90 ZR1: Oh crud, did I break it?

[GTOger]

Alright, now I just need to sift through some existing posts on the best injectors to get. I know better than to start that debate here!

[GTOger]

OK, I lied. I tried to find the definitive answer but couldn't. I need some advice for good injectors that will withstand ethanol and not break the bank. I found some on Ebay
http://cgi.ebay.com/ebaymotors/1990-...-/310271671038

I'm really not sure what "rebuilt" means in this case, however.

Suggestions / recommendations / warnings are appreciated!

[tccrab]

Originally Posted by GTOger

OK, I lied. I tried to find the definitive answer but couldn't. I need some advice for good injectors that will withstand ethanol and not break the bank. I found some on Ebay
http://cgi.ebay.com/ebaymotors/1990-...-/310271671038

I'm really not sure what "rebuilt" means in this case, however.

Suggestions / recommendations / warnings are appreciated!

From cheapest to most expensive:
FIC Rebuilds
Accel
RC Engineering
.
..
...
Original Multecs from GM (avoid at all costs)

Here's a link to Dynomites Solutions page:
All the info you'll need. Put on your reading cap.
http://www.zr1.net/forum/showthread.php?t=11619

I put Accels in my Z about 3 years go, still working fine.
I've read good things about FIC's, definitely the cheapest solution.
RC Engineering are pricey but are supposedly the best out there.
Stay away from the original Multecs, they were not engineered for fuels with ethanol. They are the most expensive and are absolutely guaranteed to fail.

Order up some plenum gaskets from Jerry's Gaskets, his are hands down the best out there and Jerry is really a nice guy.

Too bad you're not local, I'd gladly pull your Z into my garage and replace them for you.
It's not that difficult, but you do need to pay attention to details.
It's very busy under the Plenum, lots of things to mess up if you're not careful.

TomC
'Crabs

[GTOger]

So as I understand it, I will need to get these injectors:
http://www.corvetteinjectors.com/sho...p?productid=33

and this gasket kit:
http://jerrysgaskets.com/store2/root...roducts_id=459

I guess it could be a lot worse!

[A26B]

Jon's (FIC) injectors come with Viton o-ring seals already on the injectors. You could save some $'s by buying the gasket/seal kit items separately and omitting PN 17112222-24V.

Gaskets & seals included in this kit are as follows;

PN 10168684 Gasket Set, Intake Plenum
PN 14104675-V Seal Set, Fuel Feed & Return Pipe (VITON-A)
PN 17112222-24V Seal Set, U-Primary & Secondary Inj & L-Secondary Inj (VITON-A)
PN 10067600-V Seal Set, L-Primary Inj (VITON-A)

There is a Tech Data Sheet on the web site regarding replacement of the lower primary o-ring seals, PN 10067600.
http://jerrysgaskets.com/store2/root...roducts_id=446

Lube all of the o-rings with a light coat of engine oil before re-installing the injectors. Makes assembly a lot easier and protects the o-rings from damage.

No sealant or adhesive required on the plenum gaskets. Clean & degrease the gasket surfaces is all that is required.

Lay the gaskets on the injector housings to get them oriented properly, then take the gaskets off and set aside (lay on the windshield is good). When the plenum is ready to be bolted down, raise each side of the plenum just enough to slide the plenum gaskets in place. Hand start all the bolts and tighten in sequence & torque.

There are some maintenance items you should perform while the plenum is off. Lots of great pictoral posts available here in the forum. http://www.zr1.net/forum/showthread.php?t=7614
For example;
1. Tighten all injector housing bolts
2. Tighten Crankcase Ventilation (PCV) Box bolts
3. Check secondary vacuum lines for leaks

[Paul Workman]

Now aren't ya glad ya didn't crank it before pulling the plugs?

And, whata relief! (Not a head gasket, I mean!)

You'll want to change oil and filter before venturing out again. I think most of us are following Marc Haibeck's recommendation and using Amsoil AMO 10-40; it has the "right stuff" in it for our flat tappet cams.

That #8 plug... I bought a plug socket with the built-in knuckle on top. To that I installed a 2-1/2" extension and taped the two pieces together to keep them from parting when extracting the socket from the plugs. Then, the socket will slip into the #8 and the knuckle allows the extension to follow right in, leaving the end of the extension peeking over the top of the hole when the socket is seated over the plug. I have a swivel-head ratchet that easily slips onto the end of the extension, and after torque is broken, the wrench comes off and I can hand turn the plug out. (Don't forget to put a little anti-seize lube on the plugs before installing them. Ya don't want them to seize and possibly damage the aluminum threads next time you extract them.)

FWIW, I installed new Accel injectors about a month ago. Oh, what a difference it made...Shweeeeet!

Glad you found your gremlin. You can put that behind you for and other dozen years or so!

P.

[Kevin]

Originally Posted by GTOger

OK, Update.... first of all, thank you for all the follow-ups and it's not that I've been ignoring you, but I got nasty sick on Friday and was down for most of the weekend. I dragged my sniffling self to work this morning just 'cause I didn't really have a choice. Now I'm feeling better so it's time to get the ZR1 feeling better!

NOW... for the excitement... This morning I came downstairs after getting ready for work and the wife says "it smells like gasoline down here". Being stuffed up still, I took her word for it. Until I got to the back hall and sure enough that was gasoline I smelled. I opened the garage door and it was really strong. Looked around under the car and found no puddles. Had to go to work.

Came home tonight & I managed to get all the plugs out except for 8. I'll go back and search for all the tips on how to get at 8, but what was GM thinking there?!

I compared all the plugs and they appear original (almost 28k miles on the car). #5 looks very fouled.

I bumped the starter a few times and watched for water to burble out one of the cylinders. When it hit #5, a geyser shot from the engine to the garage wall... on the far side of a 3 car garage! And it was gasoline.

I made another revolution with the starter and got the same result with slightly less gasoline bursting out. I got little "poofs" out of the others.

So now I'm thinking it's probably NOT water in there, but unburned fuel making its way out the exhaust valves and burning/evaporating off the inside of the hot exhaust, and that was the smoke I was seeing. Wouldn't that say "bad injector" to you? In which case, isn't that a big relief vs. it being a head gasket?

Whadya think?

if you think that #8 is bad on the lt5 you've never had an L98 or LT1/4 those are a nightmare. I think I still have scares on my hands from my L98. I haven't really been following injectors recently, but I need to. I know that RC used to be the standard for our cars, no idea who makes the best value for money now

[GTOger]

Oh, I had an old LT1 Trans Am, but got rid of it before it was close to needing plugs. Yech.

Thanks for all the help and input. Have I mentioned... This board ROCKS!

I've ordered some injectors from Jon and some gaskets & O-rings from Jerry. I'll stock up on some oil & filters and we'll get ready to go to town on this bad boy. Hopefully by next week I'll be back kicking some asphalt!

[VetteMed]

Glad to hear that things are looking up!

[tf95ZR1]

After MANY years following the LT-5, it's AMAZING how many
times the problem is faulty injectors. It seems like this is the
weak link! And being underneath the plenum, the trapped heat must
add to the stress. I wonder if another design would be better?
Hey, how about a carburetor on top of the engine! What a concept!