Issues after changing connectors...

[lvdisturbed1]

I have a 1990 TT and after having random misfires in one of the cylinders due to the coil pack connectors being cracked and brittle I decided to replace them and the fuel injector plugs. Ran it for a few days, but had a nagging feeling i was still missing a cylinder, so pulled each coil pack connector one by one to test. Lo and behold, one did nothing. Turns out I was a s*** and didn't wire it properly (middle and right wires switched) so I redid it and retested. It worked! Oh the joy! Unfortunately my victory was cut short.

I started smelling fuel, and noticed smoke coming from my exhaust. I quickly turned the car off and checked all the connectors again, all seemed well, so I tried starting the car again. Still had the problem. I put a screwdriver on all the injectors and heard them ticking along, then tested the resistance and they were still within spec. It was shortly after this I noticed smoke coming from somewhere around the driver side coil packs. I shut the car off again, and investigated the source noticing it smelled of burnt rubber. I couldn't discern the source of the smoke.

I am currently stumped. Any help or suggestions would be great. All cylinders seem to be working. Pulling the coil pack connectors individually brings a noticeable change, and the injectors are ticking and within spec. What could it be?!

Edit: I should note that the smoke from the exhaust is what smells like fuel.

[ThisIsSparTTa]

Was your bad cylinder #6? Its easy to swap it with the 02 connector. I did, and was stumped for a while. You can tell because one of the 02 wires will be be coax, and none of the CP ones are.

[lvdisturbed1]

No it was cylinder 4 that was miswired originally.

After some more digging, it is plausible that it has nothing to do with the connectors at all. Could be blown head gasket, or maybe blown turbo. Why it started after messing with the connectors, I'll never guess. Didn't notice the smoking when I was on my way home from work.

As for which one is the issue, I'm not too sure. The smoke looks white, but when it hits the light it has a blueish tinge to it. It doesn't smell sweet, like it would be coolant, but smells very rich. On cold starts, it doesn't smoke until it starts warming up some. Actually come to think of it, the smoking under the hood doesn't start until the car has warmed up some as well. Maybe burning oil? Oil on the dipstick looks good, with no visible water beading.

I am going to do a compression test tomorrow. I work grave and need sleep. Post suggestions if you have any!

[ThisIsSparTTa]

I don't think a compression test will hurt, but I believe in this case you will need a leakdown tester if you think the headgasket is done.

[lvdisturbed1]

I decided to give her a spin down the street to determine if it would be safe to drive to a shop 3-4 miles out. As expected, heavy smoke out the tailpipes. I pulled over when I saw a little smoke from the hood again. Fire extinguisher in hand, I investigated. Still couldn't determine the source, but I believe its oil. Not happy with the short trip, I decided to head back home. As I park, I discover the smoking from the tailpipe subsiding. Curious, I leave the car running for a bit. I pop open the hood, and the smoke from the engine bay was almost gone as well.

Perplexed, I figured I would wait a few hours and let the engine cool down again (from normal operating temp, it wasn't overheating). After 2 1/2 hours, I start her up again. This time no smoke out the tailpipe, and no noticeable smoke from engine bay. I figured it was worth another shot driving, so I went around the block a few times. Still no smoke, and running better than before I had changed the connectors.

Theory time. The car was definitely driving better. It had a little more power than before, so it is possible I was running it on 5 cylinders for awhile and didn't know it. There may be a small valve cover leak in that cylinder that wasn't running, and after changing out all the brittle connectors, it burned off the oil that accumulated now that it is running again. It took that short trip to burn out the oil in the cylinder, and now its good. Plausible?

If that was my issue, I'll get the valve cover gaskets redone soon. I may as well upgrade to the newer style injectors when I do the plenum pull. I'll update in a few days to report how the car is running.

[z32loverboy]

I would still compression test and leakdown test. They're not hard to do and they'll for sure tell you how healthy the motor is. Then eliminate things from there. I think the excess oil burning off is plausible but I would have done those tests myself. I check four things to start with: 1) Injectors 2) Coilpacks/Spark Plugs 3) Compression 4)Leakdown. It's almost always something to do with those.