Car Setup:

HRC Stage II (max 6 psi)
Vortech SFMU (hard spring 2.72 disk)
Autometer lunar series gauges
NGK 7e-11 plugs .032 gap

I know I posted quite a bit about this topic but I just want to be safe. I was out testing my car again this weekend before unhooking the fuel pressure gauge. Under WOT, I see max of 100 psi. Under half or three quarters down, I see about 80 - 90 psi. Here's my question. When I am at WOT, the autometer A/F guage is in the lean range. How can that be at 5/6 psi with 90 - 100 psi of fuel pressure? The A/F guage has the blinking LEDs (not digital) and works perfectly in closed loop - bounces back and forth between lean and rich so I know that I have made the right connections. As soon as I come off the gas, the meter is max rich (in the green). Is there a delay?

Reading the HRC instructions, it says 5 psi you should have over 80 psi of fuel pressure. At 9 psi you should have over 110. My numbers based on fuel pressure may be a bit rich but safe. Maybe I should go by the fuel pressure numbers instead of the guage (I know the autometer A/F is not a great tuning device but should give somewhat of an idea.)

I plan on removing the spark plug in cylinder #4 tomorrow to inspect whether the car is in fact running lean (white on plug) or rich (black on plug).

The motor sounds extremely solid under boost - it never skips a beat, no knock what so ever. This is why I am confused. Any input/suggestions would be great.

Thanks,
Kurt

Did you replace your fuel filter when you installed the turbo kit? Mine old one really bad! I would check that, and check to make sure you don't have a kink in any of the fuel lines.

I went out and retested my car. I don't think it could be the fuel filter since the car is not straining to pump fuel and the fuel pressure hangs steadily at 80 - 90 psi under boost. (I am assuming if it was a clogged filter the pump wouldn't be able to supply this high of a pressure steadily). Just my logic.

It seems to be working ok now. What I must have been doing is lifting slightly off the gas after boosting and then taking the reading. The gauge seems to be very dependent on how hard you are on the gas pedal. I went out again tonight to do some testing. I kept my foot in the throttle and looked at the gauge. It was hanging about 2-3 green bars in the rich from the stoichiometry bars.

It makes sense to me if you think about it. If you let off the gas the car wants to return back to an idle state and pumps less fuel. Just like when you are sitting in closed loop mode idling. It bounces to rich, ecu picks this up, stops delivering fuel until the car goes lean, and then delivers more fuel (gauge goes back to rich). So when I boost it now stays green while under throttle. It was just hard to watch all the gauges at once (seeing what boost I was running, the fuel pressure, and the air/fuel). I probably looked at this one last and by then I wasn't boosting (off the gas).

Btw, BoostedGS (I have a 96 GS :)), how many miles have you been boosting?


Thanks,
Kurt

Your A/F gauge will only read accurate at WOT. When the throttle isn't fully open, the gauge will just "cycle". I'm sure you are fine with the fuel pressures that you are running.

I have a 96 eclipse gs with a HRC stage 2. I had a similar issue. When I contacted Gary at Howell, he told me that the stock ECU will not adjust to different settings because the factory limits on the ECU are very strict. When I purchased the performance ECU http://www.visionimports.com/ECU.html it made all the difference. It also will save your turbo in the long run. If you live in an area with cold winters and hot summers like I do, you will need to adjust accordingly to enviormental factors. Hope this helps

What 'performance' ecu did you buy?

FWIW, my o2 gauge quit working in my car about a month ago and I don't think I'm even going to replace it. I'm tuning with egt's and timing - to me the o2's are irrelevant and the sensors resolution is not high enough to be meaningful. I may put in a wide band o2 over the winter, but we'll see.