Leaky injector

[tRustyK5]

I had what I assumed to be a small return line leak at two of the injectors recently. I replaced the return lines with new ones and new clamps...

I found one injector was slightly loose in the block so I snugged it up and cured one leak/forums/images/graemlins/confused.gif then tried the same on the last injector and still have a leak there.

I have two questions. Is this something injectors do when they go bad? Is there a bad seal or something? Secondly could this be a contributing factor to hard starting when it has sat for anything more than a few hours?

Rene

 

[arveetek]

I had a leaky injector on my truck last year. It was leaking between the injector body and base. It's supposed to come apart there, but I couldn't get it to budge. I ended up replacing it with a new injector (which only cost $24.95). I didn't notice any hard starting problems associated with the leak.

Casey

 

[RLBstein]

Your leaky injector could cause hard starting due to the fact if fuel can leak out, air can lead in. If you don't want to replace the injector the next easiest thing is to have it rebuilt by an injection shop, I think it cost me 7.00 each and they will do a "pop" test to see if they are functioning properly, and replace the seals.

 

[tRustyK5]

Thanks guys...I'll let you know if it helps the hard start problem.

Rene

 

[arveetek]

I kind of doubt that a leaking injector could cause a hard start, or introduce air into the system.

Here's my thinking: if the injector is only leaking when the engine is running, it's mostly likely leaking from the pressure side, which means the leak is a long way away from the injection pump. I don't see how air could work it's way into the pump from that distance. Air could get into the line, but that would mean air lock on only one cylinder, which should mean the motor should still start okay.

The injector could also be leaking on the return portion of the system, which again is a long way away from the pump. I would think that leaks in the return line of the system wouldn't allow air into the pressure side.

I have found most hard to start conditions are caused by problems between the high pressure injection pump and the fuel tank. Typically it's a bad fuel lift pump. How is your pump, tRusty? Are you running the standard mechanical lift pump? If so, is it the original, or new? I have found the lift pumps will leak down overnight and cause hard starting problems. I've replaced the fuel lift pump on every 6.2L I've ever owned for this reason. I had an '86 burb with 6.2L that would start fine as long as you didn't leave it sit for more than 3 days. Then it would get air locked. Replacing the pump fixed that one.

Casey

 

[Tybee]

Wheres it leaking from? And when you replace injectors I think your sopposed to replace the copper washers, seals or whatever there called around the nozzle base.

 

[tRustyK5]

Well I installed a brand new lift pump during the swap because the old one was FUBAR...unless I got a bad pump out of the box? The leak is gonna get fixed regardless...

Rene

 

[BlueBlazer]

I agree with what was said earlier about taking the injector to a pump shop. Make sure they test VOP (pop pressure), tip leakage, and excess return leakage.

 

[tRustyK5]

Is it OK to just replace the bad one with a rebuilt injector?

Rene

 

[BlueBlazer]

Yes. Just compare part numbers to make sure they are the same.

 

[tRustyK5]

Thanks Tyler /forums/images/graemlins/thumb.gif

Rene