I had my old vw tuned with an uncalibrated wbo2 sensor...it ran at 13.5:1 for about a year. The pistons looked fine, but were clean as could be, most likely from burning off anything in the chamber, lol. I always wondered why the turbo housing and manifold would glow yellow (like a post-it-note) when all my buddies would glow dark, beat red.

I never ran the motor hard for extended periods of time like I will in the miata. 30 minutes at 13.0:1 is a lot different than 11.8 seconds.

 

Explosions

 

13.5:1 isn't terrible. Don't the narrow band gauges go lean at 14.7:1? So he's above that...

 

yes and yes. You're right...time to leak it.

Wow running any motor under load at 15:0+ is scary to think about.


Couldn't he also be running so rich that its reading lean? If fuel gets on the sensor it shows lean. I bet this is the case if he's been driving it for a year. I forgot to change the enrichments on my car with the 550's (from the stockers) and it pegged lean when triggered.

 

This could also be the case.

 

just got back working on the car...your tip on the AFPR was EXACTLY the problem. In was completely WRONG from the instructions Stephanie sent ( thanks btw ). There was residual residue orange like fluid that was under the Begi FMU ( the ufo ) , i wiped it down and removed all the hoses to the FMU ( hard to pull out btw ) After reinserting the hoses in line with the instructions to the FMU.I took it out for a spin and now it no longer rides lean It shows rich when i floor it and it just " feels " better. Ride is more consistant in acceleration and it doesnt bog down anymore. I still need to tune it, but my Fuel pressure gauge hose is too short to bring it out to my front window to see when i drive Im gonna have to get a longer one now....but that the least of my problems

It just seems like the SOB of a mechanic just hooked it up by guessing where the hoses go w/out tellng me he didnt know how to connect them I even gave him the instructions that came with the turbo to help him..I should torch his shop...

Anyway, it seems that the FMU is working...its providing more fuel when I boost and the car definitly moves now. Its like i got it installed the first time....i cant believe it took me almost a year to do it...

thanks guys...

 

Now that im lookin at the pics before i disassemble it...it looks like he put the hose from the stock regulator and hooked it up to the OUT of the FMU...i can only imagine what that could of caused..and thats only have of the way he set it up...

 

Now turn it to 6psi.

 

I'd wait for a wideband before you tune to 6psi. most of us run anywhere from 11-12.5 (correct me if I'm wrong guys) for air fuel ratios, which means your narrow band is always going to show lean, which is why a lot of us have widebands.