challenging issue.... bad throttle response

[Insidious Surmiser]

I'm just going to give you guys all the info I have. I'm lost. I've been trying to find the problem for well over a month now. I, by no means, have given up. There's still plenty of work to be done, but a little insight will go a long ways. hope you guys can help

-dallas


problem source - o2 sensor heater wire grounded out on exhaust. After that, the car has had this problem.

codes - 41,42

symptoms - bad throttle response, stumbles from gear to gear or off idle. When idleing down the car wants to die. AFR at idle is normal when car is started(and ecu will flash no codes), but once the throttle is touched, it will stumble, then lean out to 16-18:1 when warmed up. AFR while driving is in the range of 9.5-12:1. (using innovative lm-1)

side notes - o2 sensor was replaced, and AFM is verified to be working correctly. TPS is also verified to be in good working order(according to tsrm), and is installed correnctly. Code 42 says "short or open in tps wire VTA(white with red stripe)". This wire runs from the tps to the ecu, and that's it. I already bypassed the wire to the ecu, and checked the wires at the connectors (tps and ecu). There is no short or open. :nono: :1zhelp:

 

[Insidious Surmiser]

guess i'm SOL eh? still need to do voltage spike tests on the ecu pins, other than that i can't really think of anything else...

 

[jetjock]

One of us is confused. Code 42 is for the speed sensor. Code 41 is for the VTA portion of the TPS. Both are easy to resolve. 42 will not effect mixture to an extent that it'll effect performance. With the TPS stop messing with ohms and start measuring voltage on VTA at the ECU. The ECU doesn't know ohms from shinola although you can certainly use an ohmmeter for checking the speed sensor. Lastly, your A/F problems are unrelated to either of these codes.

 

[Insidious Surmiser]

damn , well i knew the ecu was getting a bad signal already, but i can't figure out why. as for the afr, i don't know what's up. think i'm'll go over all my grounds and fusible links ?