Help diagnosing bad FPR/injectors

[lothos]

Hello everyone. This board has been an invaluable resource for me since I've had the 1995 STS, purchase Oct 31 2007 with 152k miles. Currently has almost 158k. I apologize in advance if this post is a little long, trying to get as much info out there as possible, and I have lots of questions I also apologize if I sound like a total newbie, don't have much experience with mechanics. ( I do learn fast though, and just tackled a brake line job outside in <30 degree weather with hand tools and jacks/stands. Not a fun three days. )

The problem is, on cold mornings I've occasionaly had white smoke that smells heavily of fuel out the tailpipes. I've been reading up on this, and saw a post describing a fuel smell in the motor oil and think I might have that as well. (took the oil filler cap off and sniffed. Might smell like fuel. The oil on the dipstick is dark and not runny/thin) When it's been extremely cold out the car has idled rough on cold morning starts with the white smoke. The white smoke smells like fuel and is really harsh to the senses. There was an egg/sulfur smell one time when the idle was really rough one morning.

I had the coolant flushed in the first couple days I owned the car. I had a metal coolant line by the firewall burst not long after that and all those hoses and pipes were replaced along with new coolant. The mechanic replaced the rear valve gasket during this repair, stating that he had to take it off to reach the hoses. There don't seem to be any coolant leaks currently, although I'm watching the front radiator hose, having seen some drips from the clamp area by the battery. Coolant has stayed at a constant level, roughly 2 or 3 inches below the top of the bottle. The car has never overheated on me, the highest temp I've seen is maybe 220, and that was right after the hoses were fixed and I assume the car was burping air bubbles. Temp normally stays in the 195-205 range.

My oil life monitor is at 48%. I'm guessing it's been around two thousand miles since the oil change, probably more like three thousand. I just put in almost a quart of oil. So far I've done the air filter, fuel filter, pcv valve, my shift solenoids/filter/fluid. My only code is a P076 tranny pressure code. The car needs plugs and wires which are getting done in a week and a half with ACDelco when my buddy pays me the money he owes me. Possibly O2 sensors after that. Lately I've been doing all city driving, avg mpg says 13.9. I've gotten 22-24 on the highway if I reset it before getting on the freeway.

I pulled the beauty cover off to check the FPR. I pulled the black hose off the nipple to test it, turned the key without starting a couple times, no fuel drip. The end/inside of the black hose smells like fuel I think. I wiggled a little on the "A" shaped clamp thing that holds the FPR in place and fuel sprayed out the bottom portion of the FPR where the greenish O-ring is. The O-ring wasn't seated on the FPR. Cleaned up the excess fuel, put the O-ring back on the FPR [ black plastic ring on first, green O-ring below that ] reseated the FPR and put clamp back on.

-Did I reseat the O ring correctly?

-I've seen mention of *two* O rings on the FPR, am I missing one? Where would it be?

-If there's no dripping fuel from the nipple, but the black hose smells like fuel, is the FPR bad?

-This morning the white smoke was gone. Could re-seating the FPR possibly have fixed my issue?

I found the procedure to test my injectors through the dash computer. Turning off each injector caused the car to idle rougher.

When I started the car this morning there was no white smoke at first. After a couple seconds I could see exhaust. Not nearly as white as it was before. The harsh smell was not present. It smelled smoother, lighter, and sweeter. Which makes me worry about the head gasket. Not sure if it's in my imagination or if I was just used to the harsh smell and this is normal. I measured the coolant level with a rolled up paper towel. When you take off the "radiator" cap there is a flat area that I assume the bottom of the cap rests on. My coolant level is roughly two inches below that flat surface, and coolant has not been added for a couple months since the air was purged and I topped it then.

-Is that the correct coolant level??

It's really nice out in Minneapolis today and I would like to check my injectors for leaks after work. I have the updated metalic looking fuel rail. It's not black. I saw reference to a bolt holding it on by the EGR, but I'm not sure what the EGR exactly is and where it's located. I'm not very confident in pulling the fuel rail out, I'm concerned about breaking something. A link to pictures or step by step directions would be much appreciated. I have the Chiltons repair book but not the factory service manual, have been hunting for one on Ebay.

When I had the beauty cover off I noticed one of the plug wires was not routed correctly and fixed it. The car seems to idle smoother now. I also noticed some brownish looking gunk in what I believe is called the valley behind the back injectors. It seems more built up towards the passenger side of the car. It looks like a fluid that didn't burn off cleanly. I can take pictures if that would help.

