Hey guys, i have a b20v setup in an EK coupe. Runnin on a crome chipped P28. Just did a fresh rebuild on the motor and no matter what map i put in it... for the first 5 seconds it will run fine 14.7-14.8 but after those 5 seconds it cycles through every number and color on my AEM wideband till it just pegs 10.0 and stays there. A previous basemap i had on the same exact motor before the rebuild (same specs) was running so lean that it was pinging yet when i put it on now, it does the same thing. PIG RICH. makes no sense. Double checked all sensors and grounds, just replaced the GM 3 bar map sensor maybe 2 months ago. 1000cc precision injectors with a oem honda resistor box. The setup was fine before i did the bearings, rings, oil pump, headgasket... your basic refresh. Anybody else been through something similar before? Any help is appreciated, thanks guys.

 

Did you pull the plugs or verify with another wideband that it is actually running rich and not just wbo2 issues?

 

Another thing to look into that I have seen a lot of people do is mess up their IAT sensors...

1. Check the color of the wires running to the intake air temperature sensor. (Usually green & red wires)
2. Generally when you accidentally plug in the wrong plug to the iat sensor it will damage it by melting the sensor (you will usually see visable damage on the tip of the sensor).
3. Check the IAT sensor with an ohm meter per the helms manual specs.

Alternate solution is to tow the car to your tuner to have them plug in an ecu/laptop & datalog what is going on to see if the ECT/IAT/MAP/TPS Wideband sensors are reading as they should....

 

Check your datalog and see where your map signal is at idle. Did fuel pressure change? Any cels on?

 

No chance you've got an exhaust leak before the first O2 sensor, is there?
Jim

 

this

i shouldn't use such definitives, but the only thing that has enough enough 'power' to cause such a problem is the iat. unless of course your wideband is giving false readings or the ecu has **** the bed.

 

An exhaust leak located before the O2 would cause it to show lean.

OP,

When the AFR's peg rich how does your engine react? Does it stumble or stall or continue to run? If it continues to run and doesn't stumble I would check your WBO2 sensor. If it does stumble and/or stall. Check your datalogs for any abnormal sensor voltages/readings, IAT, TPS ECT...etc..etc..

 

This just happened to me with my H22, my problem appears to be a faulty O2 sensor or bad wiring to the O2 sensor.

I'm installing a wideband today, so I can run in closed loop again.

 

It sounds a lot like a faulty O2 and/or controller, especially if it's close to your turbo you probably overheated it. Typically when they burn up they'll only work at low throttle at first and then flip out.

 

I just posted this on another thread. I have had the same problem with ectune. I opened a new file and copied and pasted everything to the new file and problem went away. I have had other strange things happen as well and always opening a new file and pasting the tune into fixed the issue. This is annoying but I now make this a standard procedure after tuning. It seems as if the file gets buggy after modifying many times during the tuning process. My fear is that timing will go wack or fuel will go lean during a wot run.

 

this is oreozzz postin from a friends account.

Sorry guys, totally forgot about this thread but thanks for all the input and feedback. We pretty much have it narrowed down to the injector drivers in the ecu. The smart thing to do would have been to just swap another ecu and try it before anything but of course we didnt do that. First we took out the resistor box because we measured the precision 1000cc inj and they read 2-3 ohms but at the inj clips, it read 0.00 all across. Okay, resistor box might be shot, take it out and solder up some radioshack 10 watt 10 ohm inline resistors... same thing. Take both the resistor box and the inline resistors, measure them with the multimeter... resistor box 6-7 ohms, inline resistors 10 ohms on the button as well. WTF. Then i figured my car needed a new wire harness either way so i pick one up for a steal at $50 and now im gonna solder in the inline resistors back in with the obd1 inj clips, do the harness up all nice with shrinkwrap and some loomage. Put it back in and try it with a diff ecu. Its a bitch to test/replace the inj drivers at QM3 and QM4 so im just gonna try another P28. Unfortunately, i dont have anything to datalog with myself and the few i do know are super busy lately so i've been on my own besides my boy whos account im posting from right now.

