Chewbaccsw5

So I am taking my engine to get rebuilt because we found out the rear rotor was blown by the PO. He did a lot of splicing and electrical work that has me a bit worried and Im wondering if it would be best for me to starting looking around here for a wiring harness that I can equip when I put the engine back in. The current harness is all electric taped up and just has be concerned haha

RotaryRocket88

iTrader: (7)

Do you know the reason why the engine blew? Any reason you might think it could be related to a sketchy harness?

Chewbaccsw5

That is my fear, the PO wasn't very smart or mechanically inclined so I have no clue why caused it to blow. This is a reason why I wanted to get a new harness. I need to ask the Doc that is rebuilding it where a few things go; there are a things unhooked and unplugged, filled with screws and BS....very sketchy...

RotaryRocket88

iTrader: (7)

If it's in poor shape, a replacement wouldn't hurt.

I browsed your previous threads, and saw you're talking about an S5 TII. In future threads be sure to include as much relevant info as possible. The most common reason for a stock-turbo TII engine to blow is going lean due to too much boost & too little fuel. It would be in your best interest to find out what injectors, fuel pump, ECU and any potential add-ons like an FCD or SAFC are being using.

But there are other causes too. An improperly set CAS can advance timing and blow an engine. A wiring problem could be a possibility too if it's fuel/timing related.

Chewbaccsw5

Yeah that is my worry. Im gunna have to tune it when I get my engine back in 2-3 weeks and my mechanic believes it could be a boost problem but he is gunna crack it open and see next week.

Chewbaccsw5

1) if I post pictures of the harness could someone tell me if it is worth putting back in based on how tampered it looks; I will include areas that I have in question.
2) Anyone have a picture of a cold start? I am afraid the cold start is removed which would definitely be the cause of the problem that requires me to have to hold the gas until it warms up for a while. I would greatly appreciate it

RotaryRocket88

iTrader: (7)

1) maybe

2) What's a "cold start"? Do you mean thermowax, Accelerated warm up solenoid, or BAC?

Chewbaccsw5

Im guessing this is the same, the wording from the book calls it the "sub-zero starting system.... Idk I described the symptoms to my rotary mechanic, which they are it doesn't idle on its own unless the water temp is atleast 130 degrees F, and he said it sounded like they removed the "cold start". I asked before on these forums if it not having the accelerated warm up solenoid would cause that and someone told me no that wouldn't be the cause of the issue. I am almost certain this solenoid is missing, the last time I looked.

RotaryRocket88

iTrader: (7)

The sub-zero starting system was recalled back in '89 or so. It was a valve on the intake manifold that would inject coolant into the intake if temps were below freezing. It never worked.

The thermowax is the primary assist for cold starts. It boost idle speed to 1500 RPM until the engine warms up fully. The BAC and AWS solenoid team up to boost idle speed to 3000 RPM for ~17 seconds on startup, but this is to warm the pre-cat(s) for emissions purposes. If you remove one of them, the other will still direct enough air in to reach almost the same RPM as with both.

Chewbaccsw5

Ok, well I know on the upper manifold I have come across the BAC screw, I believe the solenoid is off too, but where exactly is the thermowax? Do you think it malfuntioning could be my problem, as if it is just worn out?

RotaryRocket88

iTrader: (7)

What is the problem?

The thermowax is on the back side of the TB. It'll have coolant lines going in/out. It either works or it doesn't. Idle should sit at ~1500 RPM cold, and gradually drop to ~750 RPM as the engine warms.

Chewbaccsw5

Rear rotor blew out, Im getting it fixed as we speak. Im afraid that the wiring harness's tamperings may have something to do with why it blew, like the ECU got jacked up or timing was all off. That is why I made this thread, but I also have other problems, the next main one being that the car doesn't idle on its own until water temp is about 130 degrees F.
So Im thinking maybe my thermowax is shot.

RotaryRocket88

iTrader: (7)

Well, I gathered that the engine blew, and that would clearly be unrelated to idle control systems.

A temperature related idle problem could be related to the water temp sensor, which is on the back of the water pump housing. You can check for trouble codes, or test the sensor output at the ECU: http://www.johnr.com/cpucodes.html.

Chewbaccsw5

K, Ill check it out. Basically I changed topics through the thread which is why the idle problem was brought to attention