Boost Dumping Prematurely Help!!!!!!

[travislaw]

I have a 96 Eclipse GS-T. My car is dumping boost into the exhaust at 4,000 RPMS. It is also hitting full boost on the stock boost gauge at 4,000 RPMS also. I have replaced the wastegate actuator and still have the same issue. Could my problem be the Turbo Chager Wastgate Solenoid? I had my car at the dealership and paid $700 for them to tell me to return my intercooler piping to stock and take off the 1st Gen BOV. So I returned it to stock and bought a new 2nd gen bov because my old one was broken. It was boosting better, but the problem was now happening at 4,000 RPMS instead of when I started boosting. It is like going from turbo acceleration to geo metro acceleration as soon as I hit 4,000 RPMS. Here is a list of what I have done this year.

• New 255 LPH Fuel Pump as of 10/2005.
• New Starter as of 10/2005.
• New ECM (The Cars Computer) 09/2005.
• New Catback Exhaust 09/2005.
• New Rebuilt Engine 02/2005.
• New Rebuilt Turbo 02/2005.
• New Stage 3 Racing Clutch 02/2005.
• Custom Metal Blow Off Valve Piping, works with 1st gen bov 08/2005.
• Cold Air Intake.
• New Hoses, Plugs (NGK), Wires 02/2005.
• New Cross Drilled and Slotted Rotors 09/2005.
• New Premium Brake Pads 09/2005.
• New HKS Turbo Timer 03/2005.
• New Window Tint 08/2005.
• Entire Intake and fuel system cleaned 08/2005.
• Mobil 1 Synthetic changed every 2,000 miles.

Any advice would be greatly appreciated.

 

[DSM90AWD]

It is also hitting full boost on the stock boost gauge at 4,000 RPMS also. I have replaced the wastegate actuator and still have the same issue

A stock boost gauge predicts boost based on read airflow. (i.e. does not directly read boost). Get an aftermarket gauge and post back your real boost level.

It was boosting better, but the problem was now happening at 4,000 RPMS instead of when I started boosting. It is like going from turbo acceleration to geo metro acceleration as soon as I hit 4,000 RPMS

Sounds like a classic case of "Fuel Cut" (i.e. ECU reads more airflow that the limit and cuts fuel to safeguard the engine). May want to check for boost leaks btw the turbo and intake.

I do see that the 255 Fuel pump on the stock FPR might cause an over rich condition (will overrun the FPR and raise fuel pressure), but should not cause a serious cut in power at 4K. How do your plugs look?

 

[ddavisaf]

Run a boost leak test 20 psi for 30 seconds or more.
Check and make sure you're running NGK BPR6ES plugs gapped at .028"
Make sure your wires are not damaged or 10 years old
Get an aftermarket boost gauge
Either get an aftermarket fuel pressure regulartor, or put a 190lph fuel pump in.

And I think that covers it...

 

[travislaw]

A stock boost gauge predicts boost based on read airflow. (i.e. does not directly read boost). Get an aftermarket gauge and post back your real boost level.

Sounds like a classic case of "Fuel Cut" (i.e. ECU reads more airflow that the limit and cuts fuel to safeguard the engine). May want to check for boost leaks btw the turbo and intake.

I do see that the 255 Fuel pump on the stock FPR might cause an over rich condition (will overrun the FPR and raise fuel pressure), but should not cause a serious cut in power at 4K. How do your plugs look?

My Plugs look good. They are all the same color, although I don't recall what the color was.

 

[travislaw]

Run a boost leak test 20 psi for 30 seconds or more.
Check and make sure you're running NGK BPR6ES plugs gapped at .028"
Make sure your wires are not damaged or 10 years old
Get an aftermarket boost gauge
Either get an aftermarket fuel pressure regulartor, or put a 190lph fuel pump in.

And I think that covers it...

I have an Autometer Boost Gauge. Where do I tie it into in the turbo system?

 

[DSM90AWD]

I have an Autometer Boost Gauge. Where do I tie it into in the turbo system?

The best place is to tee it into the vaccume line btw the FPR "module" and intake. This will read true boost pressure at the intake manifold

 

[TJGoSurf]

The best place is to tee it into the vaccume line btw the FPR "module" and intake. This will read true boost pressure at the intake manifold

I have issues with this, if you could show me something more than someones opinion on why it is ran there. All I have heard is, "thats the way it is".

Next all those mods and not one boost gauge?

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[DSM90AWD]

I have issues with this, if you could show me something more than someones opinion on why it is ran there. All I have heard is, "thats the way it is".

I originally got these instructions from Buschur when I purchased my first boost gauge 10years ago (VDO) : http://www.vfaq.com/mods/wayback/BradBauer/gauges/boost.html

Rationale is that you want to read pressure at the manifold as that is ultimately what your engine is consuming and is likely several psi less than the turbo outlet due to pressure loss from the intercooler, piping, throttle plate and any boost leaks.

Mitsubishi also chose this location as the vac/boost feed for the stock rising rate FPR, so it reasonable to think many engineers that know much more about DSMs than you/I will ever know figured that was an accurate place to tap for a boost signal

 

[oldman]

I have issues with this, if you could show me something more than someones opinion on why it is ran there. All I have heard is, "thats the way it is".

What would then be your suggestion and why?

 

[TJGoSurf]

What would then be your suggestion and why?

I would suggest at the manifold. Its simple and it works. 1 line running to a gauge.

While that was a nice write up, I'm still not convinced that it is the best location. Even in the link it says the consensus of club DSM. Thats still opinions.

 

[oldman]

I would suggest at the manifold. Its simple and it works. 1 line running to a gauge.

While that was a nice write up, I'm still not convinced that it is the best location.

The fps/fpr line that John suggested is from the intake manifold, the reason it's the best location is mostly because it's closest to the firewall which allows the shortest hose route possible, mostly.

 

[DSM90AWD]

Even in the link it says the consensus of club DSM. Thats still opinions.

Club DSM = Thousands of DSM owners opinions from 1990-2002.

I would suggest at the manifold. Its simple and it works. 1 line running to a gauge.

And that is different from my recommendation how

I have an opinion that you should stay out of technical threads until you learn more about DSMs.

And fill out your vehicle profile