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1990 Cadillac Eldorado

05-18-2006, 03:17 PM
Hi, My grandparents recently gave me a cadillac and it wont fire unless i run gass down the throttle body which is consistant with a bad fuel pump which i have not yet changed but i created a little contraption to make it run.... poke 2 holes in a oil bottle and fill it with gasoline and sit it on top of the throttle body and she runs...shitty...but runs but while she was running i got 4 codes
So i am curious WTF these codes are and if there is a site that will show me the equivelent to all them codes i have tried finding somthing alll day well thanks for any help hope to hear back soon.

05-18-2006, 03:40 PM

For the starting problem, in addition to the fuel pump, also consider...
Low on gas
Fuel pressure regulator
clogged fuel filter

05-18-2006, 04:43 PM
She has 5 gallons in her and this car ran fine untill it was parked for a year then it fired right back up and it got moved to a different spot and sat for about a year (over the winter and summer) then i went to fire it up and poof wont run rolls over fin but no start and no fuel pump hum so i was wondering how the heck does a fuel pump go bad just sitting there so is there anything else it could have been? Oh and does anybody know which wires are fro what in the trunk where it goes from in the trunk and down through to were that tank is so i can test the wires?
Thank you

05-18-2006, 05:43 PM
Five gallons of fresh gas or old gas?
Take the gas cap off and have someone turn the key to the ON position while you have your ear at the filler. You should hear the fuel pump start up then stop. If you don't hear anything, the fuel pump or the fuel pump relay may have failed.

05-18-2006, 08:06 PM
No buzz comming from the filler cap and where the heck is that relay? i have looked all over for it and do u know the list of cars that the pump is compatible with?

05-19-2006, 06:02 AM
Go here...
Select "parts catalog"
Look up your pump then cross-reference it.
Before replacing the pump you might want to put a pressure gauge on the fuel rail to verify there is no pressure.
I don't know where the relay is on your car.

05-19-2006, 11:58 AM
There is deffinately NO pressure at all while i had the car running i took a mini screwdriver and pressed the button in on the testing port and no hiss and no gas came out so i think its dead and i figured out all will be compatable with it ..basically anything GM between years 89-94

Thanks again

05-19-2006, 03:45 PM
If you have no pressure, either the pump is bad or the relay supplying power to the pump is bad.

05-20-2006, 04:44 PM
Hey i got it running it was a bad pump thanks guys BTW the pump out of older gm veichles all fit in it i put a pump out of my 1990 pontiac grand prix in it

05-20-2006, 04:46 PM
Hey i got it running it was a bad pump thanks guys BTW the pump out of older gm veichles all fit in it i put a pump out of my 1990 pontiac grand prix in it
How do you know that pump ,even though it fits, has sufficient volume and pressure for a signicantly larger engine?

05-21-2006, 10:00 PM
because i tested it and am getting between 39-44 psi full time at idle i get 44 and as it revs up it slightly lowers but runs fine except for a little miss but that mostlikely because the plugs have about 100K miles on em so thats my next issue to address and same for the wires and has the origonal cap/rotor/coil at 127K miles on it so i will probably end up putting all new in ever tho the coil probably wont be nessecary but will neway thanx and if anybody knows of any issues i should be watching out for in that car let me kno ;) thank u!

05-22-2006, 06:50 PM
Ok, so after all is said and done it has 100k plus on all the tune up items, and there is still no defintive info if the pump installed is the same for the Caddy, volume wise or application.

05-23-2006, 06:46 AM
if the grand prix has a 2.3D, or a 3.1T engine code, the fuel pumps are the same as the 90 eldorado.

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