*** Replacing New Fuel Injectors---LEAKS

[95ZR1#418]

Hi All-

I had my stock '95 injectors reconditioned. They were all in excellent shape, cleaning made little difference(~ 5K miles on them). None leaked & everything within factory spec's. I also replaced all the "O" rings(From Kurt)as well as new "O" rings to the fuel block.

I just did the leak test as recommended in the service manual.Turn key on 2sec- turn off 10sec- then turn on & check for leaks anywhere. When I did this you could here the gas dripping, it seems all the secondaries on cyl #2,4,6,& 8 all were gushing. I think a couple on the other side also. Maybe 1 or 2 primaries slightly leaked.

I turned the injectors slightly, soaked up the gas out of the secondaries which pooled on top of the butterflies, then did the check again. This time only a couple secondaries & a primary leaked.

I'm holding off for now doing anything. Any comments, what the problem is???????

P.S. I got the injectors back about one month ago & left them set till today in their sealed packages.

Thanks, Bob :confused

 

[Hib Halverson]

Hi All-

I had my stock '95 injectors reconditioned. They were all in excellent shape, cleaning made little difference(~ 5K miles on them).
(snip)
I just did the leak test as recommended in the service manual.Turn key on 2sec- turn off 10sec- then turn on & check for leaks anywhere. When I did this you could here the gas dripping,
(snip)
I'm holding off for now doing anything. Any comments, what the problem is???????

First, know that there is no such thing as "reconditioned" OE injectors. They can be cleaned. They also can be matched as to flow rates. They cannot be disassembled and reconditioned using new parts.

If you had the injectors leak-tested and now you have some leaking, either the injector service shop did the testing wrong or, maybe, you have some injectors which are now rusted.

In any event, you need to either have the leakers replaced or maybe try cleaning them again.

If it were me, because the stock GM injectors aren't all that good anyway, I'd replace the whole set with Lucas/RC Engineering injectors.

RC Engineering is at www.rceng.com

 

[95ZR1#418]

Hi All-

After consulting with Marc Haibeck & Rich Jensen of Cruzin Performance(did the injector cleaning) the concensous was to get the car running, bottom line. There was agreement that the Multec injectors are very finicky especially after left sitting for a period of time as compared to any others. After doing the injector leak test 4-5 times, tapping on them and keeping paper towels within the IH to absorb any leakage it was down to about 3 leakers. They were wet to the touch(putting your finger down into the IH on the bottom surface of the injector).

I put it all back together and it immediately fired -up and idled like a million bucks. Shut it down after it fully warmed up and changed oil. Fired it up again & took it out on the town for a half hour of heavy secondary port exercise. I then restarted it several times from warm & cold starts-perfect run & idle.

From my information I found that this happens with these injectors but most people don't realize it because they completely put the engine back together without doing this leak test so, therefore they never knew of this problem and if the car started up for them it mended itself, although they may have some gas leakage into the oil. What I think could be serious is if the reassembly was incorrect & the car didn't start-up right away- you could get cylinders with 10-20 mls of gasoline in them just after one session of cranking.

So, if you remove the injectors for servicing and replace them(or any) do the leak check(in the service manual in the section on fuel system assembly/disassembly). Before you do this(with the plenum off) stuff paper towels into the IH ports to absorb any leakage. Repeat untill most if not all stop leaking then allow the system to depressurize, and put it back together to the point that when it starts you can let it run/and or drive it. If you think gas is into the oil, change it after a warm -up then drive it-open the 2ndaries.