Hey guys I'm kind of stumped right now so I'm looking for some advice. A few months ago I blew my motor so I had it shipped out to buschur for a full rebuild 2.3 stroker, built head, and gsc s2 cams. Just a few days ago I got the car back and took it to my tuner and told them to give it just a base tune so it would drive and idle normal for the 500 mile break in period. Now I've got the car back on the road but the driveability really sucks. When taking off from a stop or when in gear at low rpms under around 1800 it feels like the car has no power and will barely move when I give it gas. Also when in higher gears like 3rd or 4th when cruising the car bucks and surges in gear. Is this normal for aggressive cams like this or is there something else going on? Also the car just started throwing a code p0134 for the o2 sensor and the car is running super rich. For example when I start the car it idles normal around 14.5-15 afr but after driving and then coming to a stop it idles super rich around 12.5. I honestly have no idea what is going on and if you guys could give me any advice that'd be great. Thanks in advance.

 

Yup this is normal for aggressive cams. You need a tune asap. When you start the car it seems fine bc you are in open loop. When you drive for a bit and the car warms up and you go to closed loop you will experience all these things you describe and the car will run rich since the ecu is dumping fuel for the duration of the cams. A tune will straighten all this out. Also you will lose bottom end with the cams so that should be expected. Does the car want to stall on you at stop lights?

 

That's not normal.

Maybe what ronaldo is saying that that is normal if you haven't tuned it yet. When I do a base tune I make sure the idle and cruise are hitting the AFR's I want for the 500 mile break in.

Is this on MAF or SD?

 

+1

 

Op stated he had his car back on the road so it's tuned with basic tune.

 

True. So the basic tune is not tuned, which goes back to the base tune needs to be tuned so he can do the 500 mile break in.

The base tune is just idle and cruise. It shouldn't be driving like he mentioned. It sounds like it's a base ROM and is not tuned at all or very little.

 

The car should not be acting like that. If your tuner can't do a drivable break in rom, do you really want him tuning WOT?

 

Its on a speed density tune. Also I'm kind of concerned because the tuner told me that he only did a base tune for the break in but when I picked up the car he gave me a dyno sheet. Is it really a good idea to put a car that's breaking in a new engine on a dyno? I really don't know what I should do right now I just spent $900 on this speed density install and tune and now my car runs like ****.

 

One more question would it be ok to keep driving the car like this until the break in is over I only have 400 miles left or should I get it tuned somewhere else for the base tune before breaking it in? I mean last thing I want to do is damage the motor during the break in.

 

Personally I would contact another tuner. Or do an e-tune there's a lot of amazing e-tuners on here. But that's just what I would do I never had any drivability issues on my s2s and like pure driven said a base map for break in is for idle, driving around to get your break in miles. So it should be able to drive just fine.

 

S2s on SD will drive flawless, what you are describing is something else entirely. Since you have a built motor it is inherently more noisy which the factory knock settings will allow to be interpreted as knock in some cases and make the car feel erratic. This isnt a cam issue but more a combination of many factors all playing at once. A more or less untuned SD tune is not very drivable but shouldnt hurt the motor as long as you are out of boost.

 

You should not even ask this question.

 

If you spent 900 already you should go back to the same tuner and let him fix what needs to be fixed.i don't understand how he could give you your car back without testing it and making sure it's good to drive for break in.good luck sir.

 

Alright guys thanks a lot for your help I've got one last question though. Just today I noticed that in 3rd gear when letting off the gas the car makes a pretty loud buzzing noise. It almost sounds like something is vibrating but its really loud. It doesn't happen all the time only sometimes but mostly in third. Maybe I'm just being overly concerned but I just spent a lot of money on this engine and want to make sure everything is ok.

 

Check to see if anything in the exhaust system is touching other components.