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Cadillac Repair/1993 cadillac eldo 4.9l won't start


QUESTION: Problem started after a 3" rubber fuel hose that connects the carburetor/fuel injection to a small vacumn like part that the fuel flows through.   I replaced the fuel hose that was leaking fuel and tried to start the car but the car want start.  I thought the battery was the problem so I replaced the battery since it was almost 4yrs old, but the engine will not turn over and start up.  I can hear the fuel pump motor in the tank and gas flows through the little hose that I replaced.  I took the battery back and they said that it was ok but recharged it anyway since it shown 90%.  Brought it back and reinstalled it and still no turnover of engine.  Just a thump sound each time I turn the ignition to on.  What seems to be my problem and is it something that I can fix myself?  Afraid to have the shop come pick it up as they will fix everything but what is needed.  Help!


The most common issue in these is the vats (resistor pellet in the key). Don't go changing anything yet.
Try tilting the steering column in different positions and see if the engine cranks. If it does get back to me. If it doesn't get back to me.


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QUESTION: Thanks Rob, I tried moving the steering wheel into different positions as well as using different ignition keys, but nothing happened.  The car's dashboard lights up showing alls OK but not cranking sound from the ignition, starter nor battery.  But the battery show 12.4amps in the information column.  Still get the thump sound when I turn the ignition to on.  What do you suggest?


Not sure what you are referring to as a thump sound. When not starting you may ear a relay make noise from under the dash.
This car is equipped bit the VATS which is not only an antique for security but was very problematic. two very thin wires (Similar to land line phone wires) run up and down the steering column going to and fro the ignition lock. They break inside the insulation and the resistor cannot be read by the computer from the key.
That is why I had you moving the column with the hope of attaching a broken wire. It works sometimes and sometimes it doesn't.
You need to get off the battery kick. At 12.4 volts, that is not the problem.
This is a cranking issue leaving you with two common issues if all the lights come on in the dash when ignition is turned to ON. Either a bad starter of you are a victim of this professionally engineered anti theft system that never stopped thefts and only the owner from driving their vehicle.

Dealer techs are very good at changing parts on a guess and first they would sell you a new $50 key. When that didn't work they would sell you an ignition lock with the VATS and install it to the tune of $750.00. Worse yet, if the starter is faulty, that would cost you another $300.00. I know this because I have seen it as a very common complaint from questioners.

Since I have dealt wit thousands of VATS issues, odds are that is what you are dealing with and no matter what, it needs to be bypassed. I do not know your mechanical inclination level. It is not real challenging to do, but yo need a ohm meter to read the resistance value of the key. Then it is a matter of getting under the driver's dash and going to the bulkhead and finding two white thin wires commonly in an orange sheath and cutting each about 6" from the bulk head and installing the correct resistor between the two cut wires. This essentially tells the computer the correct key is being used every time, lying to it. Dealers will not bypass this junk. Only after market alarm stores will. Chances are, the engine will start for you and you will never have this issue popping up again. VATS is notorious for standing owners!

Now, if it still does not start, place a test light at the starter solenoid. If the light lights up while someone turns the ignition to start, the starter is junk.

Starters do not normally fail just like that. You usually have problems cranking when warm first.

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QUESTION: Ok, I am with you on this.  I will get under the dash tomorrow and look for those two thin white wires.  I will need a  resister for each wire or 2 resisters to attach.  What would be considered the correct resister?  Also, what should the resistance value of the key read?  I will try all of this first. and Thanks for your help.


Using an ohm meter read the ohms on the black pellet of the key by placing a lead on each side of the chip.

Once you have the reading, go to radio shack and get the resistor of the same value. You are allowed 10% deviation.
Connection is very important and trying butt connectors does not always work. If you want to do it right without problems I would recommend solder and shrink wrap tubing. You can try red butt connectors, but the VATS wires are very thin and if you do, use electrical tape on the end of the butt connector and wrap to hold the VATS wires to the thi resistor wire.
You are only using one resistor. Used to be one of 15 but since 1992 went to one of fourteen.

You need to drop the black plastic hush panel and remove it fro the lower driver's dash. Should be a 9/32 or 7 mm (They are the same size) to remove the dash attachment. At the fire wall you will have two bolts or studs. If studs, remove the wing nuts. If bolts they are 10 mm.
The bulkhead is to the left of the column. Follow the steering column wiring to the firewall, you will find it.
DO NOT cut any orange wiring. The VATS wires are two very thin wires running into the same terminal in the bulkhead and the orange sheath is like a tube that goes over them. At the bulkhead you will see these two thin white wires. Give yourself about 6" from bulkhead and snip. Strip each side of the white wires and connect your resistor between.

See, you have nothing to lose here. You are not doing something for nothing. This crap will strand you in the future--Guaranteed! I have walked through hundreds on this site and ave done thousands myself!

That is the only way you can diagnose a starter as well. I would be willing to bet this will do it for you. As I said connection is everything and you will see the challenge, but you can do it.

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Rob Painter


Alarm system questions cannot be answered on this forum. These systems are not what I can answer. Without being physically at the vehicle and not knowing what kind of electrical service has been done on the vehicle, there is no possible way to give an accurate answer over the internet. My expertise is in Ignition/key based anti-theft systems. These issues include GM VATS (resistor chip in key blade) PASSLOCK (MRD)-ignition lock rotation based, no special ignition key and the PKIII Transponder (computer chip in key) systems. These systems are not alarm based and are integral with the starting of the engine. This is why I cannot diagnose alarm problems without physically looking at the vehicle: Alarm systems are a completely different annimal than ignition key/lock based anti-theft system. Many alarm questions come from vehicles 10 years old, and since older, many hands that had been involved over the years.I am an expert in all GM factory (ignition/key based)systems. Alarm system questions pose to many situations beyond my knowledge as to what has been done to the vehicle over the years. Some guy may have actually wired the stereo into the alarm system. Who knows? Over my past 30 years in vehicle wiring repair, I have seen unbelievable wiring disaters done by guys that consider themselves "mechanics." I have seen stereos and alarms intalled using surgical tape. I have seen modules burn up, un-fused circuits, wiring jambed between the doors and even lamp cord used for a starter kill. To answer alarm questions over the internet without examining the vehicle is like asking; What does it take to remove a dent?


Education/Credentials-ASE certified. 11 years with a GM dealer and 17 years with a repair facility dealing with only the repair of theft recovered vehicles.

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