Stumped by a 1999 E350

Derek@Vision Diesel · Jun 14, 2013

Alrighty ladies and gentleman.... looking for a little guidance.

E99 E350 van with 150k miles on it.

We put 200/100 injectors, T500 oil pump, Hydra chip LIVE TUNED by Bill, BTS transmission, stock turbo with WW2, and some slight fuel system modifications to allow it to hold 65PSI. Swamps IDM.

It drives around fairly good in all tunes under 3/4 throttle. It will put you back in the seat and drive pretty smoke free even in the hottest tune at 3/4 throttle.

In the hotter tunes (say #5 and #6), you go past 3/4 throttle from a rolling start and is a little laggy then lights and pulls hard, after about 1 second of pulling hard it chokes itself off completely and POURS black smoke out the back. I am talking much worse than the worst of 12v's. It will stay choked out for a few seconds until you let off it. It generally happens around 3k RPM.
To explain it more simply, it feels exactly like the back pressure valve is being forced closed. It loses all power and just pukes.
The odd thing is this van WILL NOT build more than 15psi of boost and 25psi of back pressure. When the choking happens it drops down to about 6-7psi of boost and 12-15psi of back pressure.

Fuel pressure is steady above 60psi
ICP is 3000-3200 the entire time
IPR DC% is never above 42%
Map sensor and mechanical gauge both read the same boost readings.
Deleted the back pressure valve completely
Checked over it for exhaust leaks about 10x, it is VERY clean.
Have inspected for boost leaks multiple times (no IC so its very easy)
Passes all tests we can do in house with flying colors (contribution, KOEO, KOER, buzz test)

I have nearly ran out of ideas and what to check. It is very sound and runs absolutely great until you go past 3/4 throttle.

Sorry for the long post, its been a lengthy process trying to find the issue.

Anyone experienced this?

mandkole · Jun 14, 2013

MAP sensor issue? Air filter being collapsed?

What is strange is that it only does it in file #5-#6. Its likely running at similar/higher boost pressure in the mid range tunes but does not do it. Tuning issue?

Derek@Vision Diesel · Jun 14, 2013

mandkole said:
MAP sensor issue? Air filter being collapsed?

What is strange is that it only does it in file #5-#6. Its likely running at similar/higher boost pressure in the mid range tunes but does not do it. Tuning issue?

It isn't a MAP issue as the map sensor reads identical to what it should read.

Waiting on some new tunes for the thing to figure out if that could possibly be the issue, but it truly doesnt seem like it.

kyle43335 · Jun 14, 2013

air filter collapsing sounds like its worth a look. how about thrust bearing damage in the charger? def worth a look.

tuning issue would be on the list of maybes also....

just throwing ideas out there.

mandkole · Jun 14, 2013

Derek@Vision Diesel said:
It isn't a MAP issue as the map sensor reads identical to what it should read.

Waiting on some new tunes for the thing to figure out if that could possibly be the issue, but it truly doesnt seem like it.

I misspoke-- yes, the map output is matching. What I was thinking on, is this an issue where the map sensor is being maxed or is suddenly unhappy in a moment of heavy boost ramp rate. However, the mechanical events that are occurring in 5&6 should be occurring in the other files as well.

My vote is that air is suddenly being prevented from entering, or there is something going on with the 5/6 files.

TyCorr · Jun 14, 2013

Maybe those two heavier fueling tunes are raping the charger. Overfueled, oversped.

Derek@Vision Diesel · Jun 14, 2013

kyle43335 said:
air filter collapsing sounds like its worth a look. how about thrust bearing damage in the charger? def worth a look.

tuning issue would be on the list of maybes also....

just throwing ideas out there.

I agree on the filter thing, as these vans don't have the easiest access for aftermarket stuff. We have the highest flowing filters we could find in the factory box. with the 2 filters those vans come stock with (flat style), they should flow enough for a WW2 and stock charger, don't ya think?

The bearings feel nice and tight in the charger, have checked them a few times over the last couple weeks.

Thanks for the ideas! Tuning is my next thing to check

mandkole said:
I misspoke-- yes, the map output is matching. What I was thinking on, is this an issue where the map sensor is being maxed or is suddenly unhappy in a moment of heavy boost ramp rate. However, the mechanical events that are occurring in 5&6 should be occurring in the other files as well.

My vote is that air is suddenly being prevented from entering, or there is something going on with the 5/6 files.

Forgot to mention I tried a boost fooler, thinking maybe the map sensor was unhappy...even though bill doesnt allow for overboost codes, it was just something to rule out.

I have NEVER seen this vehicle build over 17psi with the WW2 and 200/100, non wastegated 1.15 housing, and no IC. Seems as though that is setting it up for 35-40psi and blowing up the charger in no time..... yet here we stand not able to hit 20.

TyCorr said:
Maybe those two heavier fueling tunes are raping the charger. Overfueled, oversped.

Could be.... though still have never seen more than 17psi on either the map reading or the edge CTS with a pressure sensor in line.

Derek@Vision Diesel · Jun 14, 2013

Main reason I believe the filters are doing their job is the filter minder has not once been sucked in...

Maybe that isn't a reliable source, but it seems to work pretty good on other vehicles

POWER-STRUCK · Jun 14, 2013

did you check the baro sensor? some 99's have them under the steering column

Arisley · Jun 14, 2013

Is there a rubber line between the filter and the turbo? If so, that could be collapsing. Might try running it with no filter see if that fixes the issue. If it does, you will know where you have to go.

bluedge8 · Jun 14, 2013

I would def, test it with open charger and see what happens. Is there something that could be wrong with the MAP system even though your readings seem right?

Derek@Vision Diesel · Jun 14, 2013

I wont lie... you guys were entirely right.

The intake tube didnt ever cross my mind. even without filters in it, it will suck the tube closed. I went open turbo and this van straight gets it on.

Time to make up a custom intake!

Sorry for wasting peoples time, stupid van intake!

TyCorr · Jun 14, 2013

Time for solid 4" pipe.

bluedge8 · Jun 14, 2013

glad you got it figured out

mandkole · Jun 15, 2013

sweet...

Arisley · Jun 15, 2013

Derek@Vision Diesel said:
I wont lie... you guys were entirely right.

The intake tube didnt ever cross my mind. even without filters in it, it will suck the tube closed. I went open turbo and this van straight gets it on.

Time to make up a custom intake!

Sorry for wasting peoples time, stupid van intake!

No waste of time, that's what this forum is for. Glad it was something simple.