will1380

Every since i put longtubes on my car it has been having trouble starting. Sometimes it will start right up but other times it takes a few tries to get it to start. The car is also down on power after the header install. I raced my dads stock a4 Camaro and lost by about two cars so i know its not where it should be power wise. Is a tune what i need to get my car running right again?

RamAir95TA

iTrader: (2)

I would immediately suspect burned plug wires due to the headers. Headers alone will not make your car slower. A tune will help, but will not fix an already poor running car.

Are they ceramic coated? Some ceramic coatings can foul out O2s when it burns up for the first time.

will1380

They are ceramic coated. I've replaced the wires and 02's already and still no luck. I paid alot of attention in wrapping the headers with header wrap to make sure they weren't going to burn any wires.

gregrob

iTrader: (8)

You probably got a plug wire crossed up. Double triple quadruple check that the wires match the firing order...

will1380

I just spent an hour double,triple,quadruple checking all the wires and they all matched up to the firing order. Also checked again while i was under the hood and mad sure no wires were burnt.

5_LTR_ETR

recheck if all your plugs got completly tightened on reinstallation. i managed to miss 2 of mine

02v8ta

iTrader: (8)

Not to hijack but really? Getting some installed soon is why i'm asking. Sooo after the first few cycles it'll either foul the 02s or not, is it common?

moehorsepower

iTrader: (3)

All cars no matter the same, react different, A local muffler shop had a stock LT1 and installed headders and ran slower until I had to do a tune, When we had the shop I would see headder installs cause lean A/F and some to go to the Rich side and some run better without any tuning, so if all checks out ok, You probably need a tune, Maybe have some one scan it first before you invest to see what its doing.

will1380

Could bad injectors be causing the problems I'm having? Car has 142k on it and still has the factory injectors on it.

moehorsepower

iTrader: (3)

Well if the car was running fine before then unlikely its the injectors..

nighthawk15

Did you use cut to fit wires? If you did, did you make absolutely sure all of your connections were good? Also, sometimes the stock module if not tuned or replaced with an LT4 module can pick up false knock from headers or a loud exhaust and screw with the timing, but that still shouldn't give you problems starting the car.

will1380

I have another question. I'm going to go ahead and replace the injectors since they have 142k miles on them. I was wondering if this set of injectors is what i need and will fit my lt1 engine.

http://cgi.ebay.com/ebaymotors/24-LB...Q5fAccessories

RedHotG8

iTrader: (1)

To get the most power out of the headers you need a tune, which will definitely make your car run better.

transbird95

iTrader: (4)

I wouldn't worry about the injectors man. If it was working fine before I doubt it's the injectors and 145k isn't all that bad. I would scan it first and see if it's picking up knock and see if there is any codes first. If you can't find anything that you think you could have done wrong check the fuel pressure.

MavsFORMULA

iTrader: (4)

I replaced mine on my last LT with 150k due to a fueling problem, which i should've known in the first place was the fuel pump. The injectors were perfect and are now in my buddies heads and cam mustang. The car shouldn't need a tune but it also will help. Check your fuel pressure.. Any engine codes?

BigD383lt1

Did you have to extend the harness for your o2 sensors if so did you do it equally? If you change the injectors unless going with the stock size you will defiantly need a tune and if your going to change injectors you should go up in size if you plan on doing any mods in the future. I don't think it is needed at this time I've seen guy's run for 200k with stock injectors. I would look elsewhere the odds of it being injectors are slim.

ZFreie

160k on my stock injectors. Still runs great!

FormulaJoe

iTrader: (5)

Do you need to have them both the same extension?