Rough Idle

[iwantatta]

I just got a new TTA a few weeks ago and am going to take it to get smogged. Everything is stock except for the inlet pipe and K&N filter. However, i am starting to suspect that it does not have the stock chip.

It is running a little rough at idle.

I hooked up the scanmaster and got these readings after warmed up and idling:

02 - readings all over the place 200mv-600mv

AF - 6
L8 44-46
bat 13.7
int 125-132
bl 122
clt 182
ats 109
tps .48
iac 32

It also looks like it initially starts in open loop and then goes to closed loop after warming up. Shoudn't it stay open loop while idling?

I am going to see if i can found out where the chip is located and see what i got.

Any help would be greatly appreciated.

 

[Sweet6]

I would consider cleaning the fuel injectors.

 

[iwantatta]

Just found out the chip.

APXB 3897.

Is this the stock chip? I believe it is because of the APXB designation.

I'll look to see how to clean the injectors. I had a neigbor/mechanic mention that he heard some clicking noises coming from the injectors.

He said to try putting some fuel injection cleaner in a tank of gas. Is that what you are talking about? Or are you talking about taking them out completely and cleaning them.

 

[Jan Larsson]

Yep that is the stock chip!

 

[Sweet6]

As far as cleaning the injectors, don't bother with the gas tank stuff. If you know someone with a kit to hook to the fuel rail, use that. Your mechanic buddy should know about that method, but if you have to pay full price to get them cleaned at a shop,you might just want to take them off the car and have them cleaned and flowed. Casper's on this board is one place that does it. There are a few more but I can't remember their names. I want to say Chuck Leeper does them too.

 

[iwantatta]

Thanks guys. Your fast with your responses.

I'll see if he has something to clean the fuel rails with like you mentioned.

I'm also replacing the spark plugs and wires right now. Car is coming up on 30,000 miles and has not been driven around a lot since 1997. Odometer reading back then was about 24000.

 

[iwantatta]

Anybody know the torque rating when putting on the spark plugs? Or do you tighten it just enough but not tight.

Thanks.

 

[SuperTTA]

Hi,
Another thing to adjust is your tps.
I like .42 at idle.
Like others said, that is the stock chip, if it hasn't been reflashed. And the stock TTA chip isn't the smoothest for idling.
The 02's are supposed to be all over the place. The car with the stock chip runs in closed loop once warm.
Some aftermarket chips run open loop at idle to help smooth the idle (ie thrasher)
Have fun.
James

 

[iwantatta]

Pulled all the spark plugs and the tip is a light brown. The threads have a good amount of oil on all the plugs.

I also noticed one of the plugs was cracked on the part that the spark plug wire boot goes on to.

 

[iwantatta]

When people say that the stock chip has a rough idle to it, is it a misfire? Just want to make sure there is no confusion.

Seems strange that a stock chip would have a misfire.

Tomorrow i'm gonna tackle the tps and iac settings.

I've replaced the wires and plugs. The exhaust gases improved a lot from this. I also noticed that the PCV valve does not seem to be sitting in perfectly. It's like the 90deg. hose fitting was cut short or something. The outer ridge of the PCV valve never fits snuggly.

 

[Sweet6]

No, it should not misfire. Just start off giving it a full tune up including cleaning the injectors either with the rail kit or take them off and have them cleaned and flowed. Then if it still runs rough look at other things. You might want to change the coil pack during your tuneup too. In fact, that is probably your misfire problem. Full Throttle has them for $70.

 

[iwantatta]

Would checking the resistance between posts indicate a bad coil? I am getting about 11.7k on all of them which is within spec.

 

[Sweet6]

I heard the best way to test them is with Caspers tester. I change out my coil pack every few years. My car always runs smoother with a new coil pack. You could do the coil last. But if you are uncertain of the history of the car, I would just change it out. It is not going to hurt anything. And the Capsers tester cost the same as a new coil.

 

[iwantatta]

I replaced the coil pack but now it seems that whenever its idling it never goes to closed loop according to the scanmaster. I've let the car sit for a while and it still never goes to closed loop (coolant temp is 190).

Previously it was going to closed loop within a few minutes.

Forget it. I had one of the spark plug wires crossed. It goes to closed loop now.

 

[iwantatta]

Is there a trick to getting the tps at wide open throttle position to be between 4.5 and 4.85 V?

It seems that once i get the idle at .42, adusting for WOT throws everything off.

Not sure how to do the balancing act. Once i get the setting at .42 i tighten the top screw and start tilting it up. It seems that this is the only way to increase the wot voltage. But it only maxes out to about 4.3 v before i can't move it anymore. By then it has messed up my idle setting.

Any suggestions?

 

[iwantatta]

After doing some searching on the forums it seems that tps > 3.8 at wide open throttle is good enough. Is this true? Its kind of confusing because gntype.org mentions it should be 4.5 and 4.85.