Problems After Injector Replacement

[BLUMAX]

Well I got all the injectors replaced, overall not to bad a job, just time consuming. Now that the the truck is running it runs good, seems to have a little extra pep, just that sometimes it seems to be a little bit rougher at idle. No smoke when driving, after it comes up off of idle it seems to smooth out. Tonight I was poking around, checked the oil, had a funny feeling, drained some oil from the oil pan, and it appears there's fuel again! Now when I changed the injectors I also changed the oil, which had about 3qts extra come out, almost 14 qts total, and it was obvious there was fuel in it. I only have about 250 miles on these injectors and already looks like fuel in the oil. Is there anyway I just need to drain and fill again, any possibility fuel was still in the system somewhere when I changed it? Wishful thinkin'. I followed all the instructions, double checked the torque values on everything, everything seemed to go back together just fine. And this rough idle, is there any tweeking you have to do to new injectors, cuz I just replaced them. I don't have a ODB scanner to check for any codes, so another question will a basic scanner check for most codes, and any recommendations on which one to get without breaking the bank? I've seen a couple basic looking ones between $100-$175, I just don't know anything about them. As you can imagine I'm a bit frustrated.

[DmaxMaverick]

If your SES lamp isn't on, you don't have any significant codes to read.

It is possible there could have been some fuel still in the oil from the previous contamination. Changing the oil can only help, at this point. Measure the volume and compare with how much you put in.

If you installed late build injectors, and are only seeing fuel in the oil, it is likely one, or more, fuel return line has cracked, or a banjo fitting has failed to seal (rare, but it happens). If it is enough of a leak, you may be able to see it with the top valve cover off. The same applies with the HP lines, but extra caution is due here. The return is low/no pressure, but the HP lines have enough pressure, even at idle, to sever fingers, among other bad things, if there is a leak. A HP leak may only appear as a fog or "smoke". Use a wood dowel to check for leaks. Never your fingers!

Without being able to check balance rates and PWM, it is difficult to diagnose a rough idle. If the engine is not near operating temp, the idle may be rough, as the cylinder balance routine is not in effect. This is normal, in most cases. If you don't have an obvious knock or smoke, the injectors are not suspect, at this time. If the oil level has increased (from fuel contamination), it will cause a rough idle, and eventually dump the crankcase contents out the PCV.

If you reused your old HP fuel lines, contamination from them is a possibility, and you may have a fouled injector. This depends on your attention to cleanliness and preparation during R/R.

Change the oil. If the crankcase volume is the same as what you put in, it's probably residual contamination. If the volume is more, you have a leak. Take one step at a time.

[More Power]

I agree with Greg. If there is fuel in oil after the injector replacement, fixing it will be a whole lot easier than what you went through changing the injectors because it's most likely a leaking return line or less likely a high pressure line.

Where did you get the injectors? If they were from a reputable shop, you should be OK there.

Jim

[BLUMAX]

Thanks guys, I did install what I guess are late build injectors that I got from Merchants Automotive according to their site. I reused all the low/high press fuel lines after cleaning them (yes very gently) they had minimal corrosion/rust on the high press lines where they connect to the injector like others have talked about, but l thoght they llooked really good. Cleanliness was pretty strict (I'm an aircraft mechanic by trade not that that means anything, we all have bad days), things covered/capped/plugged, all the fuel lines were cleaned with parts cleaner then allowed to dry before installation. The published torque values were used and double checked on injectors, fuel lines, valve covers etc. Guess I'll pull the valve covers and check for fuel leaks, just wasn't sure with all the "stuff" that has to be removed to access them if it would be possible to temporairly hook-up enough, especially the coolant lines/tubing to be able to start the thing. With all thats involved to try and start it opened up like that, do you think it would be wise to just replace the fuel lines since I have to re-open everything? The other questions is if i took it to a shop would they be able to pin point which one could be leaking by checking balance rates and PWM (don't know what that is)?

Like I mentioned the idle roughness is fairly minor and its at all engine temps. No noticable engine knock, no smoke, in fact seems more "perky" after the injector change. So sounds like I need to chase down a leaking connection, my back will love that!

[Kennedy]

Did you get genuine GM/Bosch remans in white boxes?

Any leaks should be return side leaks as high pressure leaks come up the line by design.