fbgh2o

So after checking everything, I decided to have my mechanic replace the O2 sensor and check the fuel pressure.

New O2 sensor is showing a full rich condition (0.8V).

Fuel pressure at the rail is 2.7 bar at idle (3.2 bar without vacuum) - which are within spec I believe.

I am now truly stumped for ideas.... thoughts are welcome.

(John, no need to answer here - I have emailed you separately - just sharing for posterity).

choinga

I'm hoping that I'm not in the same boat. I bought a ZT2 and ZR2 from John today to replace my narrowband to get a better idea of where I'm at. Since my MAF install my narrowband is all over the place (mostly on the rich side) compared to the previous setup (Vitesse AFM + Accuboost). I'm going to take it to my local Porsche shop next week so they can weld in a bung for me and I can get this thing installed and see what's really going on.

I bought a new O2 sensor as well - I'm going to get that installed when I have time...probably this weekend and see if that helps me any... It's so ga'damn hot outside right now the thought of sitting underneath a car with a hot engine doesn't sound all that pleasing...

You don't have a fuel pressure gauge on your rail??

Keep us posted!!

fast951

Fergus, I already replied. Since the car ran fine for a 1000 miles, the injectors, MAF and software did not change. It started running rich after something took place. Go back and see what got touched or what got changed!

You have a 3bar FPR. Why is it reading 3.2bar? Is the gauge a bit off?

Did you pressure test the intake?

fbgh2o

Factory rail... so no.

fast951

Ken, Didn't you have a issue with a hose clamp at the TB? Just changing the clamp, changed the behavior of the car. Time to pressure test the intake system!

TurboTommy

In your first post you mentioned something about your wideband not working correctly. Do you have it installed and wired up? Is it wired into the DME or stand alone? Why is it not working?
Are you running rich at all throttle positions?

fbgh2o

It is installed and wired up stand alone... It just does not read right... The gauge remains pegged at 18:1 almost all of the time, while data logging shows that it starts off measuring at 16:1 and over the course of 90 secs after start up drops to 6:1 and stabilizes there... I am getting 5V in free air so I think the sensor itself is working fine. Something else is not right...

Given this I cannot tell you where I am rich, except at idle...

TurboTommy

Call the Innovate tech line; they will be able to help with your wideband. You need to have that fixed as it will give you valuble information that you should always have.
If you haven't already done so, you absolutely need to pressure test the entire intake; again valuble information will be gained when knowing where any leaks are. Most issues that I have ever had were found out when I pressurized the intake, One thing you could check, for example, is leaks around the recirculation valve. I had a bad vacuum connection there once, and definitely rich idle or at very low engine loads.

choinga

where is that recirc valve, Tommy?

fbgh2o

You mean like this

I found a leak near or in the ISV - am installing a new one tomorrow. Also found one at the blow off valve (recirc?) hose where it connects to the intercooler pipe. Otherwise all good.

87_951_Turbo

i had the same problem soon after i bought my car! check your fuel pressure. Mine was tacked at like 90 psi.

fbgh2o

See post 16... it's okay.

DrZ1

If you have the innovate, you can wire one of the outputs to the PB, John already fiqured the values to plug in. My A/f gauge is not real accurate but the Innovate software and the the PB values are good. So you could check your A/f by laptop and Vitesse softwar.

PS. John wiring up the DTA in the track car today. Engine was dropped in yesterday. Hope to have it running in a month. WIll get with you after that to finish setting up the PB.

Steve

TurboTommy

You're installing a new ISV;
Another words you're taking off the intake manifold? Replace hoses while you're there (probably did it already).
Make sure you re-pressure test the intake afterwards; not the the first time a re and re produces new leaks.

fbgh2o

So I finally got the car running again...(before I snapped the head off the coolant bleeder screw)

After all the diagnosis and replacement of the O2 sensor, which did not yield any overt issues, did the following:

• Recleaned all of the grounds (pulled the intake and used a Dremel on the ones on the bell housing that were coated in coolant residue (see below)
• Installed my IceShark battery cable kit
• Replaced a leaky ISV
• Replaced the leaking heater valve
• Installed new intake gaskets (had the intake off)
• Installed new spark plugs
• Installed my MBC (a while in there project)

Car still seems rich (smell test, but I wonder how much of this is due to the fact that I do not have a catalytic converter), and the wideband is simply not believable (a new LC-1 is coming) as it reads 8:1 at idle (no clouds of black smoke though and not an overpowering smell) and bounces continuously between 10 and 16 while at constant speeds...At least now it registers something other than 18:1.

As an experiment, I turned the FQS to position 2 (-5% with the Vitesse chip), given that the fuel pressure was showing 3.2 bar when it was tested. Idle (at start up) is not as smooth as before, but the car seem less rich....Interestingly the wideband now bounces between 13 and 18 (seemingly an indication of a leaner mixture), but still reads 8:1 at idle....

John's support has been awesome throughout.... Somehow I see a Piggy-back in my future