No power after warmed up

[BuickTV6]

This is a weird problem that ive been experiencing for awhile. When i first crank my ar in the morning, runs fine, pulls like a mother#$%^er. If i touch the gas and brake and let the turbo build some boost, she roasts the tires, and chirps into 2nd & third with ease. after 10 mins of driving after she's warmed up, that all goes away
It still has power, but does not feel as strong, and hesitates very bad. If i floor it off the line it stalls, or chuggs along until it his over 1500 rpm's. It takes about 4 to 5 secs for the rear tires to start turning when holding the brake and the gast at the same time.. It idols rough in closed loop, and only smooths out if I turn the A/C on. Its like a totally different car when it warms up and goes into closed loop. I've tried different ECM's, chips's MAF's and tps's, does the exact same thing in every instance. I am kinda lost here as to why it is doing this. It seems to run a lot better with the tps unplugged. Anyone have any idea here as to what is going wrong?


-Todders

 

[WFO]

sounds like it's too rich.what chips have you run?what do your o2's look like in closed loop?

too much fuel will make these cars run like crap .


new headers and downpipe should be a priority at this point.you've got some good parts,just need to finish up the combo and get it tuned.


later,sean

 

[YNOVATE]

i'm in the same boat buddy. Iv'e got the tools to get tuned I just need to get my transmission fluid problem fixed.

my car is running rich too....just ease the fuel back slowly untill your happy with how it runs. just monitor your boost too....too much boost with not enough fuel is bad...I've been down that road too. Luckily it was only the head gaskets that went

 

[FJM568]

Both of you guys...Check and make sure your coolant temperature sensor is hooked up...If it is, then your sensor is most likely bad...Replace it...It is the sensor that sits to the drivers side of the thermostat housing with the connector pointing straight up...

The other coolant temp thing that sits below the T-stat housing and points forward is the Coolant Temp switch...All it does is turn your dash light on when your car has already overheated(IDIOT Lights, ain't good for nothing, damage is done already!!!)...

Normally, when your car starts running like dog-sh*t, when all the other sensors are adjusted properly, it's usually the Coolant Temp sensor that is bad...Remember which one that was??? The one pointing up on the drivers side of the T-stat housing...REPLACE IT!!!...Another big clue that it's the Temp sensor, is that when it goes into closed loop, it's starts to run really rich...

While the car is in open-loop, it is running of set values programmed into the chip and is NOT using any input from certain sensors like the Coolant Temp sensor...When the car warms up and goes into closed-loop, then it uses the sensors as inputs to look up correction values and adjusts fueling, etc., based on those readings...

Clear as mud, right???

In closing, change that Coolant Temp sensor...See how it runs...

 

[WFO]

good thinking jim.the one i had said it was -40*.the car wouldn't even start unless you floored it to get into "clear flood" mode.

turbo-link to the rescue!.

 

[FJM568]

One other thing...If after you replace the coolant temp sensor and nothing changes, check the wiring for that sensor...You may have a wire that is grounding out...

There is a way to check the sensor with a Volt/Ohmeter...I need to make sure of something, before I say anymore, but it involves backprobing certain wires on the ecm wiring harness and checking that the reading you're getting is within spec...That way, with a new sensor in and if you're still not getting a correct reading at the ecm, then the problem would be in the wiring somewhere...

Hope this is helping...

 

[YNOVATE]

ok, another thing to check after I get the tranny situation figured out.

drivers side of the thermostat housing that points straight up. got it!

even though my car seems to run rich both cold and hot, I'll still check it out

thanks FJM

-Brad-