EVOscan Can't boost past 5 psi, seems tune related

[eclipsh]

I'm pulling my hair out. I can't seem to build past 5 psi of boost on my car. It appears to be load related as I can't boost to as high a PSI when I'm pulling a hill at lower RPMs (3k). Car has a 2.4 @ 9:1 CR with an HX35. I'm running an Evo 8 ECU with the stock 2g MAF.

I've tried:

rebuilding the turbo
increasing the wastegate spring pressure
disconnecting the line from the wastegate opening port
switching from a 4 port BCS system to a 3 port
boost leak tests
Changing duty cycles for the wastegate and target boost pressures.

I think I've got an issue in how I have the ECU set up. Can someone knowledgeable please take a look at my ECU file and some of my logs to see


1). Any boost, vac, or exhaust leaks?
Nope.

2). Verified mechanical timing?
5 deg BTDC

3). Verified base timing?

Yup

4). Ignition system
COP or Stock Coil: Stock
Wire brand and Age: New NGK
Spark Plug brand, type and Gap: NGK BPR7ES .028

5). Motor health (Compression Test)
New build, 600 miles on motor. Don't remember numbers but compression is good.

6). Performed basic throttle body adjustments?
Yup.

7). Compression ratio
2.4 @ 9:1

8). Any known bad sensors or brittle wiring?
No

9). Any DTC/CEL codes?
No

10). Electrical system
Yup, it has one.

11). Base fuel pressure and injector values
Base Fuel Pressure: Stock
Injector Size (cc/min): FIC 750

12). Properly calibrated and configured wideband sensor
Sensor Brand: Innovate LC-2
Calibration Date: About 3 weeks ago.

13). Type of fuel
Type: 91 Octane
Percent of Ethanol: Unknown

 

[eclipsh]

Turns out I have a big boost leak in my brake booster. Oops.

 

[eclipsh]

Well I fixed the brake booster leak. I didn't know the OEM line going to it had the check valve internally so I threw one in the line I used.

I'm still getting the same problem. I've tried changing my WGDC table to all 0 and 100 and nothing changes. I've scaled my injectors up and down. The AFR changes but I'm still stuck at the same boost.

I did a boost leak test at the TB and I do drop off fairly quickly but on a cold engine I don't find that surprising. I was venting out the valve cover which could easily be coming from rings, valve guides and an OEM PCV valve. The flow wasn't crazy fast.

If it is a mechanical issue I'm stumped. I've got new plugs and wires. Maybe the coil is blowing out or the fuel pump is weak but the WBO2 data doesn't support that.

So I'm wondering if something in my BIN file is screwy. can someone please take a look?

 

[pauleyman]

Well I fixed the brake booster leak. I didn't know the OEM line going to it had the check valve internally so I threw one in the line I used.

I'm still getting the same problem. I've tried changing my WGDC table to all 0 and 100 and nothing changes. I've scaled my injectors up and down. The AFR changes but I'm still stuck at the same boost.

I did a boost leak test at the TB and I do drop off fairly quickly but on a cold engine I don't find that surprising. I was venting out the valve cover which could easily be coming from rings, valve guides and an OEM PCV valve. The flow wasn't crazy fast.

If it is a mechanical issue I'm stumped. I've got new plugs and wires. Maybe the coil is blowing out or the fuel pump is weak but the WBO2 data doesn't support that.

So I'm wondering if something in my BIN file is screwy. can someone please take a look?

At the tb? Why arent you testing the entire thing?

 

[Dhan]

It still sounds like a giant vacuum or boost leak.

I would pressurize the entire intake tract and look/listen for leaks. Attach your boost leak tester right at the turbo inlet so the intercooler and all the piping is pressurized. Use the old soapy water in a spray bottle technique and search for bubbles.

The other day my car would suddenly not boost past 9psi. I could give it full throttle and it would just peg at 9psi to redline. I'm on speed density so I drove it home and sure enough, big boost leak where a coupler had just blown off.

 

[eclipsh]

I tested at the turbo inlet previous to rebuilding it. I'll try testing there again and see. I'll also test right after the outlet.

 

[boostdawd]

Place a boost leak tester on the inlet of your turbo as that will pressurize the entire system so u don't have to do it in stages. Pressurize it to more than 10psi of your target boost level. What are u using to test??

 

[eclipsh]

The turbo inlet is 4" so using a test fitting there that doesn't slip out under pressure is tough. The 2" line just past it is much easier. I'm using abs pipe caps with a Schroeder valve threaded in and a 100 psig analog gauge.

I did soapy bubble testing when I pressurized from the TB. It led to me putting zip ties on all my vacuum lines. I'll do another test when I get home form work tonight and see what I find.

 

[boostdawd]

Look up the info on diesel sites about the blt for that tester. I remember a few years ago I made one for my Cummins and was able to keep pressure til 45psi.

 

[Chumpaumpalumpa]

Recheck for exhaust leaks or cracked housing

 

[eclipsh]

I found a big leak at one t bolt clamp that wasn't tight enough on the intercooler lines. My 4" test cap was leaking so I got parts for a better setup and will try again tonight.

 

[eclipsh]

Boost leaks are gone. Now it stutters and won't build past 3 psig. I'll do some logging this weekend and see if I'm just running too lean/rich now.

I haven't noticed any exhaust leaks or cracks. The BEP housing is new as is the tubular O2 housing. It is chinabay but I sanded all the flanges to be flat and perpendicular so I don't see that being an issue.

 

[boostdawd]

What kind of plugs are u running?

 

[boostdawd]

Try to load up a log so we can see what's going on

 

[eclipsh]

All I have right now is the logs before the boost leak was fixed. I'm attaching one. I was going a little down hill at the time. It started stuttering hard at ~5 psi right where the AFR starts leaning out. Again, that was with the boost leak. I can't say the AFR is still doing the same but it feels identical just at lower boost now.

I'm running NGK BBR7ES plugs.

My WBO2 is in the rear O2 hole if that matters. I've got the O2 simulator turned on with the WBO2 data going in through the NB02 wire.

 

[boostdawd]

Having the wb at the rear O2 will not give u the best and most accurate afr. Most put it in the front O2 housing for better throttle response/reading. I would recommend using NGK BR7ES plugs gapped a little tighter say about .25 or so if your running e85. What fuel are u using?

 

[boostdawd]

Looking at that log file your target afr and actual afr are wayyyy off. It's leaning out real bad throughout the pull. Either a real bad boost leak still or adjustable fuel pressure regulator. I'm confident its all tied together and the tune as well.

 

[eclipsh]

The previous log was with all the boost leaks. The log attached to this post is with all the boost leaks fixed except a tiny one at the banjo fittings for my WG. I'll get that fixed today if I can find copper washers the right size.

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You can see where I lifted on the throttle in the first log. That is where the car started to stutter bad. It has a pace like a drum roll, the car lurches and won't build any more boost if I stay on throttle or let off.

The second log is just me cruising on my way to work so I could watch fuel trims.

I dropped the car off today to have an O2 bung welded onto the downpipe right at the bend. Should be nice placement.

 

[eclipsh]

It was a bad coil pack. I swapped to a spare on a hunch that I was getting spark blowout. I hit 24 pisg on my first pull and had to back off. Holy @#$% this thing spools quick now. Time to turn the boost down a little bit and go tune!

 

[boostdawd]

Nice! Glad u got it all figured out!