 

The solder points at the drivers will probably look burned and/or smell like dead fish if they're bad. You can check directional continuity from pins 2 >| 3 and 7 >| 8 in either driver if you get bored.

 

Hey guys, im back. Unfortunately i dont have anything to datalog with. All i have is a multimeter as of right now. I changed the whole wire harness in the car and soldered in inline resistors. I checked at the inj clips for resistance when i first put the harness in and it read 10.00, boy was i excited just to find out that i start the car and it does the EXACT same thing. I measure the inj clips again, boom 0.00. How the hell could that happen? I even moved the grounds. I tried two diff ecus, same thing. I tried those diff ecus in diff cars and they work perfect. What am i missing here! All i did was take the swap out and put it back in, didnt even take the old harness out of the car! This problem is driving me crazy, no matter what the car pegs 10.0 on my wideband and there is no resistance at the injector clips. The old harness had an oem honda resistor box, took that out tried measuring with NO resistor box... still 0.00. Put a new working harness in with inlines, same thing. Can anybody offer any other input?

The IAT sensor plug is correct and i checked to see if it was melted, everything looked fine. Double checked over everything, looks fine. Changed plugs to some fresh ones, tested resistance at the injectors themselves (precision 1000s) and they all read 2-3 ohms. the inj clips are getting power to them... im at a loss.

The engine runs fine while its rich also, recently it started kinda stumbling at idle but once you give it gas it clears up and revs fine. Motor is fresh with 0 miles, tranny is rebuilt. I dont understand how this could happen from simply rebuilding the motor/tranny and putting it back in the car without touching ANYTHING else. Makes no sense. Thanks for your help though guys, its much oblidged(sp?). I might just have to end up towing it to my tuner so he can datalog and see if anything is off.

 

Anyone else have any ideas? Gonna end up just bringing it to my tuner and im sure he can figure it out.

 

I am having the EXACT same issue.. tried different chips, ecu's, and my innovate wideband is stuck at 10.0.. moves around a tad while driving but 10.0 at idle. smokes fuel. chokes and dies. checked all sensors, wideband wiring, resistor box wiring. all I did was basically take the swap and put it in another car. IDFK!!!! help us..

 

how is your map sensor setup?

 

My car is a 92 so my map is on the firewall. its hooked up fine and throws no codes.

 

i would do a easy check with brake clean

heres one of my proud stories. i once tuned a car that had the same problem. no matter how much fuel i took out, it would go rich on my wideband. had plug on engine map also had the tps plugged in correctly too so i spent time im thinking stuck open injector then i noticed a map sensor on the firewall that also had a plug on it but it also had an open vaccum port on the firewall map sensor. swapped map sensor plugs and tuned car, everything fine now. lol

 

Whats up guys, oreozzz here again. Same thing so far, tried 3 diff GM 3 bar map sensors, different temperature sensor. Main ground for the battery cause its in the trunk was a lil shitty so i cleaned it up, same thing. It does the exact same thing your sayin brandyn and i checked everything you did plus more. Diff maps, chips, ecus, harnesses... this is driving me nuts right now. I have my car at my boys shop right now and theyre gonna try to figure it out. He has another set of the same exact injectors (Precision 1000s) so were gonna switch em, he also has an s300 so were gonna throw a similar map on start the car and see what happens. hopefully they can figure it out, if not off to the tuner it is. Its drivin me insane. I really hope you can find out what it is or i do so we can help each other out, best of luck bro.

 

ya I took my resistor box off and threw on stock injectors and the car won't even start! I'm really baffled at this point. the car only runs w a resistor box. hopefully some datalogging will uncover your issues.. post as soon as you figure somethin out. thanks for letting me thread jack lol

 

welcome to tuning with crome

 

brandynEG, what ecu and program are you running?

 

socketed p28 with a phearable chip right now.. nothing to datalog

 

brandyn, what injectors was the map made for? so what injectors did u have in there? did u redo the map for the new injectors?

oreo, what injectors u got?

 

the map is for the dsm 440's. it should still at least start though right?