay running no problem, but it goes down to about 500-600 rpm and back up to 800-900 while setting at the light. Now it will only do this when at 180degrees or over 180 degrees, never when its from 100-165.

So my question is how do you set the TPS correctly? Im kinda thinking this is some of the problem.

when cold the car idles 1500+rpm and when Hot it idles 800-900 approx 15.0-15.6 % on the wideband reading.

Any Ideas? My timing is set at 20*, and FPR 45lbs No Vac.

[rb25drag]

Anyone?

[lilskyline240]

do you have the stock TPS sensor? or are you using a q45 one with a greddy plenum?

[mello88]

Wow 64 miles one way to work, that's horrible! I live 8 miles from my office and it still takes 20 minutes to get there with city driving, I can't imagine driving almost 140 miles a day to and from work... Your fuel costs must be thru the roof!

While cruising and idling the afrs should bounce around averaging at 14.7. It's just how the ECU works. I don't know if the range you put is normal though sounds like it runs pretty lean at times...

Dunno about the stalling, do you have a recirc'd or open BOV? Sounds like it could be an issue related to how the idle is set (and/or iacv fast idle valve). Have you done a boost/vac leak test lately?

PS Fuel pressure should be 43.5psi with the vac hose unhooked. Probably won't much much/if any difference, just thought I'd throw that out there.

[rb25drag]

Wow 64 miles one way to work, that's horrible! I live 8 miles from my office and it still takes 20 minutes to get there with city driving, I can't imagine driving almost 140 miles a day to and from work... Your fuel costs must be thru the roof!

While cruising and idling the afrs should bounce around averaging at 14.7. It's just how the ECU works. I don't know if the range you put is normal though sounds like it runs pretty lean at times...

Dunno about the stalling, do you have a recirc'd or open BOV? Sounds like it could be an issue related to how the idle is set (and/or iacv fast idle valve). Have you done a boost/vac leak test lately?

PS Fuel pressure should be 43.5psi with the vac hose unhooked. Probably won't much much/if any difference, just thought I'd throw that out there.

It is the Stock TPS.

Ya I spend a Ton of gas too and From work. Good thing is the RB Seemed to get around 24MPG.

My BOV is Recirculated.

When letting off the throttle I get the 22.2 reading on the wideband so I know its not loading up, It just seems to wanna Idle down too fast and nearly stall itself.

I did a boost leak test a week ago everything was good. I have always had this problem just never addressed it till now.

But its funny cause it only does it when the engine temps get up.

I have tried leaning it out on my AFC for idle but I get a mis.

[lilskyline240]

coming to a stop and it wants to die can be caused by an incorrect PCV setup. Do you still have the stock PCV installed and the hose from your vavle cover to your intake? If not you could be gettin unmetered air that is coming into your motor upon deceleration causing it to want to die. ran into that problem with my 300zx back in the day

[gawdzilla]

isnt stock timing on a 25 15 degrees? why are you running 5 advanced over stock?

the A/F fluxuation is normal under low load conditions. if you knew how a narrow band o2 worked that you would see why. it's called closed loop.

[rb25drag]

The PVC is the Stock setup. I haven't changed anything on the stock manifold.

Is there a specific way to set the TPS? Cause I have messed with mine before just by ear. I have it set to the best of my ear LOL, But Im sure there is a way to set it correctly.

[gawdzilla]

Is there a specific way to set the TPS? Cause I have messed with mine before just by ear. I have it set to the best of my ear LOL, But Im sure there is a way to set it correctly.

yes. should be ~.5V when the throttle is closed. use a multimeter and read the voltage and adjust it. you can do it with the engine off, ign on.

[rb25drag]

isnt stock timing on a 25 15 degrees? why are you running 5 advanced over stock?

the A/F fluxuation is normal under low load conditions. if you knew how a narrow band o2 worked that you would see why. it's called closed loop.

Stock timing is 15 degree's

Im running 20* because the car is not as sluggish and revs better/sounds better and drives better than on stock 15*. I have tried both ways and the 20* is best.

[rb25drag]

yes. should be ~.5V when the throttle is closed. use a multimeter and read the voltage and adjust it. you can do it with the engine off, ign on.

Which wire from which plug?

There is 2 plugs on the sensor.

[gawdzilla]

Which wire from which plug?

There is 2 plugs on the sensor.

i think its the one with the pig tail, not the one that plugs directly into the tps. that's the throttle switch iirc

[rb25drag]

Thanks, Ill out a volt meter on it this weekend.

[s13point5]

its the plug with the wires coming out of the side of the tps. like stated above, the plug that plugs directly to the end of the tps is the throttle switch. you turn the ignition on but dont start the car. probe the middle white wire

[rb25drag]

This is the sensor I adjusted:

I was assuming its the TPS but I could be wrong.

Here is a video of it revving and then dying:

Now again this is only after it warms all the way up. 180 degree's.

Any more Ideas?

[rb25drag]

anyone?

I have tried adjusting on my AFC, but nothing seems to be working.

The A/F readings when letting off the throttle read 22.2% which is right. and at idle its between 14.1-14.8%.

It just acts like it chokes itself for a min.

[lilskyline240]

why would airflow of 14% be wrong at idle/

[rb25drag]

14% as far as I know should be right. Nothing wrong with that.

It idles fine No problem what so ever. Its just when coming off a high Rev or down shifting to a red light it wants to die. Sometimes it cathes itself and others it just fludders out.

I also have my o2 sensor plugged up, Would this effect it?