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Eldorado
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Discussion Starter #1
So my 1990 Eldorado Caddy has been acting up the past few months getting worse and worse. It runs rough at idle (like a old farmers tractor) but when I put it in drive or reverse it will start to get worse hot or cold more of a shaking then anything. It will also bog down when I push it on a stop or light. NO CODES at all which makes my head hurt...........

Ive changed the spark plugs and wires bought a new distributor cap and checked to see if the exhaust system wasn't bogging it down. EGR valve looked good last I checked and no known vacuum leaks.

Anyone got any ideas just throw them at me because its getting frustrating.

Pretty new to fixing cars since really the caddy has been a powerhorse since I got it about 9 years ago.

Thanks
 

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White Diamond '03 DHS (with DTS floor shift)
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What engine, 4.9? Are the EGR tubes down in the TB open? What's your fuel pressure?
 

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Eldorado
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Discussion Starter #3
What engine, 4.9? Are the EGR tubes down in the TB open? What's your fuel pressure?
4.5 L

Not sure what the TB is if you could care to explain for a newbie..

Pressure was sitting around 31 psi think Ill pickup a new fuel filter

Thanks
 

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White Diamond '03 DHS (with DTS floor shift)
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TB = Throttle Body. I think the 4.5 has the EGR tubes down there as well. Is it TB injected or multiport?
 

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Eldorado
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Discussion Starter #5
TB = Throttle Body. I think the 4.5 has the EGR tubes down there as well. Is it TB injected or multiport?
Hit me as I was busy cleaning it :thepan:

I didn't look at the tubes at all since I kinda rushed the EGR.. Guess Ill have another go at it.

Not sure which it is 2 valves is all I can tell you if you can identify them like that ( totally new to cars :( )

Something new though when I turn on the A/C today I got a extremely strong fuel smell and the exhaust smelled horrible like sting your eyes bad.. Almost like the engine wasn't burning off all the fuel or something...

The exhaust problem has been around for a long time now but the A/C smell seems new.. Any insight

Thanks for your time Ranger
 

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White Diamond '03 DHS (with DTS floor shift)
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Not sure which it is 2 valves is all I can tell you if you can identify them like that
That sounds like TB injected. 2 injectors in the TB.

Not sure which it is 2 valves is all I can tell you if you can identify them like that
That sounds like a fuel leak.

and the exhaust smelled horrible like sting your eyes bad.. Almost like the engine wasn't burning off all the fuel or something...
That sounds like an extremely rich condition.
 

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Eldorado
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Discussion Starter #7
That sounds like TB injected. 2 injectors in the TB.


That sounds like a fuel leak.


That sounds like an extremely rich condition.
Gotcha

Where would I look since I havent see any fuel while working with the car just oil

OS2 Sensors where running avg .52R and .49L at idle if that makes any more sense to you then me.
 

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White Diamond '03 DHS (with DTS floor shift)
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If you smell raw fuel through the vents then look at the fuel lines under the hood. If you smell it from the exhaust then look at the injectors maybe. They should pulse as opposed to spray continuously.
 

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1991 Cadillac Seville - 1998 Cadillac DeVille - 2013 Cadillac XTS4
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If you have a 1990, it probably has the 4.5L MultiPort Fuel Injection. I have a 90' Seville and a 91' Seville and both have the MPFI engines. I just had the same problem with my 91 which has the 4.9L. I put a rebuilt set of injectors in it and WOW, what a difference! Runs like a swiss watch. I only had a suspicion that it was injectors because whoever had the car before me changed only 3 of the injectors. The rest were the original gray Rochester injectors, which a few were leaking. I put in a rebuilt set of Bosch, which fit just fine and that really did the trick. It's a little time consuming, but not a terrible job. You have to remove the fuel rails on each side along with the cross-over tube which holds the fuel pressure regulator. Best to change that too. It's not too expensive and being that it is mounted from the bottom side of the crossover tube, that is the time to change it. Make sure you change all "O" rings as well. Not sure if that is what ails yours, but mine was running horrible. Roung idle, missing, backfiring, etc. Like I said, it now runs perfect. You can find them from a few different sources on eBay. I paid $129 for the entire set of 8. Just make sure you get a set of "Flow Matched". Hope that helps.
 

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1999 Cadillac DeVille
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279 Posts
My money is on the injectors.

$117.79 ea. for delcos on RockAuto or $71.79 for delphies.
 

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Eldorado
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Discussion Starter #11
Well I let the A/C run today for 30 mins which cleared up the fuel smell inside at least...

Injectors seems to be the most likely culprit going to see if I can get them cleaned locally before I put out the cash :). Hopefully it wont cost me a lot haha. They have never been touched in 20 years apparently when I called the original owner who forgot to give me the work orders, lucky he still had them.

Also the muffler died on me 2 days ago.. like riding around with tin cars attached to the bumper.. good times..

Thanks again everyone.
 
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