I have a 2009 HHR SS with the stage one upgrade.
It was running great for a few months, but now it will occasionally fail to produce any boost at all.
As I ease into the throttle, I normally see the boost gauge go from pulling a vacuum to producing 21 psi. When it fails to produce boost it will still pull all of the way to the red line without missing or stumbling, it just doesn't get there very fast. If I back out of the throttle and then nail it, it will engage the turbo and give me around 21 psi.

I took it to the dealer and advised them of the problem. I also asked them to check the connections on the new sensors installed with the upgrade.

They say the sensor connections are fine and that they reprogrammed for the stage one and the vacuum pump fix for the brakes.

It ran fine when I drove it home from the dealer, but it failed to produce any boost this morning.

Any suggestions?

 

Its your sensor hitting the AC condensor. I read the first line and knew what was up

 

Why has Gone Mad not issued a TSB to the dealers on the potential for sensor contact at the AC condensor? Someone please tell me, why not? If it is so common, there should be information out to advise dealer technicians. Tapping foot here! Arms folded, scowl on face. Get with it. At least a P/I......jeez.

 

I was the one to first solve the AC hit issue with help of the GMPD staff.

To check to see if this is it take a piece of foam or carboard and stick it in between the Map on the lower pipe and the AC unit.

What happens it the Engine torques back and lifts the pipe up and back into the AC compressor or line. This normally only happens under hard acceleration and at lower boost. The load has to be on the engine at lower speeds.

If you ease into it generally the engine moves little and it does not happen.

From what you discribe I ten to think that it is not hitting. But it is an easy thing to check. If it is hitting the Intercooler just needs shimmed forward with washers.

Some of what you discribe fits but there are some conditions that you discribe that don't.

 

Might call em and ask?

 

I've gone through the same issues and more and I don't think it's the sensor hitting the ac compressor, given the fact it looses boost for such a long period.

When mine hit the ac compressor under torque, it would cut off power in an abrupt manner then come back on.

I'll bet you dollars to donuts that the wires spliced from the new sensors were not performed properly and have a clean connection. It takes a constant 5v connection to keep it from doing what the op described.

Now to backtrack.

I had the turbo upgrade installed and after many trips to the dealer it turned out they broke a vacume hose.

Then I noticed hard off the line it would stumble, so I added the ttr hard motor mount (it helped but did not cure it), then moved the inter cooler up 1/2" wish washers. Once again it helped but did not cure it.

Then this week started getting surging and a drop on the highway to zero boost, then back up, then back down then more surging.

I took it to my local shop (I've given up on the Santa Monica dealership) and we checked the wired on the top sensor. There were holes in the crimps and they were touching each other. We heat sealed the crimps, separated the wires and now it runs great.

One more note. With the auto, regardless of the mode you set it in, comp, tc off, or even esc off, if you come off the line hard with traction it will shut the power off, then on then off as if to protect the transmission or do some form of traction control correction.

If you come off the line spinning the tires, no drop in boost, no problems.

So I probably will add a tune that will override this.

In summary. First, check the crimping connections. I bet they've been done in a half ass manner.

IMO

JR

 

See ? All these problems w/ the Stage 1 upgrade is why i dont want to do this. TOO MANY PROBLEMS !!

 

Not really that many issues in the big picture of all the kits sold only few have issues. Most that have it never complain.

Often many of the issues the Upgrade kit has is something that can go bad on the stock kit too.

What little pain for the gain is more than worth it. Note my issue was due to the dealer installing a replacment intercooler after an accident. It was just spaced back more than stock. It was fixed under warranty and never another issue.

Most issues are just due to techs installling the conectors improperly. If they had done them right they would work fine.

If you are happy with less power and 15.20's that is all that matters. Now that I have the extra power would never go back.

 

Thats ok if you like to putt around especially with the auto trans the stg-1 makes a whole different car out of it there are plenty of answers to any problem that can arise Stage1 is my favorite upgrade.

 

What makes you think they haven't? PIP4720A