Cant get over 5-10 psi without hardcore cutting out

[byrd126]

Im kind of new to the dsm world but not mechanicly inclined. I just put a maf translator and 3" maf inline right before the throttle body and installed a holset hy35 along with headers and a front mount intercooler. I did a boost leak check and several things were leaking but got everything fixed. NO BOOST LEAKS.(didnt fix the problem) Everytime i step on it full throttle it boosts fine until 5psi in first gear and 10 psi in second gear. Now everytime it hits the 5 psi or 10 it cuts out just like 2step would reving up. Its a 92 awd tsi with an automatic. I put new plugs in and the wires are about a month or 2 old. Any help would greatly be appreciated as i am lost!!!! Thanks!

 

[1990AWD]

What do you have for fuel system? What are you using to tune it with?

 

[matthewdesigns]

Please fill out your profile so that we know everything that's been done to your car...you haven't given us a lot to work with.

 

[byrd126]

Ok, I updated my profile. I have a walbro 255 and 450cc injectors. I am just using an air/fuel gauge until i can afford a wideband. I also have a datalogger but i dont have the cable yet. the cable will be here next week sometime

 

[DSMboostin15]

The 450's are most likely your problem. Have you taken any logs of the engine to see what it's doing? My guess is that you're running your injectors with the IDC of 100%, when you're supposed to keep them around 80%. To add to this, those injectors can only flow a theoretical 450cc, realistically it's about 430cc. They cannot keep up with the amount of airflow that the Holset is producing, therefore you're leaning out and most likely knocking, so you're hitting fuel cut to prevent damage. Someone correct me if I'm wrong here.

Do you have an AFPR for that 255? You'll NEED one to prevent the pump from overrunning the stock FPR.

By the way, that AF gauge is useless. It only reads the narrowband of the stock O2 sensor and is about as accurate as a 16th century firearm.

 

[viperlp01]

Im not going to even tell you what your possible problems are until you work out and PROPERLY modify your car.. You shouldn't throw a big ass turbo on and worry about tuning and fuel mods later.. The fuel and tuning should come first and then the big ass turbo..

 

[byrd126]

Thanks for the response. I just pulled out the maf translator and found a way to mount the stock maf just to see. I took it for a drive and it still hesitate just a little bit but once it hits the top end it has never ran that good before. It was a night and day difference. Do you think the 3" gm maf is bad? Or the translator? I took the stock 390s out and put the 450s in just to help out a little bit since a friend had them laying around. I have not logged it yet...im still waiting on the cable for my palm. I will get a wideband soon....I blew a head gasket in my cummins so im completely broke at the moment and have this as my secondary vehicle so i need it to run. Thanks! More input would be greatly appreciated!

Well my stock turbo had a majorly cracked axhaust housing and would boost 3psi tops. I had an hy35 laying around and no money...so therefore i made the hy35 work just to get me around.

 

[matthewdesigns]

Your MAF translator could be set up incorrectly, causing your airflow readings to be wrong. Double check that the switches are in the correct position. In general, I think everyone would agree that the stock MAS is a better choice than a GM MAF...they seem to be somewhat problematic and inconsistent.

 

[blakktalon]

You need bigger injectors as previously discussed, find info on how to adjust your maft,get a wideband before you end up with another dsm on jackstands,oh and a fmic wouldnt hurt either if you plan on making power with that huge turbo.

 

[byrd126]

like previously discussed i installed a fmic. It runs fine with the stock mas at 14psi

 

[BoostedBeaver]

You need fuel mods bad. I was on my 14b and at 17lbs I was at 99%IDC (injector duty cycle). This is bad and at that high of percentages a injector could fail. This is not to scare you only to make you realize that even if the maf or maft is your problem you are out running those injectors and probably running lean do this long enough and you will be picking up your pistons out of the middle of the road. Look at the upgrade paths on this forum to give you a good idea on what you really need. Please pay attention to what I and most of the others are telling you. YOU NEED MORE FUEL OR YOUR GONNA HAVE A BIG ASS TURBO WITH A BLOWN MOTOR.

 

[dsmspickdad]

Your maft and translator is not bad, it is just not set up properly. I do agree you may need more fuel but why it wouldn't work with the translator is cause it is not set up right. There are knobs in the translator.

 

[fstfcs]

Fuel son.

When i slapped a holset on my ford focus i was runnning 72lb injectors...converted to cc's they are fairly large.

My Talon has some nasty fuel cut issues currently with a big16g.....But in jan im switching to 850ccc's and dsm link