The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support STM Tuned
Please Support STM Tuned

2G Running rich!!

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Allman

Probationary Member
18
1
Jul 12, 2014
Seymour, Indiana
Hello ladies and gents. I just picked up a 95 Talon TSI AWD. The car is running really rich. Enough so that the car blows black smoke while driving. Running a datalog on the car with my OBD2 tool shows both front and rear O2 sensors are flat lined at .1v at all times (idle, cruise, wot). When letting off the throttle to slow down the front O2 will raise to .4v for a few seconds and then drop straight back down. All fuel trims are pegged at 12% and 24%. Also when driving, when I push in the clutch from under any boost pressure at all the car will overload with fuel and stall out. I checked the resistance of the front O2 sensor and reads 23ohms. Checked the wiring to make sure the cruise control and front O2 plugs were not reversed. Checked wiring to make sure it is seeing voltage also and I get battery voltage at the connector. This weekend I will be doing a boost leak test and a rear O2 simulator.

The car is all stock except for 100mm crank, eagle rods, wiseco 9:1 pistons, intercooler, and 3in turbo back exhaust. The BOV is still recirculating and working correctly. I have searched the forums and done multiple checks on the car and nothing yet. Any help would be appreciated.
 
I traded for it. No CEL but I pulled p0170 fuel trim (bank 1)
p0136 O2 sensor circuit malfunction (b1s2)
p0141 O2 heater circuit (b1s2)
p0443 evap purge control.
Other than that I have not had a change to check the pump and don't have a tool for checking fuel pressure yet. Just got moved in my house on Wednesday so I am bouncing between the 2 right now. The guy told me everything else was stock on it. It hits fuel cut at 4,000 rpm also
 
The CEL should be on with those codes is it even working? (the bulb in the cluster) so yeah pretty much your rear o2 is junk or you have some big exhaust leak. I would recommend no expert here just advice do boost leak test mostly if you are on stock MAF do yourself a favor and check the injectors just to make sure. Replace the rear o2 or check if it's even plugged in! Don't worry about the evap for now.
 
just got home from work. removed the driver seat and the rear O2 has been cut and spliced -_- since it doean't have a cat anymore should I do the rear O2 sensor simulator mod? Or get an extended piece for the O2 to sit out of the pipe all the way? The injectors were black with a steel body. I read somewhere different colored injectors mean different sizes. I will look for that post also. Boost leak test is getting done on wednesday when I am off work. Thanks for your response btw!
 
pink - 240cc - (1g 2.0Ln/t)
tan - 390cc - (1g turbo auto)
blue - 450cc - (1g turbo m/t, Galant VR4)
black - 450cc - (2g turbo)
yellow - 510cc - (evo 1-3)
pink - 560cc - (evo 7-9)

I found this in some other post so it looks like you have 450cc injectors. What psi are you at? I was hitting fuel cut before because of my stock injectors man, after I got bigger ones and did a small tune it never happened again.
 
Thanks for the reply and info! I was going to find that tonight but have been busy with house work :/
update:
I replaced front O2 and made a simulator for the rear. runs leaner and no more fuel cut but it's still to rich. it also dies when pushing in the clutch from anything above 5in-hg (vacuum). i am running 12 psi. i found the bov opens at idle. i think they are suppose to remain closed at idle correct? Tonight I am going to make a boost leak tester and check it. it shows 12psi is getting to the manifold but would a manifold gasket cause pressure loss without the boost gauge showing any different? It still blows black smoke out the tail pipe while driving.
 
Update:
Made a boost leak tester and found the system wouldn't even build over 1psi 0_o So far all the piping and BOV checks ok at 1psi but the throttle body and elbow to throttle body were leaking like crazy. I have ordered a new gasket set and will be checking the throttle shaft seals as well and retesting. Also I pressurized the cooling system and found a few small coolant leaks. I will update once I get the new parts installed and retested.
 
That is what I thought. I will have to look into that.

Update:
Replaced tb elbow gasket and BISS oring. BISS still leaks :( but boost leak tested again and found pressure loss at 4-6psi. Throttle body shaft seals leaking. Have been reading up on 1g tb to 2g manifolds as they are larger.
 
I ended up picking up one for 30 bucks at the junk yard. 63mm inlet and 60mm outlet tb. Cleaned up some of the car, ported the manifold, replaced a few small hoses and now it hold some boost. Found the brake booster leaks some but once you touch the pedal it stops. Took it for a test drive and it runs way better. Haven't had a chance to have anyone follow me to check for black smoke. Oh also cleaned the plugs and regapped them.
 
Been a while since i have been on here. Fix the boost leak. Replaced the tb and was ok til 10 psi. Added 2 brake booster check valves in the booster vacuum line off of a honda and no more boost leaks. Now the car is on 1000cc injectors and evo 8 ecu. Soon to be e85 and hx35 t3 twin scroll.
 
Wow it has been almost a year since I have updated this. Found the car had a Walbro 255, blown out FPR. Replaced with an Adjustable fuel lab regulator. ran great for a while but still over fueled a lot. Started dialing in the MAF Scaling and got it to were it was no longer over fueling. Ended up lifting the head and stretching the head studs. Blew #2 and 3 head gasket. Tore the engine apart and the rod bearings were trashed. Scored the crank and rods up. This was all done mid summer. Found it to have a cheap ebay clutch in it. It was slipping at 24PSI and it would not hold a launch at all. So I will be building an engine myself this time. The engine had the work done before I got the car. I am currently redoing the suspension, brakes, interior, converting to a manual rack, and will be doing a tubular front end, solid rear axle, cage, and will be building a 6 bolt all in due time.
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top