ok im having an electrical problem. when my headlights are on, the car bucks. not a slight hesitation that people say get a pfc or a hks twinpower and it will cure but a bucking like damn, i cant drive stick type of bucking..lol

the car will buck when driving, like when im trying to drive in whatever gear..mostly in 2nd and 3rd..i cant even bring it past 3k cause it will buck and jerk from 2000-3000 up and down like a fucked up TPS..except im in gear..yes its confusing..

i tried adding grounds..i did 2 so far..from my alt bracket to frame and another from UIM to frame..all it did was smooth out my revs when going WOT lol..the problem was still there when i turned my headlights on..

so now i have 3 assumptions..

my air/fuel gauge wiring..yes it seems stupid but this gauge is the only thing fucked up in my car..im pretty sure the wiring is messed up which is shorting out somewhere or something..the gauge hardly ever reads and when applying extra loads (running the fans manually or stepping on the brake), the gauge will dim or show a different reading..its basically useless..

or it could be my battery??? the battery is about 2-3 years old..holds a good charge but maybe not suitable to run all those electricals?? maybe i need a stronger battery?? like an optima or something??

or could it be a problem or maybe another grounding problem within itself because my battery was relocated in my rear bin?? i havent added another ground to the battery.. should i?

its funny cause when my battery was relocated, i never had this problem with my headlights..from spring to the end of summer, i never used my headlights believe it or not LOL..i mostly used the car in the daytime. now that its getting darker earlier, i have to and thats when i noticed the problem..

i tried searching but they have given me answers that i knew already but not for my kind of problem. i really want to solve this myself instead of taking it to a shop..

any help would be greatly appreciated..

thanks

 

bump

anyone?

 

I would just go ahead and disconnect that gauge. I've seen many electrical problems brought on by poor or incorrect installation of aftermarket electronics. Troubleshoot with what you know first.

I'd also reset the ECU - undo the negative battery terminal, then hold down the brake pedal for 20 seconds.

Have you checked to see if the ECU has stored any codes?

Dale

 

thanks for the reply

umm this could be a noob question but can i just take off the gauge but leave the wiring there? like i wont untap the wire to the ecu or to the o2 sensor..ill just take the gauge off from inside the car and leave the wires open/there..will that work?

and yes the first thing i did was reset the ECU, i usually do that whenever the car runs funny lol and it basically works but this time it didnt. no i havent checked for any codes, the engine check light doesnt come on but ill check for codes still..

do you think the battery could be the cause? i have an in-dash dvd player, 3 gauges mounted on the a-pillar..maybe that extra electrical draw when the headlights are on is too much for the pos battery i have..should i just get something stronger just for kicks? i hear the yellow top optima is good for people who run alot of electricals..

this sucks because im pretty good in fixing cars, diagnosing is what i suck at and electricals are freaking tricky..

 

No, that wouldn't make a difference.


Check the hose from the back of the uim to the MAP sensor on the firewall. That's a common culprit for the symptoms you described.

 

nah that hose is fine

the thing is that with my headlights off/dash lights off, my car runs flawlessly, like no problems whatsoever..thats why i dont have problems with this car in the daytime..

its when i turn them on, i guess that extra draw for volts messes something up and i basically feel like im getting ignition breakup in the lower rpm's, like its not even driveable, it will buck and jerk like its hitting fuel cut and its about to stall..

so basically uninstalling the a/f gauge wont do squat?? how about adding another ground to the battery?

i think im gonna just get an optima, add another ground to the battery and pray to god lol

 

check the alt output at idle with the lights, ac radio etc on first. i guess it is possible the lighting for the af gague is going into the af meter signal wire which is also going to the ecu, so it sees an insane o2 reading.. but like dale said uninstalling the gague completly would be a good thing to do if the battery and alt check out.

 

will check the batt and alt tomorrow..

but about the gauge thing. could i just pull the gauge itself and leave the other wiring there? like the wiring that comes with the gauge, ill just rip that off the pillar, will that help? or do i have to completely uninstall everything?

 

to be sure disconnect it completely. especially where it feeds into the ecu's o2 sensor wire

 

well im not 100% if this is supposed to be installed this way but there is only 1 wire tapped into the o2 sensor wire..

like 4 inches of wire that comes out of the sensor itself, a light pink wire was tapped and ran across my firewall into the cockpit (i guess thats for the gauge)..

so i guess my question is, can i cut that pink wire and just solder it shut and take off the gauge?? i mean i dont think i can take off the tap clamp because its bit into the harness wire itself and i dont want to have to replace the entire sensor..ill leave the actual tap there but cut the wire on the other side and solder it closed so theres no open wire..should i do that?

 

yeah just cut the wire, and wrap it up with the harness with electrical tape You don't really need to solder anything, just cut it as short as possible from the o2 sensor wire, and wrap it with tape well with tape.

 

I would definetly check your alt.

 

ok i did the brief way of checking

car on at idle 14.51

car on with the fans (turned them on manually) 14.43

car on with the fans plus the headlights (the problem i was having) 14.32

does this seem normal??

mind you, i got these readings AFTER i uninstalled my a/f gauge..my gauge is no longer being powered, i cut the 3 wires off the gauge, then black taped the open wires closed so they wont touch each other..

i havent drove the car yet to see if the problem went away because my car is blocked by other cars so i will check soon..but do those numbers seem normal so far? i mean the 14.51 is normal i know, shows that the alt is charging the battery but what about the other numbers?? they look ok to me..

 

Your alternator seems to be working very well. My normal charging readinge are in the high 13's to low 14's at different load levels. I do see high 12' to low 13's at low idle (750 to 800) but find that expected with the alt under drive pulley at that rpm. I would double check the ground from the chasis to the battery (bare metal where ground is attached to the chasis) and a good ground (say from the started /motor to the chasis) I know my car has this stumble when trying to drive sensible (light throttle throught 3k) especially when cold. Good luck and let us know if you find the root cause that works. Jack

 

yeah i already singled out the alternator and grounds..

i highly believe it was the a/f gauge and maybe the pos battery i have..ill know soon enough when i go drive the car now that i dont have the a/f gauge..if the problem is still there, ill get an optima battery..if that still doesnt work..i guess ill take my car to a damn shop LOL

ill update the thread if anything..