996-LO

Setup is as follows:
2002 Porsche 996 3.6L
Naturally Aspirated
K&N intake
Equal length headers, short center exit exhaust
Stock DME/Ecu

I feel like there is a Major issue going on here. The air/fuels are pegged at 10.0 on the dyno which could mean they are actually lower.

Any suggestions will help i have not gone through every wire on this car yet but i will if i have to lol.

Just a background this car was built from a bare shell. I will answer any questions to the best of my ability as this is new for me.

Video and pics

Ahsai

What is that 1 fault in the DME?

rglbegl

If it is a track car only, I would either flash the ECU or go stand alone.

Once the AFR is correct (Closer to Stoich) you should see very fair gains in power.

996-LO

i was not able to access. the scanner stated "Can timed out" when we attempted to access the code

996-LO

i understand that however if there is an intermittent electrical issue a tune would not solve much. I did not build this car so my knowledge in that aspect is limited. There may be a break in the wiring i cannot see. I am slowly going to chek the continuity with my volt meter as time goes on. I just want to get feedback from neone. Sometimes you never know someone may have had a similar issue and can help you solve quicker. Right now im basically trying to learn what wire/sensor/malfunction would cause the Ecu to peg it rich.

Ahsai

The fastest way will be to hook up Durametric or even a generic OBDII scanner to the OBDII port, assuming there's one. Duramteric will tell you all the parameters (e.g., MAF reading, coolant temp, fuel trim, etc.) you need to diagnose this.

rglbegl

Stupid question, but is the ECU from that exact engine?

996-LO

i do not have a scanner i just got lucky at the dyno. also i am not 100% sure about the Ecu being for the engine.

rglbegl

Make sure the ECU is for that exact engine. For example; The automatics and manuals will be different.

Flat6 Innovations

When these engines see upgrades they typically richen up, not lean out. The power you are making is what I consider "stock" for a 3.5 on my dynojet from an engine that has nothing done to it.

What are the fuel trim values in TRA and FRA?

white out

check maf and o2's for a fault.
check to make sure there isn't a leak somewhere on the intake manifold.
check fuel pump performance
bench flow injectors

can you data log or see the map?
Does the computer have a stock tune or was it designed for a different set up?

996-LO

Well today seemed to be a good day. After much research and diligence last night we came across this thread from Renntech. http://www.renntech.org/forums/topic...l-air-mixture/

We learned of someone that had a similar problem with super rich mixtures and what a few suggestions were to remedy them. The one in particular that stood out for us was the addition of a Resistor of a certain OHM that could essentially trick the computer into running lean. This resistor would be added in between the #5 signal wire on the MAF plug (White/Dark blue color). There is no way anyone would believe that a simple $.05 cent resistor could make such a dramatic difference. Well we decided to take the plunge today and purchase these miracle resistors and give it a try. WE installed a 560 ohm 1/4 watt resistor. I dont have pictures at the moment. I will get them ASAP.

The difference is unexplainable.... lost for words is more like it. Our car would not even idle prior to this "mod" if you wanna call it that. Prior to the resistor, the fuel smell was so so concentrated that it would saturate the air and your clothes. Prior to the resistor, the dyno was the proof that we had a severe fuel dumping issue.

As of today it was what i would call a "miracle mod". The engine immediately started with barely one crank. The idle was incredibly stable. The revs were much smoother. The smell of fuel was almost completely gone. Smells like a usual de-catted car. Unbelievable more like it...

I dont expect to take any recognition for this i am just happy and truely humbled by this experience. We had an amazing team effort up to this point and never ever would we have thought a frikin $.05 cent resistor would be the answer. Wow....

Just as a precaution we did however schedule an immediate Dyno session and we purchased a large assortment of various OHM resistors to "fine tune" the A/F ratios to a safe range. I will get the results and all the info and share it as soon as i can. I am not crying victory here just yet however the overall difference today is good enough to call this a victory.

ltusler

No offense, but it seems to me that you just put a band aid on it not solved the real issue.

alpine003

I agree but if it's really just a race car and it works consistently and reliably, then it's really your call. I don't know if I wanna be gambling on an engine replacement down the line if something were to happen though...

Flat6 Innovations

Is think that the fuel trim was adding fuel (FRA) for a reason. The resistor might have worked, but an underlying condition is something I'd be concerned about.

What were the fuel trim values before and after the resistor?