crcleofdst

After coolant seal failure last September, I managed to wrap up my rebuild last night, and fire the car up.

Mods existing prior to rebuild:

sbc id boost controller
oil & water temp gauges
oil & fuel pressure gauges
boost gauge
rb duals
rx7 store downpipe

Mods installed/done during rebuild:

Med. streetport (done by yours truly with templates from pineapple)
ss omp lines
pfc w /datalogit
1300cc secondary's (cleaned and flow tested primary's)
PLX sm-afr wideband 02
ACT prolite flywheel
ACT street/strip clutch (new pilot and throwout bearings)
metal ast (forget which forum member I bought it from)
Banzai oil pan brace
efini y pipe
ported wastegate

I replaced every rubber hose (except airbox hoses), the FPD, all check valves, and the atkins rebuild kit provided me with all hard and soft seals.

I was pretty nervous when I went to start the engine. I followed the steps for startup (build oil pressure, install plugs, prime fuel system), and it fired right up on the first try. Heres the problem: I am getting an awful screeching noise, and some smoke after a few minutes from the area of the secondary turbo during idle. Now the turbos were ok prior to the coolant seal failure (making no noise at idle, and boosting fine), but they did sit on the shelf untouched for quite a while.

If I were to guess at the problem, I would assume that the turbo was not getting oil because of a blockage in the line. The only thing is, I thought that the exhaust was routed away from the secondary turbo (until close to changeover), meaning it shouldn't be spinning at idle. Am I wrong here?

I should mention that my oil pressure is 110psi at startup, and settles to around 50-60psi at 2k rpm (which is where it is idling at this point).

Rx72Heaven

iTrader: (2)

Do ya have the Vac hose connected to the actuator on the Y pipe to close the butterfly so no air pressure gets over to the secondary turbo?

crcleofdst

Vac hose is connected, and I verified that the butterfly was working prior to installation, but I don't think that would have an effect on the turbo spooling at idle.


I guess I could remove the secondary inlet pipe and see if the turbo spins freely, but I think I just need to pull the turbos and check the oil/coolant lines. (which I really don't want to do now that everything is back together). I have a spare set of turbos with a good secondary that I can Frankenstein together if necessary.

At the end of the day, I guess I should be happy that the motor fired up, and sounds good otherwise.

kf3er

iTrader: (1)

Do you hear the screaching noise during idle or only when you give it some revs? Did you do anything to the AVC in the UIM?

crcleofdst

Both at idle and revved, and it does seem to increase in speed with revs. Everything was left intact in the rats nest (I did not remove anything emissions related or otherwise).

Mahjik

iTrader: (1)

Can you get a video with the noise?

crcleofdst

I will post a video soon.

crcleofdst

Just doing some reading (found kf3er's AVC thread), and I have a feeling this may be the ACV. If I quickly blip the throttle to bring the rpms to around 3k, the noise goes away for a split second. I had disconnected the wideband 02 sensor plug during the install, and forgotten about it. I found the connector (partially melted) laying on the downpipe, aft of the 02 sensor, so I think I found the source of my smoke as well.

I did not touch the ACV during the rebuild, but I am sure that the LIM got banged around a little sitting in a bin for 4 months.

crcleofdst

Ok gurus, I have replaced the ACV gasket and wagon wheel, and had the UIM off 3 times to check the stupid wagon wheel. No matter what I do, I am still getting this damn noise.

Short video here: http://www.youtube.com/watch?v=ojIotw7XvSM

So now I am wondering if the ACV is broken, or if I am missing something else. I saw nothing wrong with the old gasket or wagon wheel when I removed them, and the new pieces seem to be fitting as they should.


^^ This makes me think that I missed a "pill" when I replaced all of my vac hoses. Could this be the issue?

Rx72Heaven

iTrader: (2)

To me sounds like the UIM isnt tightened down all the way, give those bolts another torque.

crcleofdst

The video doesn't do the sound justice. It doesn't help that I am too cheap to buy a "real" video camera.

I am 99.9% sure that this is noise from the acv valve. It chirps randomly at idle, and under throttle the chirp turns into a full on screech. The screech disappears completely at right around 3k and above, and promptly returns when rpms fall back down.


Unless this noise can come from complete failure of the acv valve, improperly routed vacuum hoses, or even the harness connected wrong, I can only assume that I installed the "wagon wheel wrong".

I guess I will pull off the UIM tomorrow, and try again.

crcleofdst

Just to close this thread out, the sound was coming from the bottom air pump pipe where it connects to the LIM. It seems that I had forgotten to tighten one of the bolts.