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'85 Cadillac Fleetwood FWD Hearse '94 Sedan DeVille
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Discussion Starter #1
Hi all,
I've got a '94 sedan deville with a 4.9 and 102,000 miles on it. When I drive to say, my girlfriend's house (aprox 20 mins of driving, a mix of country roads, interstate, and then suburban roads) on a HOT day..(like yesterday temp of 90-96) If the car sits for 10-20 mins, when I start it up again it runs like crap..rough idle, sputtering, the whole 9 yards. i rev it a couple of times and drive for say, 30 seconds, it runs great..so what gives? it has had new cap, rotor, wires, plugs (they are a heat range cooler than stock b/c of spark knock) egr valve and a/f. The timing is at stock setting, and i'm running premium fuel. Anybody have any ideas? They would be Much appreciated!!!
THANKS!:hmm:

Edit: this only occurs at a HOT start-up
 

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'85 Fleetwood FWD
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728 Posts
Not familiar with that engine injector system, but maybe you some leaky injectors, making for an overly rich mixture on hot start. On a cold start, the fuel would have evaporated during the cool-down. When you rev it a bit and start driving, it could be clearing the plugs etc from fuel fouling.

Just an idea for you to check out. Others here have experience with the fuel rail/injectors on that engine.
 

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69 Thunderbird | 90 Seville | 03 Corolla | 89 Marquis(scrapped) | 72 Torino(scrapped)
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2,026 Posts
I've heard a leaking FPR can cause that. Pull the hose off the nipple before your next hot start and check for signs of fuel.

Any trouble codes
 

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'85 Cadillac Fleetwood FWD Hearse '94 Sedan DeVille
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62 Posts
Discussion Starter #4
It isn't showing any codes at all, and i'm kinda leaning twards the leaky injectors b/c i've noticed some black smoke when it happens....and where is the FPR?
 

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76 Eldo (54k), 76 Eldo (52k), 78 Eldo (9k), 85 Deville (43k)
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668 Posts
definitely leaky injectors or leaking fpr--or both! 4.x PFI engines are known for eating injectors. that's why i sold each of my 4.x powered cars before 80k miles. i could tell they were starting to go bad.
 

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69 Thunderbird | 90 Seville | 03 Corolla | 89 Marquis(scrapped) | 72 Torino(scrapped)
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2,026 Posts
The injectors are a piece of cake to change - definitely not hard enough to justify getting rid of the car. Unfortunately the only sure way to see if they leak is to pull the fuel rail with the injectors attached and run the pump watching for drips. Of course if you've gone that far you might as well change them(and the FPR as well). I upgraded mine to the Bosch type III's for $150 and about 4 hours work.

The engine doesnt eat them. They are simply a bad cheap design that are know for shorting out. I got my first bad one at 67K. It read 1.2 ohms. The rest were 10 ohms and below - on their way out. They should read 12 -17 ohms.

I have pics of the fuel rail removal here: http://s106.photobucket.com/albums/m280/merc892003/?start=20 Theyre not exactly in order....

And a nifty how-to guide here for which I take no credit: http://www.cadillacforums.com/forums/cadillac-tech-tips/141351-4-5-4-9l-injector-replacement.html
 

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'85 Cadillac Fleetwood FWD Hearse '94 Sedan DeVille
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62 Posts
Discussion Starter #9
wow...thanks everybody.....so if it is the injectors, the Bosch III's are better than say, stock replacements?
 

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'85 Cadillac Fleetwood FWD Hearse '94 Sedan DeVille
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Discussion Starter #11
ok...so i found some injectors at rockauto.com that I can afford...is it best to just replace all 8 at one time? or just one or two, untill i find the offending injector(s)?
 

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69 Thunderbird | 90 Seville | 03 Corolla | 89 Marquis(scrapped) | 72 Torino(scrapped)
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If you replace just one, you will end up pulling the fuel rail up to 8 times as each injector dies. If one or two are bad it is very likely that the rest are very close. A shorted injector can damage your computer. Mine was VERY close at 1.2 ohms. Any lower than that and I would have had to buy a computer.
 
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