Troubleshooting my VRT

[R32Smoker]

So I've been struggling with a few issues with my VRT for too long now and am in need of some advice/suggestions.

The setup:
-Fully built VR6, 8:1 compression
-Precision 6265 t3 4 bolt, .82 a/r
-UM 630 tune, 630 injectors
-Walbro 255
-C2 short runner intake manifold
-4" maf housing, about 12" from turbo
-Tial 38mm wastegate
-Greddy Type RS BOV, recircualted


Symptoms/Problems:
-Error codes 17535 and 17545; bank 1 system too rich additive and multiplicative

-Cannot run more than 16 psi without massive hesitation/loss of power. It's inconsistent also, sometimes it feels pretty strong, other times it feels like I've hit a brick wall.

-On the dyno it made 315 whp, 355 ft-lbs by 4000 rpm, than went jagged/flatlined as soon as full boost kicked in. Power delivery was fine when just running off wastegate though (14 psi)

-Sometimes idles fine, sometimes idle fluctuates up and down randomly and occasionally wants
to stall out (not as big of a deal as the other issues)

Parts I've replaced:
-Coilpack (now running DUI Screamin Demon ford coilpack)
-Wires
-Plugs (NGK BKR7 at various gaps, now running BKR8EX at .030)
-2 new OEM MAFs
-Front o2 sensor
-ECU and entire wiring harness(!)
-Smoke tested for vaccum leaks; none found

I've ordered a boost leak tester to pressure test the system so I should know within a few days if it's a boost leak or not. Any other ideas of what might be going on if it's not a boost leak?

[MRosier]

I have issues with hesittion/brick wall feeling during the onset of acceleration once full boost hits at wot at anything over 11 psi or so. Ive found that im just blowing out spark and had to close the gap to like .025 or less on my ngk bkr7es. Stock coil pack. No cel or anything though

[Vdubsolo]

id check for boost leaks.. if you have a beefed up igniton set up you probably arent blowing out spark.. presure test your IC pipes..

[R32Smoker]

Pressure tested today and found a massive boost leak from injector 1. Are Siemens 630cc injector O rings standard/stock sized?

[R32Smoker]

Found the o rings at autozone and replaced them; stopped the leak, but no change in the way the car drives

[Scrubbs]

Drive it and when it misses, turn the car off and stop the motor,as fast as possible by pushing in the clutch and pull over, and pull the plugs, and scope the pistons. Post pics of the plugs. And put a guage on the fuel pressure and watch it too.

[Vdubsolo]

Ive been out of the vw game fr 2 years with my vrt sidelined, since then Jeff from c2 is with UM.. so please excuse me for not being completely up to date.. but why arent you running a Pro MAF with the 630 injectors and software?

[R32Smoker]

I'm running the stage 3 software for the 12v which uses a 4" maf housing, not the pro maf. They only list the pro maf as an option for the 24v on their site, not sure if it's available for the 12v or not.

On a related note, when the shop was troubleshooting the car, they unplugged the maf and drove around for a bit to see if it ran any better, and it instantly idled much better. The maf was only about 7 months old, but we replaced it anyway. It didn't make much, if any, difference. I've got the maf as far away as I can fit it with my setup, it's about 12.5" away from the turbo which should be enough right? Why would my car run smoother with the maf unplugged?

I also think there are still some leaks in my system; I got rid of the two major ones which were easy to hear, but it still doesn't seem to be holding pressure like it should. I need to spend some more time with some soapy water to pinpoint the problem.

[R32Smoker]

Compression tested my motor today. I was expecting low numbers since I'm running 9.0:1 compression pistons and a head spacer (total of 8.0:1), but do they seem a bit too low? The motor has around 25,000 miles since being built.

Here are the numbers:

#1 100
#2 90
#3 90
#4 88
#5 90
#6 89

[huichox4]

Compression tested my motor today. I was expecting low numbers since I'm running 9.0:1 compression pistons and a head spacer (total of 8.0:1), but do they seem a bit too low? The motor has around 25,000 miles since being built.

Here are the numbers:

#1 100
#2 90
#3 90
#4 88
#5 90
#6 89

why are you running that low compression?

9:1 pistons should be fine, ditch the head spacer I say.

what exhaust do you have?

close the gap on the spark plugs too, .022-.028

[R32Smoker]

I do want to pull the spacer, I don't need the compression that low (it was built by my buddy to be balls to the wall, he passed the project on to me). It's just this car is my daily driver and I don't have the time to pull the head at the moment. It's on my list of things to do though, and I'm sure it will run better when I do, though there are some other issues going on. It will give me a chance to check out the piston rings and valves, maybe even throw in some cams if I'm feeling squirlly.

Exhaust is 3" EIP with no cat.

My car actually ran worse when I closed the gap on the stock coilpack, it caused it to die out at idle more often. I'm running the DUI coilpack now, so I don't think I need to run that small of a gap. I can give it a shot though.