I recently finished swapping a 2006 LQ4 into my 86 camaro. The engine is controlled by a Holley HP EFI system. When I was bleeding the clutch today I noticed that there was gas dripping from the drivers side exhaust pipe. The passenger side looks perfectly fine, spark plugs are good, headers are dry. The drivers side is soaked. I pulled the plugs and they are all damp and smell like gas.

I pulled off the whole driver side coil setup with the spark plug wires and am going to start testing the resistances. Does anyone have a better idea of what I should do to troubleshoot this? Thanks

 

Ya, look at fuel system, not the coils.
Somehow that whole bank of injectors isn't closing the pintle.

Also, you'll ruin the engine running it now. Drain all the oil and dry the cylinders.

 

How do you recommend drying the cylinders? Also, if the oil doesn't smell like gas does it still need to be replaced?

If I remember correctly, my holley harness has one harness that goes to all eight injectors. I would assume if the wiring is right for one side it would be right for the other as well.

I read you can test the injectors with a 9V battery. I may give that a try tomorrow and see if the injectors are stuck. If they check out, would I be able to check them with the engine running? What would damage the engine, just contaminated oil?

 

I imagine you can just leave the spark plugs out for a while. It doesn't need to be dry, just let it air out while you work on the problem.

Oil is cheap. Replace it after solving the problem. Some gas gets in the oil anyway. Just don't want a ton of it.

The biggest risk is injector sticking open and washing the cylinder walls with gasoline. It will displace oil and cause cylinder wear. If the engine is used and already well broken in with many miles then you can probably run for short time without issue while you're trying to fix the problem. If the engine is new then I wouldn't chance it. Proper break in is really important.

 

How did the engine run? If the coils were bad then engine would run rough or not at all if you lose too many cylinders. You'd also see it in the O2 sensor data logs.

All injectors get power from the same source, but the valves are controlled individually by the Holley ECM. It is highly unlikely to have the same defect with 4 injectors all at the same time. It's got to be a Holley issue.

 

I think the motor runs pretty smooth. I've just assumed to this point that any issues were tune related, which I'm learning as I go. There's also the vibration from the exhaust that makes it difficult to tell. I was able to drive it to Chicago, so its driving pretty well. I did notice my gas mileage is terrible, now I see why.

I called Holley earlier to ask them what they thought and the guy basically told me if the one side has too much fuel its an injector or engine problem and not their system. I thought maybe there was some significance to the fact that the side with the o2 had no problems, but he said with a balanced motor it should make no difference. I could call back tomorrow now that I know its not just one injector. I also found that a screwdriver can be used as a stethoscope to hear the injector opening and closing when the engines on. I was going to give that a try just to know exactly what the problem is.

 

So Holley wasn't any help, but I began thinking with my luck its going to be another ground issue. Sure enough the driver side cylinder head ground got a little loose causing no spark, or not as strong of a spark. Its a whole new car, I'm changing the oil now. Thanks again for your help.

 

Awesome you found it!

 

Yet again another ground issue is the root cause of a mystery problem. Glad you caught it