Loss of Boost.... Please Help!!!!

Like the title says i lost some boost. I have the stage 1 tune from infamoustuning. It was fine for awhile until one day i started my car in the morning and drove it, and felt like it was really slow. With the tune it used to spike to 17 and drop and hold at like 15-16 psi. Now it only spikes to 9 and drops to 8 psi. There is no check engine light on, and i cant see any boost leaks. Any ideas on what might of happened?? I wanted to plug in my tactrix cable and run a log but the freakin connection inside the tactrix obd2 connector just fell out, and now I'm waiting till i get it fixed. So I'm stuck with boosting only 8 psi and its so boring lol. Anyone please give me any ideas on what it might be. Thanks

Sounds like you are in limp mode. This typically happens when your knock sensor has picked up knock events/noise and the counts have increased to a point where the only way to counteract it is to retard timing and lower the ignition advance multiplier.

 

You might want to inspect all lines to make sure they are fully fastened. Also inspect your intercooler for signs that it has blown the end tank tabs. Inspect your turbo inlet for tears, anything air related could be culprit.

 

I seriously doubt the tune is bad, but it could be a possibility. Another issue could be bad gas. Also check/replace spark plugs every 60k.

 

If you don't do work yourself, start with a pressure test. If this yields positive results, move on to a compression and leakdown test.

 

Also, please provide your mileage.

Like the title says i lost some boost. I have the stage 1 tune from infamoustuning. It was fine for awhile until one day i started my car in the morning and drove it, and felt like it was really slow.

 

I seriously doubt the tune is bad, but it could be a possibility.

 

"It was fine for awhile" = not the tune

It does sound like its at spring pressure, but i dont think you can go into limp mode and not get a cel. I could be wrong though.

 

Btw, 17 to 15 psi sounds like stg 2 boost. Sounds pretty agressive for stg 1.

 

There is no CEL for limp mode.

 

Also, stage 1 to stage 2 boost is only 1-2 psi more (even on Cobb OTS). I believe the timing advance is more aggressive with the stage 2.

same thing happened to my tactrix. i almost shat everywhere when i saw it. i had to order a new one because sending it in for repair takes like 2 months

Also check the condition of your turbocharger. Check for shaft play and any rubbing on the housings. Its possible your bushings are shot and causing friction slowing down the speed of the wheels. This would definitely limit peak boost and create tons o lag.

It is a function of exhaust gas temperature. Too high an egt causes cat to go bye-bye.

in the case of stage 2, freer flowing exhaust allows less restriction on the turbine and higher pressures achieved.

My AP stage 1 map spiked to 16PSI, but I believe the target was 15PSI. AP Stage 2 I think had a target of 16.5, which means it spiked to 17.5-18.

Vacuum leak is my guess. You will probably need to take the IC off to find the vacuum line that blew off.

Thanks for all the helpful info guys, funny thing is I drove the car home after work today and all seems fine, the boost is there, pulls real hard like it did before. This is really weird lol, but I think that COMPSURGE is onto something with this. My co-worker/also a mechanic was just telling me the exact same thing as you did Compsurge. I did notice a small oil leak tho from the side of the intercooler right on top of the turbo. I changed my spark plugs like 5k miles ago, always use 93 octane gas from shell (v-power), and my car has currently 69k miles. I'm just waiting for my friend to finish repairing my tactrix obd2 connector so i can do some logging and see whats going on. I'll drive the car tomorrow and see what happens, with all the info i gave you, if you guys still have any ideas of what it might be please let me know. Thanks guys, you are all very helpful

I have had a lot of experience with IAM of 0 (limp mode).