Problems after holset install

[godfather75]

I just finished installing my new holset hx35, now my car won't rev past 3000 rpms. I did a blt at 20 psi and have found no leaks, I tested my coils there fine, new wires, fuel trims around 100%. What else could I be missing, before my 18g blew it was pulling hard at 20 psi and now I get to 3000 rpms and it misses like crazy. Any help would be greatly appreciated.

 

[3kgt2nv]

did you retune it for the greater air flow from the new turbo? new injectors for the incresed airflow of the turbo?


both could cause it to break up as you run lean

 

[godfather75]

I have 750 fic injectors. My fuel trims are all at 100%.

 

[3kgt2nv]

what is your af ratio?

 

[DSMReviver]

Did it bog down, Check your timing.

And, did you mess with your cam angle sensor?

 

[LiquidX]

Your fuel trims are at 100%?

With your logger, what are your IDC% when your issue occurs?

 

[godfather75]

Haven't messed with the cas yet, I have another one I'm gonna try on it in the morning as well as another tps.

Fuel trims are between 98 and 100, I haven't checked idc yet I will in the morning.

 

[LiquidX]

Unless you have a timing light, don't mess with the CAS. As for the TPS, as long as the voltage is set properly, it's working. What boost level are you trying to run? Also check your plugs.

 

[untouchablecc]

I doubt this would cause you to not spool past 3k but it would cause a misfire. Gap your plugs down to around 22 23 if you have not already. My car would break up when i went up to a holset because my plugs had the wrong gap.

How is the shaft play on the turbo?

 

[Misterbeechy]

yea flow is the issue... 20lbs of boost on one turbo isnt 20lbs of boost on another.. ... start tuning buddy.. or look for boost leak anywhere..

it would have to be simple.. i mean all you did was swap turbos?

just re-tune for more or less flow..

 

[godfather75]

I have a timing light so I can try the cas. There are absolutly no boost leaks. My plugs are gapped at .028. As far as boost I can't even get past 5psi without it breaking up like crazy. The last few weeks before my 18g blew it was starting to have a slight miss but nothing like this. I thought it was the plugs so I changed them out for ngk7's.

I have a dsmchip in it and a maft translator with a logger to tune with I may have to get something better in the future.

 

[3kgt2nv]

gap your plugs down check your coils and make sure for afr is set properly. if this turbo is spooling slower or faster you might be running lean or rich. also check your o2 sensor as this can cause issues with the ecu trying to adjust afr and injectors

 

[Misterbeechy]

oh ok.. sorry.. i thought it was only happening when reaching 20lbs... ummm it could also be an ignition coil may be going ..

 

[godfather75]

Car fixed itself this morning on the way to work pulled hard at 20 psi of boost. Now on the way home from work back to no acceleration above 3000 rpms. I'm thinking I might have another bad gm maf, this is the 3rd one in two years.

 

[90moneypit]

Double check all the wiring (especially your O2) to make sure you didn't pull something loose while wrestling the turbo in. Another likely culprit could be your dsmchip being programmed for a smaller turbo and the Holset is leaning everything out with the extra flow. It's all fuel/air/spark/timing and if you have the fuel and timing and think your gap is fine (might want to try cleaning and re-gapping the old ones as a test), then it's down to air flow. You did mention having problems with the GM MAF but I'd still check everything else first if your logger isn't recording erratic readings.

 

[untouchablecc]

I have had better luck with junkyard gm mass then rebuilt ones at a parts store. If you have a local scrap yard you can go into i would pull a few off just to keep on a shelf.

 

[jed344]

had the same issue when one of my coil packs were going.

 

[turbo tim1]

I had a similar issue and it was a wire going to the coil pack was almost broken, it was barely connected.

 

[richard33]

so you had these issues before you put the holset on. It sounds like ignition related problems. The car didnt fix itself if the problem still persists btw. Change the coil pack and tune the car.

 

[LiquidX]

Have you checked the PTU?

 

[EclipticalGS]

Test the coil packs and/or replace the PTU. Also check the wiring going to the coil packs..They could be frayed or rotted out from them grounding out possibly..

Anyone saying to re-gap your spark plugs please stop..The car can't even hit 5/lbs of boost until it starts breaking up... His plugs could be gapped to .028 and still probably handle 20psi from that hx-35.

 

[godfather75]

I know the car didn't fix itself, I just meant it went away for a minute. I tested the coil packs but I'm gonna switch them out today anyways. My plugs are gapped at .028. Is there any way of testing the ptu?

 

[3kgt2nv]

i would try gapping the plugs down a bit to make sure your not getting spark plug blow out. drop them to like 24-25 gap

 

[godfather75]

I changed the maf last night, checked and closed the gap to .026 on the plugs, and checked the cas and the plugs are sparking. I reset the base timing to 5 degrees btdc.I thought for sure I had it fixed because when I swapped my maf out I found that my meth selonoid was not shutting off and leaking meth back into the intercooler pipes. So I fixed that, a wire came loose off the solinoid. Went for a drive and it is still breaking up bad at 3k and no boost over 5psi. I am gonna try the coil packs this morning hope and for the best.

 

[viperlp01]

Are you still spraying meth?? If you are that is the issue. I could not run meth at all with the gm maf. I really wish you would not focus on fuel trims that much and actually spend the money on a wideband. An ecu's calculation of the fuel trim is based off very vague numbers giving off by a semi inaccurate o2 sensor and now your damaged gm mafs. After the first time the meth sprays that water leaks back and touches the hot wire part of the maf and spikes the signal as high as it goes causeing a super rich condition. Plus the meth is spraying so your adding even more fuel. Recomendation... before you start messing with it again spend the 200 bucks and buy a AEM WB02 so you can actually tune the car. Your going to blow it up with a holset on there.