Sputter on warm start ups

[Michael30815]

Car starts up fine when it cold and drives fine. But whenever I stop at the store after engine is warm, when I crank it back up and drive, it sputter like its flood with gas or something. O2 aren't going above 500"s when warm. Thinking it may be O2 sensor?

 

[GNONYX]

It's a possibility the O2 sensor, maybe you can also post the ScanMaster # after engine is warm up.

 

[aminga]

Car starts up fine when it cold and drives fine. But whenever I stop at the store after engine is warm, when I crank it back up and drive, it sputter like its flood with gas or something. O2 aren't going above 500"s when warm. Thinking it may be O2 sensor?

Cross Counts?

 

[Michael30815]

What are cross counts?

 

[aminga]

What are cross counts?

what are your O2 crosscounts when the car is warmed in closed loop?

 

[Michael30815]

500"s to 300"s

 

[aminga]

500"s to 300"s

Thats are the O2 sensor volts. Crosscounts are always in the range of 0-255

 

[Michael30815]

Where do I find that info on scanmaster?

 

[aminga]

Where do I find that info on scanmaster?

It's parameter marked CC. It should basically count from 0-255 in about 30 seconds or so. If it's not counting up or counting up slowly then the sensor is bad

http://www.vortexbuicks-etc.com/basics.htm#O2 sensor voltages for tuning wot performance

 

[earlbrown]

^the bigger the jump, the better.

 

[Michael30815]

Going to check tommorow

 

[Bescurred]

What kind of Fuel Pressure Regulator do you have?

 

[Michael30815]

Ok, I have did a lot of change today, first off, I installed my 4 inch MaF today. Also I check the CC perimeter like you ask, it jumps 5 to 12 closed loop all the way to 255. Fuel pressure is set when car is cold at 42 vac off and 40 with the Vac on.

 

[Michael30815]

Going to drive tommorow to see if MAF make a difference when starting it back up which it probably won't.

 

[Bescurred]

Brake fluid is low btw...

 

[Michael30815]

Thanks, will check on that tomorrow as well.