6G Celicas Forums

Pretty new to the turbo world. Only mod is the Berk downpipe on otherwise bone stock 3rd gen engine, running 12psi according to my gauge. Runs, idles and goes just fine.....just smells rich to me, exhaust tip is a little on the dark side too. Is it normal behavior or what? where do I start my troubleshooting?

This post has been edited by schmooot: May 2, 2013 - 12:34 AM

Turbo cars by nature run rich to keep the combustion chambers cooler.

the 3rd gen is setup to run pretty lean till about 4k rpm, then gets quite rich, so if your doing alot of boosting, then yea, i would expect it to be rich, especially running stock boost.
if its running rich all the time, then that is not normal, i would start by checking the o2 sensor, since that controls closed loop a/f ratio for the most part (basicly anytime your not in boost)... vac leaks, or exhaust leaks around the o2 will also affect it as well.
also make sure the hose from the map sensor to the intake manifold has no cracks or leaks, and isnt being tapped into for anything. (the map sensor is a big part of how the engine controls fuel and timing, so you dont want to interfere with that hose at all, as it could affect timing and or afr.)

i suggest you get a wideband O2 sensor. the AEM UEGO is a very good unit. every turbo car should have one

ummm I feel foolish, I'm a good mechanic but very very new to FI. It just smells rich at idle...can't say I noticed anything when she goes...usually just trying to keep it on the road. My boost gauge is teed off of a line....don't know which one. It was right by the firewall, maybe at the turbo pressure sensor. I followed a how-to article somewhere...probably gt4oc or gt4ec or gt4dc.co.uk. Can't seem to find it again. Sadly I don't know what half the lines are for in that beast. Please educate me.


As for the wideband sensor. I believe I have a bung for it in my dp already, I just assumed it was for running some sort of aftermarket engine management thing, didn't really plan on doing much upgrading...can barely afford to just maintain. Do I just unplug my factory O2 and plug the harness into the wideband one in the other hole? Or is there much more to it than that?

just found this thread http://www.6gc.net/forums/index.php?showtopic=23139&hl=

Imma change my tee location and see what happens

A wideband o2 comes in a kit, you don't just buy the sensor. You need something that interprets the 5v signal, since the ecu gets a 1v reading from the stock narrowband o2 sensor, and cannot interpret the wideband signal.

Innovate MTX-L, AEM UEGO are both good options, and you can find them cheap brand new in eBay. I bought an innovate LC-1 for 168 and then an Innovate MTX-L for 160 on eBay and they're both legit. Most other places will want to charge you upwards of $200

I see, and what are the advantages of the wideband over the standard?

A wide band allows you to see your Air Fuel Ratio more precisely and with a fuel computer you can set up a fuel map to optimize for power and efficiency.

This post has been edited by Box: May 7, 2013 - 2:03 PM

These cars run on the rich side stock for sure. Mine usually smells fine at idle, inside of my exhaust is usually black. It runs really rich on boost though

Also, keep in mind that there is no secondary cat on these cars, so a swapped DP means no catalytic converter = smells terrible.

If you want to be on the safe side, like others have said, use a wideband to check AFRs......if you know someone who tunes they probably have a sniffer you could clip to the exhaust outlet.

I personally wouldn't worry about it though.....they are supposed to run rich stock.

Boost should be ~13psi in all gears except 1st (maybe 2nd as well....been a while since I've driven the GT4).

For the boost gauge, tee off of the blocked off port on the bottom and middle of the IM. DO NOT use the line the MAP sensor is reading from.

Nick

This post has been edited by texasnick: May 7, 2013 - 5:31 PM

Just checked and I am teed off this line here, well not exactly but down there roundabouts...

and I am boosting right around 12-13 in all gears
so that is all good.

What texasnick said about there being no cat now with the dp makes perfect sense.

I really don't want to mess with tuning so a wideband setup would only give me more things to bother with and spend money on...I think I will keep it as is and sleep soundly,

This post has been edited by schmooot: May 7, 2013 - 5:37 PM

does the car bog down under 4000 and cough and sputter? if so, and smells rich, then replace o2 sensor with new factory replacement

no bogging at all. I won't worry about it