1HOTZ

iTrader: (1)

I installed a set of ebay headers about 2 months ago, along with some bosch 13111's, sims on for the rears, and a custom true dual set up without cats. It was running great up till about two weeks ago, now when I get in it in the morning it starts up very slowly, almost sounds like the battery is drained. I am almost positive its not the battery though, it was just replaced last year. After it does get started it has trouble finding idle, it surges to about 1700 rpm's and drops to about 6 or 700. If I start driving it right away it usually warms up and its fine, but if I let it idle it nearly dies, and today it actually did die. I have noticed that this has started happening as the weather has been starting to get colder, on warmer days its usually not as bad. I am still running the stock tune, and im thinking it might be something with the a/f ratio. Any suggestions would be appreciated, thanks....

2001NBMZ28

I'd eliminate the battery/connections first - most parts stores will load test it free. I'm in Florida and on my third one at just over 24K.

1HOTZ

iTrader: (1)

I dont think its the battery though, that wouldnt cause the surging, or would it?

2001NBMZ28

Trouble finding idle/surging/hard starting - sure sounds like it could low voltage and it's maybe resetting the PCM. May not be your problem, but if you bought the battery last year and it fails the load test they should replace it free - most batteries have a 36 month free replacement guarantee. Bring it back to where you bought it and have them test it.

SSpdDmon

iTrader: (10)

Yeah, I agree with these guys. It shouldn't be tune related. It's either the Bosch O2's taking a dump or something else supporting the engine (like the battery). A pure bolt-on car should run absolutely fine on the stock tune. You might have a few positive fuel trims here and there. But, not enough to cause the symptoms you mentioned in your first post.

1HOTZ

iTrader: (1)

I had my battery and alternator tested, and they both passed. Any other ideas on what may be causing these problems?

TAQuickness

iTrader: (28)

Any chance you have a K&N recently installed or cleaned? Could be "gunk" on the MAF elements. Could be dirty enough to throw off the OL fueling, and not bad enough the O2's take care of it in CL

Somebody09

I hate the same problem after I installed [SLP] headers and it got cold. I put the stock manifolds back in and problems solved. Yeah, people told me it was the battery too. The headers and battery must be somehow related I think? I'm going to blame it on my exhaust being too cold for the O2s. And for those of you with headers who don't have this problem, what headers do you have? I'm willing to bed that the design (runners next/close to one another) helps more than you may think...

brad8266

iTrader: (23)

O2's have absolutely no function in open loop on cold startup and LTFT's are disabled until the car reaches operating temp. On a cold start it relys on VE/MAF for base fueling and then adds some extra fuel based on the OLFA table. O2 sensors are completely out of the picture during cold starts.

SSpdDmon

iTrader: (10)

Yeah I know...musta been one of them "blonde" moments back in September. But, you can have fuel trims before you reach operating temps. Hell, from the factory, CL operation starts at 92*F on the f-bodies. It's filtered a bit more while the ETC's are that low, but there are still fuel trims.

brad8266

iTrader: (23)

Yeah the LTFT's do turn on at low temp, but on the initial start when the engine is say 30-60F they are off.