Hi,

I just recently removed and replaced my radiator. I initially filled with coolant and began the burping process.

Initial start up was exactly as it was before, AF of high 12's low 13's.

Everything was looking great, radiator fans eventually switched on perfectly.

Then when it seemed the thermostat opened, AF dropped to low 10's and needless to say car started running horrible! It can't stay at idle.

Only thing I can think of is when water hit the coolant temp sensor it must of malfunctioned but the temp reading on the Power FC looked right on.

Any ideas?

 

let it cool down and recheck the coolant level, if it dropped enough then the water thermosensor will be fluctuating to an overly cool temp reading which will affect your AFRs drastically.

no matter how well you think you bled the system they always seem to still have an air pocket somewhere that takes 2-3 warmup cycles/topping off to get rid of.

 

From your comments, it does not seem like you have done any real trouble shooting of the problem. Make sure the radiator is really totally burped.

The water temp sensor for the PFC is metal and I doubt it failed.
Use the PFC Commander to check both air and water temps, and other functions.
If the temps and corresponding voltages are good, look elsewhere.

 

I let it cool down completely. Water level dropped from being in my water filler burping funnel to an inch or so below the fill cap.

Started it back up and same symptoms occurred. Checked water temperature and air temps which were all Inline with what they should be?

 

The radiator definitely needs to burped more. Problem is that the car literally won't run. I'm kinda stumped. Was running perfect, started perfect, then when fully warmed up everything changed. All of the temp values were where they should be when it first went nuts and when it was fully cooled which is why I can't see how the tune could of changed.

If there was a huge air bubble would it effect the tune even if the water and air temps were normal?

 

start checking other random things like your map sensor line and for popped off vacuum hoses after the throttle body which will cause it to run rich due to low vacuum.

 

I definitely will. I did a quick look at vacum lines and sensor connections and didn't see anything. It's single turbo so there isn't as many vacum lines. I'll also use the datalogit to see if any other sensor values are off and report back. Just strange that this occurred right when the thermostat opened.

 

I hooked the laptop this morning to monitor sensor values with the datalogit software. When I started the car it actually held idle even though it was running horrible.

Looks like I might have a bad map sensor. Map Ref is in a spot that probably should be unreachable. PIM value is in a range that would imply the car is under boost. I triple checked for vacuum leaks and could not find any and the boost gauge shows a health negative PSI reading. I posted this on the RX7 datalogit yahoo group and haven't heard anything else that could indicate getting a map reading like this at idle other then vacuum leak, bad map sensor, or heavy resistance in the wiring for the map sensor. It just seems unlikely that the map sensor would go bad at that time.

If anyone has any other suggestions let me know. I'm going to install a GM 3 bar but would like to verify that the map sensor is the problem before doing so. Wish I had another stock sensor to try. A new one is almost $500 at the dealership.

Here are the sensor values a minute or so after start up.


Here are the sensor values about 10 minutes later before shutting down.