The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support Rix Racing
Please Support STM Tuned

2G 2G over boosting and break up at high Rpm

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Connor Wilke

Probationary Member
28
2
Mar 15, 2019
Hinsdale, Illinois
Hello, This is my first post. And I’ve tried looking up my exact issues and had no luck finding anything yet

Just got a new laptop so I don’t have any logs yet
•Brand new plug wires
•Brand new NGk BPR6es gapped to .020
•Coil packs are in good condition
•Have 280 cams and have great vacuum about -10
•No boost leaks
•510cc yellow cap injectors
•43psi fuel pressure

My issue with the car currently is that when WOT the car pulls good until about 6000rpm and starts breaking up in full boost- second part to this is that it’s operating off stock wastegate spring pressure. Should be making around 12psi but I’m seeing 15psi and up
Had issues with the tune before where it would start breaking up around 4500rpm but when I went back to a stock tune all the break up went away but now it breaks up and overboosts at higher rpm.

I ordered bpr8es because I was going to start running higher boost pressure but now this break up problem has me confused
 
First things first, for break up: you are running BPR6ES. You need to be running BR6ES. Regardless how how cold the plug, you dont want that projected insulator. I had the same issue and my tuner recommended swapping the plugs to not protruding and immediately fixed the issue.

As for overboosting: I see you are running a 16g so, boost creep is usually caused by the internal waste gate not allowing enough exhaust to escape the turbo. For lack of better terms, port the internal wastegate flap a bit. There are plenty of threads on the proper way to do this.
 
First things first, for break up: you are running BPR6ES. You need to be running BR6ES. Regardless how how cold the plug, you dont want that projected insulator. I had the same issue and my tuner recommended swapping the plugs to not protruding and immediately fixed the issue.

As for overboosting: I see you are running a 16g so, boost creep is usually caused by the internal waste gate not allowing enough exhaust to escape the turbo. For lack of better terms, port the internal wastegate flap a bit. There are plenty of threads on the proper way to do this.

I will give that a shot. Because I was told to run the ngk bpr plugs. I will order some BRs and see if that fixes my issue. Because now I’m not making full boost and break up is getting worse again
 
I will give that a shot. Because I was told to run the ngk bpr plugs. I will order some BRs and see if that fixes my issue. Because now I’m not making full boost and break up is getting worse again
Dial it down a bit. If you haven't changed anything, no need in checking to see if it magically went away LOL. Make sure the plugs are gapped correctly and throw in a non protruding plug. Easy fix.
 
Dial it down a bit. If you haven't changed anything, no need in checking to see if it magically went away LOL. Make sure the plugs are gapped correctly and throw in a non protruding plug. Easy fix.
I am waiting for my plugs to come in. But when I change them should my boost levels go back up too? I’m just curious because I only make 5psi at wot
 
Oh boy. I thought you said 15 earlier. It may be other issues. 5psi is very little boost to be having breakup. Do you have a log that you could post up?
I just received my new br8es and put those in. Now the car breaks up at 4K rpm. I will try and get a log before I have work, but my logs are off evoscan so not sure how hard it’s going to be posting them
 
i took the car for a test drive today after fixing some boost leaks i found. car idles okay, but again its breaking up at 4k Rpm and will barely making 6psi of boost.
I have upgraded to denso 660CC injectors and bought new plug wire and replaced the coil packs.

Evo Scan Log should be attached to this. could someone take a look at it and tell me if you see anything that might cause the break up or thing i should change.
 

Attachments

  • EvoScanDataLog TestDrive Break up at 4kRPM only 5psi boost.csv
    309.7 KB · Views: 34
i took the car for a test drive today after fixing some boost leaks i found. car idles okay, but again its breaking up at 4k Rpm and will barely making 6psi of boost.
I have upgraded to denso 660CC injectors and bought new plug wire and replaced the coil packs.

Evo Scan Log should be attached to this. could someone take a look at it and tell me if you see anything that might cause the break up or thing i should change.
It might be on my end, but i can't seem to bring up your picture.
 
Probably help if i wasn't trying to do it with an outdated phone LOL. Did you boost leak test while the motor was warm? I usually have had some hidden leaks due to testing it cold. Kind of goes without saying but did you put in new injector seals with the replacement injectors? If you can see your fuel pressure make sure it rises at a 1 to 1 ratio with boost as it comes on. If it isn't you probably have escaping fuel pressure causing the breakup. I had a similar issue recently and it was the high preasure hose coming off the fuel pump hanger. To me your issue sounds like a boost leak or fuel delivery issue or both.
 
Try necking down the gap on the plugs to .20.
I have to run BR8ES NGK plugs and have them gapped at .18 but I have 40 lbs of boost that trys to blow it out, but it doesn't when I run the gaps really close.
 
Probably help if i wasn't trying to do it with an outdated phone LOL. Did you boost leak test while the motor was warm? I usually have had some hidden leaks due to testing it cold. Kind of goes without saying but did you put in new injector seals with the replacement injectors? If you can see your fuel pressure make sure it rises at a 1 to 1 ratio with boost as it comes on. If it isn't you probably have escaping fuel pressure causing the breakup. I had a similar issue recently and it was the high preasure hose coming off the fuel pump hanger. To me your issue sounds like a boost leak or fuel delivery issue or both.
The turbo has quite a bit of shaft play, and I just found a tiny leak at the throttle body gasket again. My Fpr is set to 43psi and holds there until throttle is open and then is lowers a bit to about 40

Try necking down the gap on the plugs to .20.
I have to run BR8ES NGK plugs and have them gapped at .18 but I have 40 lbs of boost that trys to blow it out, but it doesn't when I run the gaps really close.
I’m still trying to fix all leak, and I already had them gapped to .17 and still broke up pretty bad. But why I can’t make more than 5psi is troubling me.
 
Last edited by a moderator:
If you are only getting to 5 psi, I would think you could HEAR air escaping at any major leak. I know you don't have a way to see what your AFR's are at when it occurs. If you had a wideband O2 sensor and gauge, that would tell us more about the mixture, whether it is lean or rich. Double check ALL connections in the turbo track, all couplers, wastegate, blow of valve (recirculating valve as some call it). There is a major leak in it somewhere.
 
If you are only getting to 5 psi, I would think you could HEAR air escaping at any major leak. I know you don't have a way to see what your AFR's are at when it occurs. If you had a wideband O2 sensor and gauge, that would tell us more about the mixture, whether it is lean or rich. Double check ALL connections in the turbo track, all couplers, wastegate, blow of valve (recirculating valve as some call it). There is a major leak in it somewhere.

I was leaking very badly from my Bov and throttle body. the boost leaks are now all taken ccare of.
After finishing every up on the car it was able to make full boost with no break up. i changed a few numbers for the injectors and it broke up again so now i am ordering a AFR kit tomorrow finally.

Could be a wastegate issue, or boost control solnoid. Are your throttle body shaft seals leaking or maybe the biss screw?
No i actaully just rebuilt my throttle body because of both issues a month or so ago. im not running my wastegate solinoid though. i have the line from the wastegate going to my intercool piping.
 
Last edited by a moderator:
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top