-any idea what that is, and where it came from? Could it possibly be fuel that leaked out of the FPR, or is it something like oil or coolant?

-is this the rear oil gasket thing that I've seen refered to as not worth fixing?

Thanks in advance for the help and for wading through my long post, and thanks for helping out a total newbie!

[Ranger]

If there's no dripping fuel from the nipple, but the black hose smells like fuel, is the FPR bad?

No. There is a rubber diaphragm in the FPR that separates the fuel side from the vacuum side. If the FPR is bad (leaky diaphragm), then unmetered fuel gets into the manifold via the vacuum line. Try your test again, but this time add vacuum to the FPR when the fuel system is pressurized. Use a hand held vacuum pump. If you don't have one, pull the other end of the vacuum hose and suck on it. If fuel comes out of the hose when you remove it from the FPR then the FPR is leaking when under pressure from the fuel side and vacuum from the vacuum side. If it is not leaking at the mount, then it is probably mounted correctly.

Is that the correct coolant level??

Yes.

[lothos]

If there's no dripping fuel from the nipple, but the black hose smells like fuel, is the FPR bad?

No. There is a rubber diaphragm in the FPR that separates the fuel side from the vacuum side. If the FPR is bad (leaky diaphragm), then unmetered fuel gets into the manifold via the vacuum line. Try your test again, but this time add vacuum to the FPR when the fuel system is pressurized. Use a hand held vacuum pump. If you don't have one, pull the other end of the vacuum hose and suck on it. If fuel comes out of the hose when you remove it from the FPR then the FPR is leaking when under pressure from the fuel side and vacuum from the vacuum side. If it is not leaking at the mount, then it is probably mounted correctly.

Is that the correct coolant level??

Yes.

Thank you for your reply.

It's reassuring that the coolant is at the correct level

I don't have a vacuum pump, so I turned the key on but did not start the car, and pulled the other end of the black hose. Sucked on it pretty good. It felt pretty weird to be making out with a cadillac I did not suck through any fuel, and when I pulled the hose end off the FPR there was no fuel coming out as well. The air I sucked did have a hint of fuel taste to it.

It's good to know that the FPR is probably seated correctly. Although Ive read on here that there are two O rings on it, would that mean the black plastic ring and the greenish rubber ring? Or am I overlooking one?

Regarding the fuel smell to the engine oil, is that a normal condition? Possibly just vapors and there's no actual fuel in there? The oil on the dipstick looks normal.

Could the spark plugs be causing the rich mixture and white smoke I get sometimes? I'm not sure if they've ever been changed and the car has almost 158k on it now. The ACDelco wires are kind of expensive and I'm waiting for my buddy to pay me back in a week and a half to do them. I've had a stumble on acceleration twice now that I've assumed to be caused by the plugs and wires. But by reading the forum I'm under the impression that the white smoke is caused by fuel dripping from somewhere, I'm not sure if it can drip from the plugs or not.

I guess the next step is to check the injectors? I've located the EGR and there's a bolt holding it on to the end of the fuel rail. I assume that's the correct bolt to pull in order to pull up the injectors?

Regarding the "gunk" in the area below the back fuel injectors, I took a look at it during the day today and it's not a wet looking sludge, it's more of a dry brownish dirt looking thing. I had a coolant leak that sprayed on the strut bar and the coils below it, maybe it got down in there?

[fivepointohman]

Just and FYI, the cadillac fuel rail recall will give you new fuel rails ( stainless steel ) and along with that a new FPR to go along with it as well and new injector O-rings. Its free of charge Via GM. That would eliminate FPR issues along with fuel leaks.

[lothos]

I'm assuming the car has already had the fuel rail recall done. The fuel rail doesn't appear to be the black plastic, it's more of a gold/silver color.

EDIT: Here's a picture I took of the gunk I was trying to describe behind the rear fuel injectors. That's the newer fuel rail, right?

http://i258.photobucket.com/albums/hh261/l...12/P4040007.jpg

[fivepointohman]

I'm assuming the car has already had the fuel rail recall done. The fuel rail doesn't appear to be the black plastic, it's more of a gold/silver color.

