sureshot

Hi All,

I have a big problem with my 2008 CS and really hoping someone has some advice!
I have tried to search this and other sites to find something similar but nothing really fits my situation.

So I was getting P2404 codes almost daily - small evap leak. I could find no leaky hoses or connections after testing with propane and listening for hisses and it seems some owners had got success with fixing this by replacing the vacuum pump. So I got one, stripped down the intake manifold and valve covers and removed the throttle body to get access to the pump at the back. No big issues with that, although it is a pretty fiddly job at the back of the engine swapping out the pump. I checked all the gaskets which seemed sound, gave the throttle body a quick and gentle clean with some carb cleaner (but did not move the vane inside) and put it all back together. I used the Pelican guides for all of that and don't think I missed any steps stripping it down or reassembling. After reconstruction, the car started but was very rough, like it was missing on multiple cylinders. The car was vibrating and rocking badly. So I stripped all down to recheck connections two more times before putting the old pump back on to see if it could at least get back to a driveable state like it was before I started. I'd read that there is a reset procedure which may have helped with the PSM (disconnect battery, reconnect, on/off ignition a couple of times then fire up), so I followed that and hoped for the best. Nope, still the same. In addition to the roughness, the car quickly shows PSM failure on startup and PSM button does not work, engine will not rev over 1500rpm or drive over 10km/h. It has no power to even climb a modest slope. When I take the cap off an unused port on one of the vacuum lines, I cannot really feel any vacuum or pressure. I have a vacuum gauge but not sure if I was using it correctly. I did attach it to the unused port but it did not register anything. The car did not register any codes until the last rebuild. I don't have a great OBD scanner, just a cheap $50 one but it did show codes P2123 and P2127 which I have not seen before. Battery is about 6 months old, only other issue with the car is an occasional code thrown for P0421 which I think is a failed post-cat O2 sensor which I have and was going to do next........

I'm really stumped and hoping that someone reading this knows what the problem is. At this point I fear I may have to tow it to the local dealer and sell a kidney to pay them to fix it.

I'd be really grateful for any advice or knowledge!

Thanks

Andy

Petza914

Although the battery is 6 months old, what's its current state of charge. The PSM error will illuminate when you disconnect or have a low battery. It will clear on its own once you drive the car a few feet, but since you're having this other issue with the way the car is running obviously aren't driving it, so the error remains. First thing I would do is disconnect the battery under the seat and fully charge it, then hook the cables back up and start the car to see if it behaves the same way.

Don't worry about the PSM light though.

sureshot

Thanks for the reply Petza!

OK, so I am not as thorough as I thought! It turned out to be the electrical connector on the throttle body not being pushed all the way home.

Thanks guys!

Petza914

Awesome. Can't hope for an easier fix then that. Nice detective work.

sureshot

So the underlying problem that caused the fault code, rough idle and loss of power is now fixed properly. I swapped out the vacuum pump and replaced the throttle body and intake manifold gaskets. She now runs like new and is smooth, powerful and quiet. If you have these issues, this is a fairly cheap fix with parts all in costing about $350 CAD and taking about 2-3 hours in labour. It is a bit fiddly doing the vacuum pump, but a short stubby ratchet really helps. No fault codes since the work was done and she absolutely flies!