firemangeorge

Wonder what the dealer visit outcome was ?

Nazgul 9

Sorry it took me so long to get back and let you know what was going on so took the car into the dealership there and several different tests on the Turbo System including wastegate and blow off valve couldn't find anything they checked all the electrical connections including everything that went involved was involved with putting in the GM performance upgrade couldn't find anything they sent the information on to GM GM got back to them the next day told me to bring it in and have them do a boost check on it it passed with flying colors no problems at all with the Boost or the turbo
so I sat down with the service manager at the dealership and he explained to me basically everything they didn't find and he had a recommendation he says I should try to find somebody with HP tuners and a Dino so that I could actually test the system in real time with that being said I believe I am going to take the car up to zzp and talk to the gentleman there that I know and see what we can do about figuring out what's wrong with the system and why it's doing this so until I can take care of that I still have no idea what's wrong but I do appreciate all of the feedback and the great suggestions from everybody because I did go go through this the particular thread and show everything to them there at the dealership and make sure that everything that could possibly be checked was checked and that's where I stand as soon as I figure it out what's wrong I will absolutely let everybody hear know thank y
you

PulpFriction

Sorry about the edits to your comments but it was to help me read it and not miss anything. I don’t think you answered about what fuel you’re using. Also, any chance they scoped the intake to look for carbon on the intake valves in particular, but also in the combustion chamber? What’s the oil change history? What oil, exactly? Any mods to the intake at all? Stock air filter? (Sorry is I missed any prior answers.)

Nazgul 9

I use 93 in my hhr,, They did indeed check the intake and intake valves,So this car was purchased brand new by an older couple who when they sold it to me gave me a folder with the paperwork from the day they got it till they sold it to me and all work done on the car was done by the same repair shop for the entire time they owned it and oil changes were done every 3k miles using mobil one,
It does not have a stock air filter but it was changed by me over to a K&N filter but the problem was there before i did that..
I have not contacted ZZP yet but i will be doing that this week

Will update this has i get new info
Thanks for all the help
Vince

firemangeorge

Any way you could post some current pictures of the Tmap sensors and their harness connections ? Both the upper and lower ones ?

Edit: Also. Where did you purchase the GMTU kit from ? The Chevy dealers haven’t had these kits for many years.

PulpFriction

Just reviewed and don’t think anyone asked how many miles. Also, what spark plugs? Gotta be AC Delco 41-108 (iridium.) No substitutes. No “just as good ask.” No “They make it for GM.” No “better than.”

Prior owners may have babied it and/or made a lot of short trips. If so, serious coking of the intake valves would be a surprise, but excessive carbon in the combustion chamber might. This can mean hot spots and knocking that didn’t happen until the GMTU with maybe more aggressive timing advance and/or higher boost. (I don’t know much about that tune.) The knock would, again, cause the timing to be rolled back, which would cause the exact behavior you describe.

You could try some sea foam or detergent additive in the fuel, then take it for a long brisk freeway drive and try to burn off any carbon. (There anre anlso products specifically for this that I don’t know much anbout.)

Also, “Top Tier” gas sounds like marketing bs but that really does mean more detergent than the minimum government standard. It really does reduce carbon accumulation. Major brands have it in all grades: Sunoco, Shell, Mobile… except BP. Bargain brands mostly don’t. I went this way a couple years ago and I notice quite a difference. toptiergas dot com.

Or, seriously, run the tank down and try a few gallons of 100+ octane racing fuel.

You could pull the plugs and peep in there and see if there’s a lotta carbon.

firemangeorge

Wonder what ever happened ?

Nazgul 9

Sorry about that things have been kind of hectic here and for right now at least I don't have the time or the money to take it over to someplace else and have them run Diagnostic and and then put it on a Dyno and figure out what's going on so I'm going to wait until spring and then get it into zzp and have them take a look at it and see what they can tell me it's just right now I just I don't have the time for it other than that I've tried a few other things putting in higher octane gas even though they had been done I actually redid the spark plugs and yeah none of that has worked so like I said I'm going to put this on the back burner for the moment and pick it up again in the spring I absolutely appreciate all of the input and stuff you guys have given me thank you so much

Oldblue

We’ll wait, life is what happens while you’re busy making other plans. ZZP is an excellent choice.

RJ_RS_SS_350

Yep, we'll be interested to see what the problem is!