Looking for suggestions. Have read a pile of posts and still puzzled. Backstory: Just purchased car this week. 2008 MCS with 73k, super clean, few mods; Alta valve and Alta manifold adapter, CAI. Test drove car last week with CEL on but ran fine. Good boost, per standards started around 1800rpm and built from there. No issues. Seller had appointment to take in to check codes, which he did, prior to me purchasing. Codes came back as P0300-P0304 misfires. They recommended injector clean, blah, blah. My guess was HPFP. Anyway, struck a deal and bought car as-is for a good price. Picked up car and drove 20 miles or so and stopped for food (150 mile drive home). I think it was running correctly and was building boost at that point but I can’t honestly remember. I did drive it for a short time in Sport mode. After 20 minute stop to eat I dumped in a bottle of fuel injector cleaner/carbon deposit remover, fired up, pulled out and in 30 seconds the Safe mode warning displayed on tachometer display. It was definitely in low power mode but had to get it home so drove the 120 miles home. Dropped it off to get it detailed when I got home so didn’t dive into diagnostics right away. Picked up from detail shop and drove home, CEL on but not safe mode indicator, but still in low power mode. Car has boost gauge and I could see no boost at all under any throttle conditions. Got it home and scanned with my BluePoint scan tool and got same P0300 codes. I’m not sure if the shop that looked at it actually cleared the codes or if they came back right away. I cleared codes, and disconnected battery for 30 minutes. Car starts and runs fine but builds no boost whatsoever. I checked all vacuum lines and see no issues. Manually applied vacuum to wastegate and it appears to be functioning. No CEL is currently on. Is it somehow still in limp mode with no CEL or MIL? Can’t believe it’s major as it ran great during test drive. I just can’t recall if it was ok before the limp mode light came on. I think it was but..... Any thoughts or suggestions would be welcomed. I am extremely mechanical so I’m comfortable digging into this I’m just stumped at why it totally lost boost with no apparent reason. Turbo shaft has a fuzz of play but I can’t believe that would cause a zero boost problem.

 

After some head scratching and pondering the situation while cutting the grass I tried a few tests. I connected a hand vacuum pump directly to the waste gate and verified it’s moving and held open, so no leaks at the diaphragm. I drive the car and under medium throttle had 6+ psi boost! Thankful the turbo seems good! And confirms my thoughts of it’s something simple. After that I connected the wastegate directly to the vacuum pump and test drove, again boost but also set the engine light in the tach. So it seems an issue with vacuum being applied to wastegate via boost solenoid. Is it possible the ecm is not applying a signal to the solenoid for some reason or faulty solenoid? Any input appreciated!

 

Unfortunately, there can be a number of reasons for this. First off, check your diverter valve on the turbo. They are notorious for the diaphragm tearing and you will not get consistent boost, if any. If not that, and the vacuum system seem ok, it may be worth replacing the boost solenoid/ pressure converter (seen it called both) to see if that’s the issue. They are a bit spendy to just throw at it in hopes of a fix, but there are some on eBay for about $30 used. Unfortunately I haven’t really come up with a good way to test them off the car.
Hope it’s an easy fix for you. Last resort, pull the downpipe and check the wastegate. When mine went out, I was getting codes and limp mode like crazy, but it looks like you only have misfire codes right now. There is always the possibility that it is getting worn out, and like mine did, will build some boost, but not hit the boost target, hence the codes. But that was the famous 2885 code for boost pressure. The misfire could be as simple as needing new plugs and/or coils. One way to check is to move (one at a time) the coil and plug to a cylinder and see if the misfire moves with it.

 

I ran some more tests today. Vacuum at pump is at least 30inhg, but getting no vacuum to the wastegate at all. Pulled intake and bench tested boost solenoid by apply voltage across it. Appears to be opening and closing correctly with vacuum applied to it. I thought for a moment that the purge solenoid and boost solenoids plugs may have been switched but I’m not sure. Right now the car is stuck in limp mode with no codes that I can pull with generic OBD tool. Strange it is in limp mode with the icon on the tach display but no cel in the speedo display. I can tell from my scan tool that I have 750 psi at fuel rail at idle and up to 1500 at 4,000 rpm. At this point I have no vacuum to wastegate to close it and build boost but that may be due to being in limp mode. Also the stock diverter has been replaced by a ALTA vacuum diverter. I need to research if the diverter mod requires a tune since the wire is no longer plugged in an just left hanging.

 

Part of the problem is that in limp mode, it basically doesn’t allow the wastegate to close, effectively bypassing the turbo. The other thing is that you should not be seeing vacuum at the wastegate unless it is under load. The boost tables are load based, not engine rpm. You won’t get boost unless you are driving and under load at that.
The other issue is that with a generic reader you will not get all the codes, that’s why you are still in limp mode I would guess. You NEED to have something like the Schwaben scan tool fromECS to read and clear all of the codes.

