Ok guys took the car out watching some of the pids. Im thinking either the alternator isnt putting out enough or something is drawing too much power like maybe the fuel pumps. Watching the VPWR PID with the diablo im seeing it dip into the 12.8V range. Not sure what these cars are seeing under heavy loads?? That and when watching the MAF PID with voltage it gets funny when it starts to have dead spots, and also when it hesitates from the start. So can anyone on here tell me what kinda VPWR theyre car has under WOT?? Thanks ahead of time guys!!
Voltage??
- Thread starter justa03
- Start date
Depends on what you were running at the time. Headlights/foglights/stereo/fuel pumps/cooling fan etc. all on?
I have the Start N Charge 160 amp and my Car never goes below 13.6-13.8. Sounds like your voltage regulator may be going, or your brushes are worn.
13.7v@7K rpm,no lights,a/c or radio.
my car does this aswell.. i dont have any hesitation tho. at wot past 6500rpm she drops for a split seccond to 12.8 but the fuel pumps voltage stays the same? check your f/pump voltage. if thats droping ANY, then change that alt!
Nothing was on at the time besides the car running. Yea im gonna check that fuel pump voltage tonight probably. Finally get the car back together and running with a good tune and now this. Just makes a guy wanna throw a match at it!! UGH
1st off check the battery with eng off after the car has been sitting at least an hour it should be 12.6 v if the batt is less than that it is discharged or has a weak or dead cell and it wont fully charge but if the batt is fully charged then crank it and it should be 13.7-14.6 v if its any less check the voltage from the batt terminal to the batt cable on each cable and note the voltage drop, it should be no more the .3 v on positive and .1 on negative if its more you have a bad connection at the batt. Then if thats ok check batt terminal on negative to engine ground should be less than .1 v drop and then check positive terminal to alternator terminal should be less than .3 v drop if they are more than that you have bad cables or loose connections, If those are fine then probe the output terminal on the alternator and the case of the alternator. If it shows less than normal charging volts the alternator is going bad. Do that then let me know whats going on..
Tim
Tim
I think that's perfectly normal. When the fuel pumps are wide open they draw a good bit of amperage and when the fan is running that's another 40 amps or so, that plus other draws are easily capable of dropping the voltage below 13V under certain conditions. I wouldn't be concerned unless you see maybe low 12s or under. If the system ever reads below battery voltage when the car is running then this is an indicator that the alt is not keeping up with demand and that power is being discharged from the battery.
You really need to dowse it in gasoline first or else the match will just bounce off and go out.
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