So while chasing down my vibration, I am noticing a fuel smell often while car is off or running. Oil reeks of fuel and before I go changing parts, I did some tests.

All injectors show a resistance of 13.2 ohms then slowly drop to 12.5 if I leave the leads on for more than 10 seconds.

All injector plugs show 12+ volts with ignition on.

Fuel pressure is 34 psi when turning ignition to “ON”.

Fuel pressure is 42 with car running.

I unplugged each injector with motor running and all made a noise change except for 6.

I will be pulling the rails next to see spray patterns. Any other places to look?

 

Sounds like you have a leaky injector. It should be killing the plug on that cylinder. I'd be tempted to pull the plugs cold after it's sat all night to see if you can find the wet one. If it's leaking pretty bad I also wouldn't be surprised if you could use compressed air and actually blow fuel out of the cylinder..

 

Forgot the part where pressure did not drop more than 2 psi after an hour.

 

Yeah but If it's getting in the oil it's only coming from one place, an injector. Or when it does run it's running so pig rich that it's flooding the cylinders and still getting past the rings. In that case you should be seeing heaps of black smoke from the pipes.

 

Def no smoke. So if I am not losing PSI, how do I tell if the injector is leaky?

 

Do you have a miss on start up? That's one way, another is just as you've stated earlier, you can pull the injector rails, prime it and watch for the one that continues to drip. It's gonna get messy probably but you'll see it.

 

If your oil is saturated with gas, don't start it up until you figure out what's wrong. You keep running it your bearings and cylinders will wash out.

 

No miss on start up. Couldn’t get to pulling injectors today. And yes it is sitting for now.

 

Ordered new rings just because these are old and if I tore one, I wanted to have them. I get the two o-rings for each injector, but what is the metal “bushing” that comes in AC Delco 217-3102? I am missing 3 of these on the original injectors. They are pumpkin colored on the ones in there now

 

 

Replaced the injector that I thought had a miss and no change. Injectors are fine. I think it was just myself making up the miss. Runs like a top. However the oil was the color of Dr Pepper and was thinner than it should be. Going to keep track of when oil starts to smell like fuel again. Or set it the whole car on fire.

 

if you do have gas smell in oil and the oil appears to be thinner and not the right color you need to find out why. You will wash out cyl and kill bearings if that is the issue you are having

pull the rubber nipple of the FPR after you shut off motor. Is there any sign of fuel in it?

if so FPR is bad and leaking but the injectors would be the reason fuel is entering motor. A scan of your STFT would reveal if your tune is rich. Things like a exhaust leak pre 02 sensor will cause the PCM to read lean and dump fuel for example making your car run pig rich. leaking injectors would let fuel into motor that is not ignited by spark and cause fuel to be in oil

If you "smell" fuel you have a problem and if you have a fuel leak external of engine.....fire can be caused

 

The FPR is dry. I have to drive it some more to pin down the fuel smell. Engine is dry and it just smells rich not like raw fuel.

 

What do your spark plugs look like? Black and sooty? Or a nice tan brown?

Rick

 

 

big difference in "smell" of raw vs "rich"...so if you mean it smells rich from exhaust (generally you smell that from rear of car or if running a car in garage where exhaust stays in the garage) and your oil smells of gas and is discolored than "something" is causing the car to run rich

certainly pursue any "raw" fuel smells if that is also occurring but I suggest you get some data scans and look at 02 & STFT which likely would show rich then find the "why"...which as noted earlier can be pre 02 exhaust manifold leak...including a broken manifold bolt (not uncommon) among other possible causes....like a "leaking" (read not due to O ring but faulty injector itself that leaks). One way to find the later is to pull fuel rail and turn key on to see if one or more injectors are "dripping"..although this can be a mess so have rags, etc. laying on engine to absorb the gas.

 

More diagnosis is required for sure. I do know when my buddy scanned it weeks ago there was a quad driver and egr code. I am assuming the egr code is due to the aftermarket manifolds until I dig in further. I read the computer is sensitive to the pressure of exhaust gasses in the system and aftermarket headers cause this code. I was not there to see the codes on his scanner.

I think the raw fuel I ended up smelling was my gas can venting because it was hot in the garage and not the car itself. It definitely smells rich vs raw like when standing behind it. There is no smoke to speak of though upon start up or while running.

I still need to do a compression and leak down test which of course no one thought of when we did the plugs and wires.

 

Would a “start fresh” tune from someone like MadZ28 be a good spot to start?

 

Jon

what year is your car?

 

1995 lt1