codylew

So my engine won't idle until the water temp is above 150 degrees. The guy I bought it from said it was missing some type of cyclinder type dealy? Anyone have any idea what this could possibly be or what is causing this?

RotaryRocket88

iTrader: (7)

The guy before you removed the thermowax, which boosts idle speed until the engine warms up.

codylew

how much would one of those run me and is it fairly easy to install?

djAngel

iTrader: (2)

I have the same problem but its going away little by little. starting after my rebuild. Let me know what you find out. I gotta hold the pedal for like 10 seconds before it idles .

Aaron Cake

iTrader: (1)

A thermowax should be easy to find in the classifieds section of this forum. Many people remove them, for some unknown reason, so I bet there are piles just sitting in people's garages.

codylew

Well, i don't think its the thermowax anymore...upon my inspection I have found that Im missing my accelerated warm up system solenoid valve.....would that be the problem?

RotaryRocket88

iTrader: (7)

You can do without the AWS valve. If the BAC and thermowax are still in place, you'll still get the 3k cold idle, which drops to 1.5k until warm.

codylew

damn, I seriously dont know what is causing this problem then. I can see the thermowax. Gosh, I hate when you think you found the solution.

codylew

btw I haven't been able to figure out what BAC means....it's probably totally obvious

midnightbluefc

iTrader: (19)

its an s4 na?

RotaryRocket88

iTrader: (7)

There's an abbreviations sticky thread that will help you out. BAC = Bypass Air Control valve. On an S4 NA, this will be connected to the dynamic chamber on the driver side. On all others, it will be connected to the UIM (Upper Intake Manifold) on the passenger side. It is a cylinder with a 2-wire connector and coolant lines running through it.

Testing the water temp sensor on the back of the water pump housing would also be useful. Use the FSM (Factory Service Manual) to test it and other devices at the ECU pins.

datz

i could be wrong but i thought the AWS creates the 3k idle at startup, so with it gone or unplugged why does it still do it. only thing i can think of, the extra air comes through the BAC?

codylew

no its an s5 turbo

codylew

I still have my BAC in there and the thermowax. I know that the previous owner installed a water temp gauge in the dash. Is it possible he somehow is connected the sensor or something in order to get this gauge to work?

RotaryRocket88

iTrader: (7)

The BAC and AWS solenoid combine to supply enough air to boost idle speed to ~3k RPM. It seems that the BAC does most of the work, as when the AWS is unplugged, you will still see idle speed jump to roughly the same RPM. When I did this on my S4 NA, it only changed by a few hundred RPM.

An aftermarket water temp gauge will almost certainly use its own temperature sender. I'm not sure what this has to do with your problem.

codylew

damn, Idk what would be causing the problem then. The only thing I can see that's missing is the AWS valve, so something must not be functioning right?

codylew

So the thermowax, and BAC are equipped, however, I jsut noticed that the charcoal canister is also missing in conjunction of the AWS. I have a charcoal canister that came with the care but I have no idea why it is off or if it is still any good.

lastphaseofthis

iTrader: (8)

maybe check your ECT like rocket said^ as with a faulty one your ecu think's the water is hot even when it is not. it defaults to like, i dunno 180*F? and wel duh, that will cause cold idling issues.

satch

iTrader: (1)

Just because you have the thermowax it is not a given that it is functioning properly. The FSM explains how it should work and how to tell if it needs an adjustment.

codylew

so the charcoal canister wouldn't cause it either or should i try and find the ECU and test the connections with a test light?

satch

iTrader: (1)

The canister is for emissions. You still need to verify that the thermowax is operating properly and if so you cross it off of the list of possible causes for your quandry and move on to other items.

codylew

I dont have a factory service manual, I have a Haynes manual but it doesn't go indepthon how to check my thermowax to make sure its working properly

satch

iTrader: (1)

Click on the 89 FSM and look in the emissions section.


http://foxed.ca/foxed/index.php?page...nual#secondgen

Also look at post #79 and thereafter in the link below.

https://www.rx7club.com/showthread.p...dle+cam&page=4

codylew

thanks when I get a day off Ill check it out and see what I can do. and if it works