3800 Im tired of trying to figure out whats wrong

[imported_GraFFix]

2 weeks ago my car died out on the highway...Try to hotwire the fuel pump resistor thingy...still wont start...I tow it home.

At home i find that I ended up pushing the pins in the fuse box...so the relay wouldnt even make a connection anymore. time to buy a new fuse box

Bought a new fuse box...put a new fuel pump resistor in...car started right up..YAY!?

The car runs but I still had the P0171 code and after about 30 seconds of idleing the idle would start jumping if i gave it some gas it would stay running..if i left it alone it would die.

I thought it was my O2 sensor...

Well I bought a new O2 yesterday...put it in. but I still get the crappy idle and something still isnt right.

I went out and did some Atap logs and noticed the following.

when i first start the car...this is just at Idle.

AF ratio is at 12.9
Long term fuel trims are pegged at 16.4% ALWAYS
Short term fuel trims are at 0%

As I let the car idle the AF starts climbing...O2 warming up? and normal?

Once the car gets somewhat warmed up the AF ratio hits 14.7
the second the AF ratios hits 14.7...the short term fuel trim starts climbing and dont stop untill it hits 20.3% this is when the car starts surging and the RPM's start bouncing.

right before it starts surging i see the following...

AF Ratio 14.7
LTFT 16.4 (never budges)
STFT 20.3

Like i said if i hit the gas it will stay running..if I leve the gas alone you can see in the logs that the RPM's bounce from 800 to 500 then back to 800 then to 400 then eventually it gets so low that the car dies. It will fire right back up, but after about 30 seconds or so will start surging again.

Now if i drive it..it drives fine unless I stop and idle (at a light) then it starts bouncing again..unless i 2 foot it and keep the rpms up. once i start driving again Its normal.

No misfires (i think i had 2 at idle..but none while driving)..no sputtering...

Now! I have another thing im worried about..heh

When it was ideling last night i noticed the exhaust was smokey..not like a burning oil type smoke more like a steam..it wasnt that cold for it to be like this.

I also have something in my exhaust..its rattleing and it is in my muffler. Now i dont know if a peice of metal or something fell into the pipe when my headers were being put on but i can only think of the negative that I might have a peice of piston in my exhaust.

I also have a TB spacer and was wondering if it could be leaking coolant into the motor that way. causing the bad idle and the supposed steam to come out of my exhaust.

I was going to take off the TB today and check that but i figured id ask to see if I could get any answers before i do anything else.

I have 2 logs... 1 at just idle and one driving but i only went up to 45mph cause i dont want to do any more damage if it is running crappy. The logs look identical...same AF Ratio, STFT, LTFT, no misfires (except for 2 at idle..none while driving), no codes...

I need to know if anyone has any ideas? And I also have another question about the Atap. What parameters should I be monitoring?

Right now i have it set to check:

vehicle speed
engine speed
current gear
AF Ratio
Knock
Timing advance
injector pulse width
O2 sensor (bank1)
LTFT (bank1)
STFT (bank1)
intake air temp
Mass air flow rate
throttle position
total misfire count


Any help is greatly appreciated. This is really aggrivating me cause I didnt have the car for 3 months cause of the Trans then i get it back and all this crap starts happening.

thanks for reading my long drawn out explaination..
Joe

Click to read more...

 

[horist]

sounds like maybe a vacuum leak? if it's bouncing between 400 and 800 RPM at idle it sounds like unmetered air is getting into the intake somehow? Just something to check...

Also check all the fuses in the fuse box... make sure nothing's blown
Make sure the wires for the O2 Sensor are clear of the headers

 

[imported_Ron Vogel]

From the hip it does sound a lot like it could be the spacer. Mostly since your LT's are pegged and the steam.

 

[rob]

I think those LTFT are maxed out...I'll check the GM W manual trouble tree for that particular DTC.....I want to say MAP or yes a possible vaccum leak...Hook up a vaccum gauge...or use starting fuid in the suspect area.

 

[rob]

There is alot of things that could be going on...A couple suggestions though

Check the PCM ground.

You seem to suspect the TB. Pull the plug and see if the problem clears.Your LTFT's are maxted out.

Did you remov the TB screen? Yes-replace NO-check for abstructions

Check fuel pressure....!!!!!!

Check crankase vaent system.

What are you injecter PW's?

 

[J.E.T.]

Sounds like multiple problems which you have already fix some parts.

If you want to check for a tb leak, you can remove the sc top plastic piece with the three vaccum connections. Unscrew the 2 screws (10mm) and pull it straight out. Peer inside and if you see liquid trails, then you have a tb leak. If it's black and carbon'd up, then it's probably ok. This will save you a little time instead of pulling out the tb.

LTFT 16.4 (never budges)
STFT 20.3

BTW, my readings are the same way with the EGR hose leak right now. So you might want to look in that avenue. But once the car gets moving, the O2 starts reading and my trims move.

J.E.T.
'97 Red GTP

 

[xttc2000]

log your IAC with the autotap vs the desired IAC.

ive seen a lot of IAC problems cause symptoms like you are having. if you rev it to 3500-4000 and suddenly drop off the throtle, does it die?

and before you replace any more sensors, test them to make sure they work.
with the o2, Tpin into the wiring harness/clip and get a voltage- it should bounce between 200-800, force it rich with propane or lean with a vac leak.

 

[Royalgtp]

My TB spacer caused all of my problems. Biggest pieces fo crap out there......get rid of it now....