I just got my car running after a 2 year build. I was trying to run the motor for a while at idle to check for leaks, but the car is running all the way rich. the wideband is sitting at 10.0 the garage is quickly felling up with smoke and im not sure if its good to let the car idle like that till it gets hot. im not trying to figure out how to tune neither will I be driving the car. I just need to find out what window to go in the s300 to take some fuel out to get it to run a little better while I keep an eye out or leaks or any issues. the car was previously dyno tuned and it actually idles perfectly aside from the rich condition.

 

Wait, is this a freshly rebuilt motor?

 

yes

 

Do you not have a basemap for the new build?

 

You're blowing that rich, on a freshly rebuilt motor? RIP rings - they'll never properly seal now.

 

it cant be that far off the car was tuned using the same 1000cc injectors, same map sensor that are on it now. the only difference is a smaller turbo, motor is rebuilt using the same pistons obviously new rings, and bearings, but u think letting it run for a couple minutes can really cause damage.

 

If the only thing that's changed is the turbo then the tune shouldn't be off, turbo doesn't mean **** at idle.

you have a bigger issue.

 

ohh boy this is not what I wanted to hear.

 

maybe its my new fuel filter vs old its flowing more? i started the car with an open DP, it was tuned with a 3'' exhaust could that have played a roll. either way ill get it towed to my tuner and we will see what happens,

 

Am I correct in assuming you honed the engine before installing the new rings? On a fresh engine rebuild like that, you absolutely must follow proper break-in procedure. Sitting there and letting it smoke is basically the exact opposite of proper break-in. You're washing out the cylinder walls, making the rings seat improperly. You only have ~50 miles to properly break in a fresh motor, and you've already wasted most of that running time letting it idle and smoke.

I'm not saying it's blown by the strictest definition, it's just never going to perform optimally.

 

the motor was cleaned, honed, crank balanced, polished, resurfaced. i did my homework on everything. im honestly not really worried it did smoke but it wasn't like pouring out smoke you couldn't see, smelled like **** but i have seen a lot worse on base maps. plus I did exactly what I was supposed to do turn that bitch off once i saw something wasn't right

 

Fresh break-in oil, idle motor to temp. Fresh BI oil again, dog motor for 50 miles (best done on track or dyno). Fresh BI oil one last time, drive normally to 500. Standard intervals and your choice of oil from there.

Your word choice makes it sound like you let it sit there at operating temperature, which negates the first 50 miles if done for too long. You use the warm-up period to check for leaks and burns. After that, it becomes hard break-in time.

 

What MAP value are you idling at?

This didn't hurt your engine. Don't let people fool you into believing that running a short period of time like this will keep the rings from sealing.

Did you "record" your initial startup like you should have been doing?

 

I didn't log anything, but you got me looing at the MAP sensor and I found a leak in the vacuum hose going to it. I replaced the hose and everything is back on point. thank you

 

Don't understand how people miss things like this if they actually have stuck their head under the hood. That kind of vac leak should've sounded like a nest of snakes.

 

I always advise having the laptop connected for first starts so everything can be monitored immediately. Doing this, you would have immediately seen the map sensor sending erroneous data.

The engine will behave the same way when you have a faulty or inop map sensor as it will default to atmospheric pressure or even read positive pressure which is a heavily fueled condition vs standard idle fueling.