need some help car is acting funny

[turbotrix2004]

well took the car out for a ride and now there is a slight stumble when i am off the throttle and then begin to accelerate... almost like a miss or pause? any ideas?

 

[whitehot1]

Do you have a scanmaster? if you do post some numbers with the car in park and at normal operating temp.

Could be something simple that needs cleaned and or adjusted but then again with these cars who knows.

How old are your plugs?

 

[turbotrix2004]

Tps 0.45
Spark advance 37
Mat 103
Iac 20
Esc counter 4
Rpm 975
Blm 128
Exhaust O2 lean

 

[turbotrix2004]

I don't have a scan master but used a code reader that also show live data

 

[whitehot1]

Are these the numbers you normally see? Have you noticed any changes to them?

Have you changed where you buy your gas? just trying to see if anything has been done from when it was running good before this problem started.

Since all we have to go on is the info you supply,so anything you can think of please post it just in case the question isn't asked.

How old is the 02 sensor and what brand is it? the bosch sensors don't work very well from my experiences,years ago it was a different story though.

I like the TPS set at .44 with the engine running at idle.

 

[turbotrix2004]

I just put in about 11 gallons of race fuel, and a new iac sensor.
I did notice that when I had the scanner hooked up and I reved the engine the o2 always showed lean. I don't know if it's bad? Last week when I did the same thing it would fluctuate from lean to rich

 

[TurboTom72]

Was the race gas leaded? Leaded gas kills O2 sensors. O2 should still be hunting from rich to lean.

 

[turbotrix2004]

Yes didn't know that lol that must be the issue then

 

[TurboTom72]

Yup, probably part of your issue. Change it. I have found Bosch units to work well for me. Are you running a stock MAF? Another common problem .

Tom

 

[turbotrix2004]

Yup, probably part of your issue. Change it. I have found Bosch units to work well for me. Are you running a stock MAF? Another common problem .

Tom

Yes I'm on the stock maf

 

[turbotrix2004]

So if I use race fuel I'll just continue to ruin o2's

 

[TurboTom72]

Yes, if it is leaded. They do sell unleaded race fuel like Turbo Blue. Octane rating isn't as high, but worked well for me before I went to alky. Make sure your MAF count is going to 255 at WOT. Also a tap test on the MAF can tell you if its going bad ( change in idle while tapping). I'd start with the O2 sensor swap first as that seems as a definite problem. You can hotwire your fuel pump by supplying 12v to the fuel pump test wire located behind the alternator. Remove the schrader valve on the fuel rail and attach a hose there to pump out the fuel. I have made the same mistake in the past. Dead O2 sensor and all. Get as much of the leaded fuel out as you can. Fortunately, the O2 sensors come with a 1 year warranty in the event you didn't get all the fuel out and mess up another one. HTH.

 

[earlbrown]

Denso's are the most lead resistant of the 02s. Might want to buy them 5 at a time if you're going to be running racefuel.

 

[turbotrix2004]

Ok guys thanks a lot for your help going to go pick up an o2 sensor now

 

[josh young]

Is it a stock O2 sensor or a heated one? If it's a stock one it probably wouldn't take much race gas at all to do it.

 

[turbotrix2004]

It's a stock o2. Also what are options for the maf??

 

[turbotrix2004]

Ok well I installed the o2 sensor stumble is not as bad but still there. I also noticed the idle doesn't come down right away.

 

[turbotrix2004]

Ok took it for a ride and little low end power. If I floor it from a stop it'll barley chirp / spin the tires in first and before it used to toast them

 

[pacecarta]

reset your ecm blms , unplug the orange wire by battery and then reconnect

 

[whitehot1]

Did you pull the spark plugs and check them?,they could have fouled from having a bad 02 sensor? What spark plugs are you using?