Where's my boost!
 

My intermittent boost problem was solved a few months ago with a new Bosch aux. water pump but this week, with no real symptoms, there's no boost at all (fuse #23 for the pump is ok). I replaced the Intake Air Temp Sensor thinking it may have failed but the new unit from MB made no difference. Any ideas? Do the SC clutches fail like this? The car has 84k on the clock.
Thanks for your help!

Re: Where's my boost!
 

Are you monitoring this with a boost gauge?
How often do you drive the car - could you have air trapped in the system?
Do you have something to monitor your IATs?

Re: Where's my boost!
 

Confirm the new pump is still operating. Maybe one of the wiring connectors isn't fully seated. It happened to me.

Re: Where's my boost!
 

You are right on with the things that control weather or not you have boost. It sounds like the first thing you should do is make sure the IC lines are purged and you have power right at the IC pump. Clutch failure is not common. It sounds like it is not engaging like you said and if you can't check IAT's (cheap scan gauges for $30-$50) then you may have to do it the ol fashion way. See if the IC pump is really pushing coolant, start the car, drive it (has to be in a drive gear) up to about 2,500 RPM, park it and leave it running, pull a coolant hose off the outlet IC pump side to see if coolant is flowing (instead of getting under the car pull the return coolant line off from above for less mess). I was able to avoid this by listening to and feeling that my pump was working even while the engine was running but it needs to be on ramps/jackstands.

Re: Where's my boost!
 

Not sure what kind of nominal voltage runs to the pump, but since it's not an "always on" circuit, perhaps wiring up an LED to the connector would be a simple start?

You're correct that the pump is not always on, but if I remember correctly, once it turns on it will run until the car is shut off. I think Woody (waldig) has a You Tube video that shows this ... by using LEDs to show when it's on and when it's off. So, what Jesse suggests would turn the pump on and it will stay running until the car is turned off.

Re: Where's my boost!
 

Just install a jumper wire and see if it turns on. Its a 15 minute job.

https://www.crossfireforum.org/forum...-pump-srt.html.

Re: Where's my boost!
 

Now these ideas are way too easy, I don't know why I was trying to get you to make a coolant mess.


I have the silver switch mod from Rudy that uses an OEM rocker switch and a control module but have never installed it, I couldn't even find a thread mentioning it. Anyone see this before?

Re: Where's my boost!
 

Rudy decided not to market it except to those he knows well...as it could cause problems if misused. If it isn't on, hopefully you have checked all the simple things 1st like fuses, and if air is in the system if you didn't burp the system after installing the pump, well that can do it too...

Re: Where's my boost!
 

I don't have a boost gauge or any way to monitor the IA temps. I would think that I should have boost when the engine is cold, but that's not the case.
Been driving the car daily since replacing the aux water pump, watching water temp gauge often, no signs of high temps.

Re: Where's my boost!
 

Even if the pump isn't running I should be able to feel some boost when the engine is cold, if only for a short time, correct?

Re: Where's my boost!
 

You said you checked fuse #23. The fuse for the pump is #13 a 10 amp red fuse.

Re: Where's my boost!
 

This can happen during install...touch a wire wrong...and zap...better to unhook the battery when installing. So, if you didn't, check the fuse...

Re: Where's my boost!
 

You are correct. If you aren't getting boost when the car's cold, then something else is happening. As I believe someone already suggested, you could connect a test light to the wires running to the electromagnetic supercharger clutch. Drive the car and see if the light comes on. If it doesn't, then it's not getting power.

https://www.crossfireforum.org/forum...ns-always.html

Re: Where's my boost!
 

great thread Anthony thanks for posting it.