Thread: Cold Issue

I have been battling this issue for awhile for now and I give up on trying to diagnose it.

When the car is cold it runs like crap, back fires through the intake at idle, try trying you cant go anywhere unless you rev to 4k rpms and then shift if before it'll bog like no other.

Once it warms up it runs fine, but I have been getting some backfiring issues. I have no idea what could be causing this, I've done a full tune up, messed with the timing, idle and nothing helps. Also just switched to a new 02 sensor still the same issue. The car runs like a champ when warm also perfect idle with cams at like 900 rpms.

Anyone have any idea what could be going on? I'm starting to think something is wrong with the engine. :/

I know you tried a different O2 sensor, but maybe it's the O2 sensor wiring harness? Sounds like an O2 sensor problem to me... =/

I'm useing the 4 wire one. A bad 02 sensor would cause it to back fire through the intake or popping?

Have you made sure the coolant temp sensors are okay?

last time i had datascan hooked up they were

Here's a video, at the end you can here the popping
http://www.youtube.com/watch?v=I2Gsw9aQt6Q

Any ideas guys?

I am pretty sure backfiring in the intake indicates a lean condition. Could the motor be running a little off once warmed up? Do you get lots of popping/backfire while coasting in gear after warm up?

VAC leaks are a good guess besides the O2, maybe coolant temp sensor is worth checking too.

Maybe time for Italian tune up or maybe just seafoam LOL

o2 sensors aren't used by the computer for feedback until it goes into closed loop. That's not your problem.

check the CTS because it runs the cold-start program on the board and controls the fuel-enrichment.

There still is the possibility of a maf issue as well.

^ That's interesting, Coheed at what temp does the OBD2 kick into closed loop?