: 99 STS Starting hard, STALLING..Help!!

04-25-05, 11:38 AM
Hello everybody, especially you Bobb (your knowledge is impressive :thumbsup:) this is my first time, so hope it works. (NOTE: If you recognize this it's because I brought it over from the Northstar Technical Discussion Area... thought it might get better mileage here!)

My buddy and I each own black 99 STS's and I have never been happier with a car, however my buddy's car is giving him fits :banghead: .

The problem: the car starts hard 5-6 secs of cranking, runs for a second or 2 then stalls.
All the lights in the dash die as this happens. You can immediately retry, and if you ar living right it will run fine, It most instances it will continue this behavior 10 to 20 times Well this is OK in a garage or your driveway but at an intersection, it is VERY embarassing, not to mention dangerous.

Things which have been done (not all pertaining to this problem).

O2 sensor replaced
ECM replaced
New plugs
New wires
New Crank Sensors
255/45R18 Tires on Chrome rims
Cross drilled rotors with ceramic brake pads
K & N Filter Mod (removed the wafer from the MAF Sensor)
Have completely disconnected the Instrument Cluster
Have completely disconnected the Security Module ( under the passenger side dash - glove compartment)
He has traded all the fuel modules/relays with my STS
He has traded the base under the coil pack with my STS

Still does the same ^**(% thing, very discouraging.....

To me it seems like a chip in the key/security problem!
I do no that he has not driven it for 6 months, you can do this when you have several vehicles, BUT Man summer is coming and this baby needs to fly!!!

I am not sure if anyone is familiar with this problem, but have to say that we are stumped.

Could use your help


P.S. The last crank sensor was changed last week and the car worked fine in the garage and on the way to work on Thursday am alas the trip home was back to the way it was???

Have ordered a new ignition insert to see if this is it, sometimes when you jiggle the key in accessory the dash will sometimes go out....hope this it!!

Has anyone had this problem??

I believe the next step will be a funeral!!!!

04-25-05, 12:33 PM
I will post the obligatory "are you getting any codes?" question. If so post them as they could be a huge clue (post the history codes as well, these will not cause a ckeck engine light).

It may be the ingnition cylinder or ignition switch, I have seen several other members on the board have problems with these - search the archives on it.

Do the dome lights , head lights or other power accesories die as this happens? If they do, I would check the charging system. Make sure the battery cables are tight and clean up any corrosion. Inspect the cables for any wear/burns/exposed wire. Check the grounding point connections to the engine and coil pack to see that they are tight.

Other things to try:

Give the fuel pressure regulator a quick check, remove the vacuum line and look for leakage.
Clean the EGR valve, a stuck open valve may cause driveability problems at idle

good luck

04-25-05, 01:43 PM
Let's see checked the Fuel pressure regulator it was OK. My buddy has the OBD service program on his laptop and NO codes.

Not sure about the dome lights, will check tonight.

Will pass the info along and see what he has to say.

Thanks for your input, appreciated.

04-29-05, 09:45 PM
WELL GUESS WHAT, Replaced the ignition plug in and it did the trick.
My buddy is all teeth.

Thanks for your assistance