smell of gas out of tailpipe

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  #1  
Old 08-13-04, 01:29 PM
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smell of gas out of tailpipe

1994 olds. bravada 3.4 vortec engine 115,000 miles. just did a tune up on it plugs,wires dist cap,rotor and fuel filter. seems to take a couple of seconds to start after hitting key. took it to garage and they checked the fuel pressure and said it was 60 at start up and 54 at ideling. said it wasnt hold the pressure in the line . turn on key wait about 4-5 seconds to start car to let it build up pressure in the line,but on bringing on home it runs like crap. idles very ruff and shakes like the dickens. smell of gas out of tail pipe . have drivin it about 100 miles and used a half tank of gas, called them today and said bring it back on mon. they said no idea why . any suggestions before returning vechicle?
 
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  #2  
Old 08-13-04, 01:49 PM
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I would guess that the fuel pressure regulator is leaking and it's inside the intake plenum as are the injectors.
 
  #3  
Old 08-13-04, 02:00 PM
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thanks, would this cause the fuel to burn up like it is?.the tail pipe is covered in black soot on the inside, does this require to drop the tank or where is it located?intake plentum where is that at?
 
  #4  
Old 08-13-04, 03:45 PM
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the intake is on the top part of the engine the cover that says vortec on it screws into the upper intake, the upper intake must be removed to change regulator injector assembly and it is usually a good idea to change the fuel inlet and return lines that run under the intake also.
when you shut the key off fuel pressure should remain constant for a good length of time if it drops you either have a leak or a bad check valve in the pump.
when a leak develops under the intake it usually causes the vehicle to be slow to start as it is flooded with gas and if bad enough will usually gas foul out 3 spark plugs causing the engine to run rough as it is only running on 3 cylinders at lower rpm.
 
  #5  
Old 08-13-04, 04:22 PM
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thanks . is this a diy job or a garage job. like i posted before they said it wasnt holding pressure so this would lead to the regulator? if i take it back what would i be lookin at cost?.
 
  #6  
Old 08-13-04, 04:58 PM
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I would probably return it to the shop to make sure that is the problem and then get some estimates on fixing it, this is not that uncommon of a problem and most shops should be familiar with the problem and should be able to determine if there is a fuel leak under the intake fairly quickly.
if you are not real familiar with vehicles I would probably suggest taking it to a shop, cost wise can vary greatly depending on labor rates and parts markup but to replace injector assembly, fuel line nut kit, upper intake gasket, and labor you would likely be looking at 500-800 dollars.
and the vehicle may be in need of more work to get it running properly such as sparkplugs can get gas fouled and may need changed again. gas can contaminate the oil and may also need to have the oil changed.
 
  #7  
Old 08-14-04, 02:14 PM
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thanks for the info, just wondering could a bad injector cause this?.on this car is the fuel pressure one whole piece or can they just replace the regulator?so with it not holding pressure with engine off this would be the regulator?. im takin it back on mon. will let you know what they say.
 
  #8  
Old 08-15-04, 04:34 AM
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The "W" engine in the bravade(eigth digit of the vin) this could be a leaking regulator, injector, or the fuel lines inside the plenum to the injector are cracked.
Not a DIY job. The regulator comes free with the injector assembly. They're pricey......around 400 bucks I think . Upon taking the plenum off to access the injectors, the plastic fuel lines to the injector should be either inspected or replaced as an insurance against it failing in the future.
 
  #9  
Old 08-15-04, 10:20 AM
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The injector assembly is available aftermarket and is possible for you to do if you take your time and make notes upon disassembly.$307 for the assembly,$35 for the regulator alone.You will need plenum gaskets also but I didn't price them but they are cheap.If you pull the plugs you will most likely see the passenger side black and the drivers side clean and that would indicate a fuel injection pressure regulator leaking.Upon disassembly you will see why.
 
  #10  
Old 08-16-04, 02:38 PM
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o.k. i talked to the mech. today and he said the 1 and 3 plugs where fouling out after restarting it.5 was ok drivers side ok, fuel pressure was ok. at this time wasnt for sure the reason for this ,when i mentioned the fuel reg. he told me that all plugs would be fouled, hasnt removed the plentium yet as it was the end of the day , he will call me tomorrow on more findings,he mentioned maybe the injector were stuck opened. thanks for the replies!!!
 
  #11  
Old 08-16-04, 05:30 PM
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I don't know the shop working on your vehicle but from the sound of things it may be the wrong one.Good luck.
 
  #12  
Old 08-16-04, 06:03 PM
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I think Davo may be right. Most of us use a scanner to diagnose those things leaking. He needs to get a look at the adaptives but it doesn't sound like he has a clue.
 
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