Changed Knock sensors now car is smoking

[ajciafre]

I changed my knock sensors and now my car is blowing smoke through the tail pipe. its gray thick and smells like its running rich. the car smell like fuel inside and it didn't start till the car warmed up. The coolant temp is running just under half and the car sounds good. well it sounded better when I first started it. I replace the number 4 injector as well thats the reason I did the KS. The car was missing before and I detect a slight miss now but it goes away if I let the car sit and restart. I'm thinking maybe the fuel filter but still not sure where all the smoke is coming from?

[BCC93QT]

Sounds like you mis-matched a hose or two when re-assembling. I think this is common but I am not sure which hose(s) they are. I'm sure someone will chime in

[ajciafre]

I'm gonna shoot myself if the plenum has to come back off. I hope someone knows what this is and hope I didnt damage anything. It starts right up still.

[OwnerCS]

How long has your car been sitting before you started it? Where are you located? Mine sat from early September past Thanksgiving one year and the suitcase muffler was full of water from condensation when I started it after repairs. It blew white looking steam from the exhaust until I had a muffler shop remove the suitcase muffler. I thought I had a blown head gasket there was so much moisture coming from the exhaust. When the guy cut the muffler off the car I could hear him yelling when the muffler hit the garage floor as it was full of water. Once I removed the suitcase muffler that was holding water, that ended my white smoke problem I think it takes a long time to burn off water built up in a suitcase muffler. I drove it on a 120 mile trip that didn't seem to phase the issue as I recall. I'm not saying that a hose may or may not be hooked up wrong, but I went through a lot of wasted time and money looking for a reason for coolant to be in my exhaust when it was just water that had built up in the suitcase muffler.

[ajciafre]

It sat for three weeks and I did plug up a hole near the front of the exhaust about two weeks before I did the repair on the injector and KS. It looked like a hole from the factory. maybe it is a drain for the exhaust? I wonder if I just try to drill a hole in the muffler and just plug it up with some JB weld couldn't hurt to try? I have been going over the FSM for the past hour if not longer. I have gone out and checked the connections and have yet to find a wrong one as I cut all of the line and replaced them as I re assembled. So all the cut marks matched up when the plenum went back on. I took off the lines that didn't fight me too much. The only line I didn't reconnect was to the fuel damper but I have the vacuum side capped off. I do hear a slight vacuum leak but when the car first started it felt and sounded better than it ever has. That would make sense that it doesn't do it right away, the exhaust probably needs to heat up first. It didn't seem to start doing it till the car warmed up a bit. Is that what was going on with yours?

[OwnerCS]

Three weeks is not all that long compared to the 3 months mine was out of commission. Since it was late November/December when mine started puffing steam, just the winter time temperature difference made it blow some white steam. Since the muffler was full of water it never stopped steaming after it warmed up in my case. It will depend on where you are located as to your current temperature and the possible condensation that has accumulated.

[ajciafre]

I live in southeast pa 30 min west of philly. We have had some heavy rains and its been humid, dont know if that would do it. I started it up again and it takes about 5 min to start puffing thick smoke. it comes on gradually starting from nothing to a faint smoke then progressively gets worse till its like a fog machine. smoke carries for at least 40 yards. It doesn't smell like oil. I know what that smells like. I hope I dont have to beat my brains out with this one.

[OwnerCS]

Have you lost any coolant since the smoking started?

[ajciafre]

I cant say for sure. I was scared to run it too long in fear I might damage something. I wonder if water could be drawn in from sitting on top of the intake maninifold. I never removed it before starting the car.

[Skibane]

The steam produced by condensation in the exhaust is white - not gray. It doesn't smell like the engine is running rich - It smells like...normal exhaust.

[ajciafre]

I will check on the color again. It was dark last . I was up till 5 am reading about what it could be. I'll see if I can get another set of eyes on it too.

[ajciafre]

Ok now that its light out the smoke looks a whitish gray and lingers around like oil but has a strong odor of fuel. It smells what a normal exhaust smells like but amplified 5 times. Im puzzeled. If you see it you would think it was burning oil like crazy. Its so weird. It starts faster end easier than ever before and no smoke at first the warmer the engine gets the more smoke it will produce. when I shut it off you can see smoke still seeping from the tail pipe.

[qship96]

Leaky fuel injector perhaps dumping fuel?

[ajciafre]

Is there way to diagnose this without removing the plenum?

[Q451990]

There is a leak-down test shown in the FSM, but if you replaced an injector, and now it's dumping fuel, it's a good bet you have a pinched lower o-ring. Did you lubricate it before installing the new injector?

Also, if it's one injector, I would think the smoke should be coming just from one pipe on the exhaust. Although everything joins together at the rear muffler, I'm pretty sure it's still separated internally. If it's the right side, that would point to something on the side of #4. Is your oil level higher than normal? That would point to gas in the oil.

If you have an injector dumping fuel into the engine, your instincts about damaging something are right... you run the risk of hydrolocking the engine if your problem gets worse.

Good luck!

Heath

[OwnerCS]

Heath - Would it be worth AJ's time to pull the #4 spark plug and #2 to it to see if one is wet and smells like fuel after shutdown as compared to one that shouldn't be wet? Or unplug the injectors at the harness so they won't open and allow the car to run, then spin the starter a few times. If a plug turns up wet that would indicate the leaking injector cylinder.

[Q451990]

I think the sparkplug test might just work... I think pulling the spark plug and then just turning the key on to prime the pump and listening for dripping or fuel flowing into that cylinder could work.

I seem to remember Q45Tech saying that the injector circuit in the ECU is easily damaged, so I don't know if I'd run it without being connected or otherwise mess with it.

Heath

[ajciafre]

Thank you Q. To tell you the truth I'm disabled at the moment and have had to rely on a friend to do the work for me. He put the injector in and did the rest of the job but I was right by his side the whole time. We used to work on cars together about 13-14 years ago. He did use some grease on the o ring of the injector. I did notice it seemed hard to go in and had to use the cap of the injector to push it down when he tightened the screw. I just remember that it didnt seem right to me. I see what you are saying about pulling a plug. Sounds like a good way to diagnose the problem. I suppose a leak down test is still in order. I have to get a pressure tester first. Thank you for your feedback. So far that sound like the best possible culprit. I don't think the plenum will have to come all the way off if that is the case. I can leave most of the lines connected and just lift the left front side of the plenum to get to the injector if need be. The smoke is also coming out of both pipes so Im assuming the muffler mixes both sides. Good point though. I think you are on to something. I will let you know what I figure out. Thanks again guys. I really appreciate it!
AJ

[Q451990]

It's pretty likely that he lubed the big upper o-ring, but not the small lower one. If it was that hard to get it to seat, I'm certainly leaning toward that being your problem. I used a small amount of motor oil on both the seals and mating surface in the rail on mine. The later service manuals actually suggest motor oil... some people use Vaseline or even KY Jelly. I have never figured out what was so special about jelly from Kentucky... always tasted kind of bland on toast