EDIT: Here's a picture I took of the gunk I was trying to describe behind the rear fuel injectors. That's the newer fuel rail, right?

http://i258.photobucket.com/albums/hh261/l...12/P4040007.jpg

Yes, the recall has been done on that car... That gunk is oil that is leaked out from the valve covers over time. A nice soaking of engine brite and good blast with a hose will clean that up.

[Ranger]

Yup, next step would be to check the injectors. That is the only other place that fuel can leak into the cylinders from and cause the condition you describe. If you have a leaky or stuck open injector, it will leak down after shut down. The fuel in the cylinder will eventually leak past the rings and into the crankcase, which would account for the fuel smell in the oil.

[lothos]

I'm assuming the car has already had the fuel rail recall done. The fuel rail doesn't appear to be the black plastic, it's more of a gold/silver color.

EDIT: Here's a picture I took of the gunk I was trying to describe behind the rear fuel injectors. That's the newer fuel rail, right?

<a href="http://i258.photobucket.com/albums/hh261/l...12/P4040007.jpg" target="_blank">http://i258.photobucket.com/albums/hh261/l...12/P4040007.jpg</a>

Yes, the recall has been done on that car... That gunk is oil that is leaked out from the valve covers over time. A nice soaking of engine brite and good blast with a hose will clean that up.

The valve cover? When I had the metal and rubber coolant hoses by the firewall replaced he told me that he had to take off the valve cover to reach it and the gasket was done then. That would fix the oil leak there, correct?

[lothos]

Yup, next step would be to check the injectors. That is the only other place that fuel can leak into the cylinders from and cause the condition you describe. If you have a leaky or stuck open injector, it will leak down after shut down. The fuel in the cylinder will eventually leak past the rings and into the crankcase, which would account for the fuel smell in the oil.

If I remember correctly from reading the forum here, there's a bolt on the EGR that holds the fuel rail down. I remove that and the fuel rail can be pulled up then? Is there anything I should watch out for while I'm doing this? Parts that can break, or anything like that? If I remember right there's a procedure I found on here for cleaning the EGR, I think I'll try to take care of that at the same time.

[Ranger]

Well it is actually a threaded stud with a nut on it holding the EGR valve down and the rail clamped to it. kind of a PITA. Other than that, I think there should be enough play to lift the rail after all the hold downs are removed.

[lothos]

OK, so I pulled the rail up today to check the injectors. I couldn't see anything dripping from any of them. Number 8 in the front right was resting on the top of the hole that the injector goes into, and there was a little bit of fluid where it was resting. So I'm guessing that one might be leaking. I didn't see any obvious dripping or anything though.

When I was putting the injectors back into the holes, the middle two on the front wouldn't go in nearly as easy as the others did. I ended up taking a rubber mallet and gently tapping them into place. Was that an ok thing to do?

Also I wasn't paying any attention for o-rings on the injectors, how possible is it that any of them fell off into the ports?

The car is running the same as it was before, if not a little better now. I tested the injectors through the dash computer and everything checked out ok.

[lothos]

Well, I was googling the fuel injector issue and I'm thinking maybe I shouldn't have tapped the two injectors in with a rubber mallet. Didn't actually hit the injectors, tapped on the metal fuel rail to seat them. Looks like there's a special O ring lube I can pick up. Hopefully I didn't harm the injectors.

It was colder out today, going to snow later. I got the white smoke and harsh smell on startup this morning. Can I assume the number 8 injector needs to be replaced, or should I pull them off again and check the O rings? Would new O rings possibly fix this?

And how likely is it that I could lose an O ring down the holes they slide into?

[lothos]

OK so the car was sitting all day at work. After work I got the white smoke and harsh smell again. There was also a rough idle. I stopped at Checker Auto and got some O rings and some white lithium grease. Going to take another look at everything hopefully tomorrow night.

Any suggestions? I think I'll take some paper towel and put them under the injectors before I turn the key, see if anything drips onto the paper towel.

[Ranger]

Did you pressurize the fuel system when you had the rail out to check the injectors?

[jomo924]

you say you had smelled bad exhaust like sulphur and there is lots of white smoke,,,well the white smoke is no doubt unburned fuel and the engine is running very very rich which would account for some fuel in the oil ( do an oil change asap) i would check for troubles codes that sulphur smell along with an overfueling condition might be a bad o2 sensor

[lothos]

Did you pressurize the fuel system when you had the rail out to check the injectors?

