Cadillac Repair: 93 Eldorado sputters, coughs and surges, vacuum leaks, financial restraints

Question
QUESTION: "93 Eldo coupe with a 4.9
my problem is intermittent.  sometimes it runs fine.  the other times it surges and sputters when throttle is applied.  another weird symptom is while driving the blinker can cause surges in time with the blinking lamp.  I checked for and repaired two vacuum leaks and used throttle body cleaner on the black residues in the TB.  Could it be a wiring issue?"

ANSWER: Very unlikely.

IS or HAS the CHECK ENGINE light ever illuminated on the dash while driving the vehicle ?.

---------- FOLLOW-UP ----------

QUESTION: yes, the check engine light does come on but not all the time. The fact that it doesn't consistently have this problem is really confusing me as to where to start troubleshooting.

I just started the car and pulled the codes.  The Check engine light is on and my codes came up as:
P030 HISTORY
P031 HISTORY
P053 HISTORY
P091 HISTORY
PO98 HISTORY

I039
I052

NO ACP
NO SIR

The car has 95000 miles, I've been slowly restoring it but I'm just a novice and due to financial restraints I have to fix this myself.  I did take 4 years of auto mech in high school which taught me how to turn a wrench but I'm not good at troubleshooting fuel injected vehicles. I can tell that when the engine acts up it is not burning the fuel completely.  Could this be as simple as a tune up even if the problem is intermittent?  I wish I had a scope.  All the forums I have read confuse me with unlikely wiring issues that cause the same problems.  
Thanks for your help by the way, i can sure use it.


ANSWER: FIRST, Clear (erase) ALL the codes from the computers via the climate control panel ONLY, Drive the car and see which codes return and which are HISTORY and which are CURRENT.

Have you tried adding a can of dry gas to the gas tank every once in a while to break up any water particles that may have accumulated ?.

---------- FOLLOW-UP ----------

QUESTION: how do I clear the codes?  I ran it out of gas a couple days ago so it's pretty fresh,

Answer
Try 2 cans of dry gas anyway.


If you are mechanicaly inclined or know of someone who is, You will need a DIGITAL VOLT/OHM METER, Simple electrical schematics, Test procedures and picture locations of the components within the system that is causing you problems of which can't be done on this website which only allows one picture. I do not have a website so you will have to e-mail: onlineautohelp@msn.com in order to obtain the information.