 

After starting several times, and the limp mode not turning off, I decided to drive the car. It immediately had boost and seemed to run correctly even though limp mode icon was still displayed. After 3 miles of driving and a couple easy pulls the limp mode icon turned off and everything seemed normal. Went for a 40 mile drive and all is good. I really think the connectors were switched at the boost and purge solenoids. The connectors are not keyed to be unique to the specific solenoid and do not appear to be color coded either.

 

Feel kind of ignorant for asking but was is "limp" mode.
I'm new to the MINI club

 

There is a Check Engine Light (CEL), also called a Malfunction Indicator Lamp (MIL) in the speedo display. This can come on for a variety of reasons and will indicate there is a fault code stored. That car should run correctly. In the tach display a picture of a half shaded engine may appear which is the indication the car is in “safe or limp” mode. When in limp mode power will be greatly reduced to prevent engine damage.

 

Hate to ask- but could anyone get a pic of these connectors? My car is acting very similarly after replacing the brake booster vacuum pump, but I dont believe I unplugged any electrcal connectors except the PCV heater.

Thanks--

 

Also I believe that the ECU keeps the injectors in the low power state as well in limp mode.

ZeroLav, if you didn’t unplug them, I doubt that’s the problem. They are under the intake manifold. The best thing to do first is get the codes read. And if it’s in limp mode, try this, cycle the ignition once or twice then drive it.. come to a complete stop on a hill or decent incline (going uphill) then start driving again. That should clear the limp mode. I know it sounds weird but I got this straight from a Mini tech.... and it really does work. Done on more than one Mini

 

Thanks MrGrumpy, though finding a hill around here may be troubling...

 

Didn't work for me. Here's what I did
Key in, key out
Key in. key out
15 mile drive, no turbo.
Big orange light came on after first mile or so.
Found a "hill", stopped at the bottom and sat a bit, car I'd drive and running.
Drive gently up said hill.
No change at all.

Gonna try to catch the dealership service dept first thing tomorrow morning.

 

Minor update- according to Torque app I'm making between .2 and 2.5 psi in Sport mode if I really flog it.

 

That will happen in limp mode. If it’s not in limp mode, that’s probably why it was. Have you had the codes read?

Hmmmm, it usually works almost right away.... you have to be going up the hill when you stop. Stop then go on a hill. No biggie as long you can get it to clear one way or another. I got to where I could pop back out of it in just a couple of minutes when i was having turbo problems. Technically the ECU needs to see the engine clock a certain number of times or something like that he said... but you can usually kind of cheat it like that, or clear it with a scan tool.
Not even he could tell me what a clock of the engine entails, but did say that part of it is stop and start on an incline, accelerate to highway speed (iirc), and warming up from a cold start, we’re all part of it. But I’ve always been able to cheat it like he told me until I got a scan tool for it.
Im just passing on what I was told and hoping it helps.

 

I'll give it another shot. Frankly, my hill sucked. I know where there's a great one farther out. I have the torque app, but it's just giving me the same historic code over and over, and that code wouldn't trip limp mode.

I'll let ya know.

 

Good luck.
I just glanced through the thread again to refresh my brain. When you replaced the vacuum pump, I am assuming that you reconnected the vacuum line to the vacuum reservoir towards the bottom of the pump? There should be 2 lines to it. One to the brake booster and one to the vacuum reservoir, which then goes to the boost pressure converter. You could have a vacuum leak somewhere in there possibly. That’s what controls your wastegate. Sometimes those lines can get soft and collapse under vacuum too. Do you have a vacuum test pump? They are only a few bucks at harbor freight.
hard to say without any codes. Another thing you can do is try what the OP did, and plug the wastegate actuator directly into the vacuum pump and see if you get boost

 

The small line on the bottom of the vacuum pump was reconnected when I did the repair, popped off the next day, and put back on. Hasn't come off since. I tried tracing it to make sure the other end is connected, but it gets lost among the other lines and cables under the intake manifold. If you can point me to the vacuum reservoir I'll check there, assuming I can find it. Sitting at a pizza joint at the moment. Heading to that great hill after lunch.

 

All fixed up. For those interested: when the vacuum pump went ****-up, it filled the vacuum line and the reservoir with oil. Since the vacuum wasn't getting where it needed to go, the wastegate was stuck open, so no boost.

Vacuum lines and reservoir were removed, cleaned and replaced. Everything is groovy now.

 

Curious if you had the issue pop up again, or if it's still all good?

Thanks