OK, finally got my motor firing up. It runs pretty smooth at 2500 rpm, but won't idle. I see from searching that this is common for rebuilds with used rotor housings like mine. I think their might be another problem though due to the way it dies...

I was wondering if any of you that have experience with this could help me see if my engine is normal or not.

The thing that makes me think it is something else (besides fresh seals) is when the idle gets low enough to die and I hit the gas, it kind if stumbles before it dies. I would think it wouldn't studder like that, but I'm not too sure.

 

is it ported? i know that my streetported turbo wont idle until it is completly warmed up.

 

is it astock motor?? what have you done to the engine??

 

Nah, it's supposed to be stock. Upgraded to 720 secondaries, but I thought they don't turn on until there is some boost.

 

is it t2 or na??

 

s5 t2.
RA apex seals (yeah, I know)

 

have you check tps or the bac valve?? or timing?? what about any exhaust leaks??

 

Cleaned out the BAC valve today. That didn't change anything.

No exhaust leaks. Haven't checked for vacuum leaks, but I listened and didn't hear anything. Timing, I haven't looked at yet, I thought it had to idle first. TPS i'd save to last cause thats the biggest pain.

I'm more looking for what a fresh motor will do with regards to low compression and all that stuff. People say they die, but I want to see how they die haha.

 

well, fresh rebuilds sometimes need to build compression before they idle correctly...

just drive it...

 

yeah, thats my plan for tomorrow. I'm just trying to see everything.

 

hmm..that said just drive it then lol

 

Make sure you didn't stab the timing incorrectly. But yeah... new rebuilds will take a few miles of driving under load to seat the seals properly... and another couple hundred to break them in fully... probably 1000 or so until you can womp on it.

 

argh, found a problem. A pretty big chunk of the MAF sensor was busted in. My friend is trying to fix it now with his awesome model building skills. I hope he gets it, cause I don't see too many for sale in the FS section.

 

The S5 MAF is a little rare, but just so you know a fresh rebuild will likely not idle very well. In fact, you shouldn't run it over 5000rpm until after 1000 miles, and around that time is when it's going to start idling well.

 

Why are most of you saying a fresh rebuild won't idle. He was saying the car dies below 2500. A fresh rebuild will have a rough idle, or even a changing idle but not die below 2500. And whoever said a streetported car won't idle until it's warmed up needs to do some tuning.

 

OK, the situation now. . .
It runs a lot better after fixing the water thermo sensor. It still doesn't idle but I can manipulate the throttle under 1500 and still save the engine from dieing. The MAF looks fixed, but I had to let the epoxy set up, so I'll see on monday. It was definitley a nickle sized hole after the MAF though, that would cause some pretty bad running right?

 

yup, that would cause some horrible running. my na didn't idle well after rebuild either, but after being broken in after about 1000 kms, it now idles great

 

Success! Fixed the massive vacuum leak and now it idles like a champ. Pulls nice vacuum too. Remember, starting fluid is our friend haha.