I believe so. I turned the key on but didn't start the car, just like I did when checking the FPR.

I got some white lithium grease and four sets of O rings at the parts store, so I'll see if any need to be replaced. The new O rings were really cheap and can be returned if I don't use them.

I'm going to try putting a paper towel under the injectors this time to see what drips.

If you have any other suggestions I'd appreciate it, this is obviously my first time doing anything like this.

[lothos]

you say you had smelled bad exhaust like sulphur and there is lots of white smoke,,,well the white smoke is no doubt unburned fuel and the engine is running very very rich which would account for some fuel in the oil ( do an oil change asap) i would check for troubles codes that sulphur smell along with an overfueling condition might be a bad o2 sensor

The O2 sensor is no doubt original. 158k miles now on a 95 STS. The O2 sensor has been on my list of maintenence to do after the plugs and wires. If I replace the sensor and it doesn't cure the problem, will that foul the new O2 sensor?

EDIT: Just read on here that non-oxygen sensor safe sealer can foul O2 sensors. The back valve cover gasket was replaced a couple months ago and I'm not sure what kind of sealer he used.

I'm trying to fix this problem before I do my plugs and wires (those might be original too) thinking that this rich condition might foul the plugs. I asked if bad plugs might be causing this but I think it got lost in the noise of my novel-sized first post

BTW there's no trouble code for anything other than P076 (tranny pressure control solenoid)

I'm also waiting to change my oil until I've done something to fix the problem, don't want to ruin the new oil as well. I topped it off a couple days ago which will hopefully help.

[lothos]

OK, I checked everything out again. Put some paper towels underneath the injectors this time. Turned the key, let the car sit for a couple minutes, turned it off and did it again. Checked the paper towels and it appears that one of the back injectors is leaking. The paper towel had a small circle of gas.

I'm going to order a fuel injector, spark plugs, wires and oxygen sensors tonight, probably from gmpartsdirect or rockauto.

Anyone know how many O2 sensors my 95 STS has?

The O rings on my injectors looked good. The ones I bought are the wrong size, they don't fit either o ring on the injectors They're going back tomorrow.

I'm going to drive the car as little as possible until it's fixed, and get an oil change immediately after the repair is done.

Thank you very much to everyone that helped me. I greatly appreciate it.

[lothos]

I've had a fuel smell from the exhaust that I contributed to the bad O2 sensors. Went to change it today, started the car to warm the exhaust manifold, and could smell fuel from the exhaust. Smelled the oil, sure enough I got fuel smell. Pulled the rail and tested, and the remanufactured injector I put in is leaking.

Did I get a bad injector, or is there another issue?

[lothos]

I called rock auto. Someone answered the phone right away, and within two minutes they told me they're shipping a new part out tomorrow.

I would definitely order from them again.

[winterset]

Test the injector before you put the fuel rail & such back on.

Is there a learn procedure or calibration that has to be run when installing a new injector?

[jackc]

Did I get a bad injector, or is there another issue?

I've received a bad reman injector from RA too. Sounds like their supplier has some quality control issues. RA also made it good for me with no hassles.....

[winterset]

To maintain Injectors, I would recommend 8oz of Marvel mystery oil in the gas tank at each fill up. I am not an advocate of addidatives in the oil/gas etc, but good lubrication never hurt anyone. I sometimes put 12oz, and I can swear I hear the engine run quieter & smoother following a treatement - this will lubricate the fuel pump & injectors. I have been doing this in all my cars for years. Just don't use fuel injector cleaner.

[lothos]

The replacement injector leaks from the nozzle also. I attached it to the rail and tested it this time, and it leaks. They're sending a third one out now. If I had to do this all over again I'd just buy the new ACDelco brand instead of this GB remanufactured injector. If I can grab some injectors from that junked car, and if the third one is leaking as well, I'm just going to ask for a refund.

Does the Marvel Mystery Oil really work that well when put in the gas tank? I've never heard of it, and I'm leary of putting in any additives after reading the forum here.

[Texas Jim]

Does the Marvel Mystery Oil really work that well when put in the gas tank? I've never heard of it, and I'm leary of putting in any additives after reading the forum here.

I have used it on occasion over the past 30 years or so.

Never used it at every tank. Maybe two or three times a year.

I have never had it hurt anything and like Winterset said... sometimes it does seem like it runs better. But that may or may not be all in my head.