Hey Everybody,

It has been quite some time since my last post. Hopefully, a few of the long term members will still recognize my car from my signature.

I have a 1996 GS eclipse with built motor (bottom end), a Hahn Racecraft turbo kit (running about 10 psi), and a Hahn Racecraft Portfueler module. Recently, the car has developed a low vacuum condition (vacuum of 10) which is causing the car to have a rough idle. The check engine light has not come on yet. Here are the steps that I have taken to try to diagnose the problem:

Compression Test (on 8.6:1 motor): Better than 190 on all cylinders
Homemade Boost Leak Tester: Only builds 4 psi (used a tire compressor)

Here's my question. My car does not run an EGR block off kit as I need to pass an emission inspection in New Jersey. However, when performing the boost leak test, I can feel air coming out from the vents of the EGR valve (metal valve located on the driver’s side of the head). Is this normal operation of the EGR valve? Should the valve vent when positive pressure is applied or do I have a faulty or stuck open valve?

The final observation that I had is that when the car is idling rough the exhaust gas temperature is up from the normal of 900 degrees to about 1000 degrees. This seems to lead me to believe that the valve is stuck open and that the exhaust gases are being constantly recirculated.

Please advise or guide me in a better direction. As always, I appreciate the help!

--Kurt

There should be no air leak to atmosphere through the EGR valve. That valve is controlled by air pressure (vacuum) and requires a diaphram to do so. The EGR solenoid valve controls engine vacuum to the EGR valve. When vaccum is applied to the EGR valve, it opens and allows exhaust gas to travel to the intake manifold. When the engine is off, the EGR solenoid valve is open. That lets your pressurized test air travel straight to the EGR valve. If the diaphram was in tact, the EGR valve would close hard and there would be no air leak to atmosphere. If the diaphram was broken, you might hear an air leak to atmophere. When the engine is running, the broken diaphram would prevent the EGR valve from opening. If your EGR valve is not responding when the ECU tells it to, that might result in rough operation. The ECU might open the IAC a little to compensate for the missing EGR flow. This might result in some rough running at low load. Opening the IAC would give you low vacuum as well (like opening the throttle). The ECU does not normally run the EGR at idle, but it might be testing the EGR function. Also, a properly functioning EGR system is supposed to reduce EGTs slightly. So, the lack of EGR would cause the opposite. Or, the ECU is running a slightly high idle to keep the engine running. That extra RPM cold increase your EGT. Anyway, I would replace the metal EGR valve.

Corbin
'95 ESI-T

Now with more power and fewer leaks



Humble servant of the Wiki

my egr did the same and i removed it but it may have just been bad