Harunted 99 LS

[nonZero]

I have taken my 99 LS to an electrical shop 2 times and they have basically told me that my car is haunted (they have no diea whats wrong). The second time i took it to the shop they cleaned my ground connections and checked some wires, which fixed my problem for 2 months, but it has come back again since then. I have checked the forums before I posted this and havent really seen anyone else with this problem.

Basically my situation can go down one of two ways:

1. I come in to start my MC, (either first time of the day, or after i have already been driving doesnt matter) when I turn they key to run, before i even go to start, the tachometer freaks out and jumps between 3000 and the redline. The needle moves back and forth faster than I could make it even if the engine is running and i stomped the gas pedal as erradically as possible. Then when I goto start the car it cranks but doesnt start. I have to turn the key back to "off" then I can start it up fine. Sometimes I have to try and start it a few times while the tach goes crazy until it finally starts like normal.

2. I am driving down the road ( i used to think that it stalled more when it was wet outside but that hasn't been true lately) The RPM's just drop out like someone had a killswitch on my engine, then the engine is off while im coasting- and the tachometer is going crazy again, bouncing in the higher RPM ranges. I have noticed that my car is easier to restart in this situation than in the above.

This had happened in rain, after rain, in the summer, and now winter cold conditions. My radio has been on and off, and my heater/ac unit, or headlights don't seem to have an effect on it either.

The real kicker is that this problem is not predictable- as in I can't go outside right now and expect the tach to go crazy and my car to not start. I cannot get this problem to happen whenever I want to show the mechanics, but it has been happening more and more recently. On my way back home tonight it stalled on me 5 times during a 25 minute drive. I guess when it rains it pours...

--maybe more common after an oil change?
--no check engine soon light
--after it stalls i only see the oil and volts lights on (recently)

-any help or fixes for common experiences would be GREATLY appreciated!!
-thanks guys

[montecarlossfan]

well u might not waant to hear it but the best way to go is find a car optioned liek yours and redo all the wiring, the interior and exterior harnesses should unplug from each other making it not a terribly hard job, just a long one

[nonZero]

man thats hardcore, i took it to the dealer today, and got it back.
9 codes being sent
P0108 amongst others
new pcv valve?
total replacement and reprogramming of the computer

all covered under some 8 year warranty, lucky me.

trouble is that it stalled out on the way home two more times. lol! - i dropped it off again earlier tonight....

[HellzX]

I think the computer is confused and needs to be replaced.

[nonZero]

Originally Posted by HellzX

I think the computer is confused and needs to be replaced.

how right you are.
monday
1st time in the shop they said the computer was sending 9 codes, replacing it fixed that. told me it was fixafter they put 5 miles on it with no problem.

50 minutes later i dropped it off again and told them it was not fixed

tuesday
they said it was sending 2 more codes and they replaced either a PCM or ECM piece of plastic with computer boards on it which cost 450bucks told me they drove it 12 miles with no problems.

wednesdayuntil the tuesday after christmas
dealer drove about 20 miles "without problems" performed no labor, gave no bill.

my car still stalls, without the tachometer problem. and im betting that because the dealer had no service engine soon codes to work form they had no idea about how to fix it.

--maybe my battle plan should be to take it up there, have them tell me that nothing is wrong then offer to trade it in. 99MC only 28000 miles, hopefully be able to get something that isnt haunted.

--that problem with the tachometer freaking out while the car was not running was due to my drivetrain computer malfunctioning and still firing the fuel injectors eventhough the car was off.