Cadillac Repair: my car is an cadillac seville..., throttle position sensor, fuel pressure regulator

Question
my car is an cadillac seville 1993 4.9
i'm trying to replace the throttle position sensor and i'm having problem's setting it to it's proper position
the car won't stay at idle .it keep's cutting off and it's idle is very low.and fuel economy keep's changing and every once in while it blow's black smoke and i smell gas very strong.

   i,m also having problems with my speedometer it cut's in and out at will and my car does not accelerate right when it's not working and it just spins and move's when i'm sitting still in park

              thank's for your answer's to my previous question

Answer
Hi Lionel, To replace the TPS and perform all the basic adjustments would require some special tools and meter or be able to use the on-board diagnostics that is built into the climate control panel. Alot of techs don't know how to set them up properly eithor and you really do need a shop manual to follow the procedure. In a nutshell you warm the engine til the thermostat opens, ground the set timing connector and set to 10BTDC, remove the ground and ground the generator connector, retract the ISC motor and set to 550rpm, TPS to .50v, then turn the engine off but key on and then extend the ISC motor until the TPS reads 1.15volts. Then retract the ISC motor and shut off the key. Disconnect the battery. Reconnect the battery and then relearn the TPS and idle settings in the computor. At that point the engine should be purring right along. However if you need tune-up stuff, a fuel injector or two or there is a hole in the fuel pressure regulator diaphram then you will need to correct those things before doing all the adjustments or the engine won't run right. I had a Caddy in the shop recently that the owner thought all he needed was plugs and wires but what he didn't realize was 6 or his injectors were also shorting out and without replaceing them the engine wouldn't run right.
The speedometer could have a problem with it or the speed sensor in the trans, a wiring problem somewhere, a stray spark jumping from a faulty sparkplug wire to the vehicle speed sensor wire or a bad ground connection on the negative battery cable near the starter.
Both of your concerns will require a sharp tech to correct so chose your shop wisely. If the engine is running ruogh you could do the tune-up stuff yourself and take it to the shop for the rest. Hope I was of some help and glad to know I helped with a previous question. Bill