Re: 90 ZR1: Oh crud, did I break it?
 

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! :)

Re: 90 ZR1: Oh crud, did I break it?
 

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!

Re: 90 ZR1: Oh crud, did I break it?
 

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

Re: 90 ZR1: Oh crud, did I break it?
 

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!

Re: 90 ZR1: Oh crud, did I break it?
 

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.

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

Re: 90 ZR1: Oh crud, did I break it?
 

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!:thumbsup:

P.

Re: 90 ZR1: Oh crud, did I break it?
 

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

Re: 90 ZR1: Oh crud, did I break it?
 

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!

Re: 90 ZR1: Oh crud, did I break it?
 

Glad to hear that things are looking up!

Re: 90 ZR1: Oh crud, did I break it?
 

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!

Re: 90 ZR1: Oh crud, did I break it?
 

I've never used Amsoil in anything. Not because I don't like the product, but for my applications haven't "needed" the product enough to deal with the hassle of working through their MLM network.

However, I now find it can be ordered online, and it's roughly half the price of the comparable Mobil 1 Racing oil (which also contains the cat-busting, tappet-saving zinc additives). Maybe it's worth giving the Amsoil a shot.

Thanks for the tip.

Re: 90 ZR1: Oh crud, did I break it?
 

I also wonder if using a more modern design might be bette? Fuel injectors have come a long way since the early 90's. Even if you had to change connectors, having greater injector reliability would be worth it to some.

peace
Hog

Re: 90 ZR1: Oh crud, did I break it?
 

Well, yeah, technology improves, and has improved; the stainless Accel injectors as an example. But, we're talking about 20 year old injectors with a known problem with alcohol. But, a carburator? Oh, really now! Maybe for a drag or dedicated track car...maybe. But, my wife has a carb'ed Vette, and I can tell ya from a performance point of view, temperature/altitude/humidity/heat soaking/choke settings/gas mileage(!), I never wanna go back to carbs!

Just a major 20-year tune up: Install new injectors, yank the secondaries, re-build the starter, change plugs, wires, and coils and ya should be all set for another 20 years!:dancing

P.

Re: 90 ZR1: Oh crud, did I break it?
 

Hi Race Fans.
OK, tonight the wife and I got familiar with the plenum removal technique. It's off. Hooray. But I'm afraid I'm in trouble now.

http://robin.virtbiz.com/cg/ZR1 - plenum-off-uhoh.jpg

If you can see from the pic (it's hard to get a good shot), there's water in one of them there holes. How bad is that?

Re: 90 ZR1: Oh crud, did I break it?
 

Can't see at all, but it's fairly common to have some drippage from removing the plenum. I would say if there's standing water, it's a problem. But if it's just water drops in the hole, wipe it out and reassemble. GL

Re: 90 ZR1: Oh crud, did I break it?
 

Hey John
Oh no... this is no droplet collection. It's standing water. Maybe this is a better pic:
http://robin.virtbiz.com/cg/water-in-port.jpg

So tell me: how screwed am I?

Re: 90 ZR1: Oh crud, did I break it?
 

Hi Roger, the good part is that the water stayed in the hole and didn't go any where else.....pull that plug and stick a clean rag down to see if any got to the cylinder.

Sorry, I'm behind on this saga so bring me up to speed. You were not running the motor right? You had just done a few crank overs with the plugs out to see if anything shot out...like coolant or in your case gas. Right?

My guess is that after buttoning up after the last plenum pull you tore a gasket...any sign of that on the plenum gasket from that side?

Oh, sorry, use a rag or paper towels to soak up that coolant as much as possible. The I would carefully pull that I/H so I could see the condition of the I/H to head gasket...that may have a tell tale as to where & how the coolant got into that port. Check me on this thought, that is a secondary port, I think? God bless the secondary port T- blades, maybe.

:cheers:
Tom

Re: 90 ZR1: Oh crud, did I break it?
 

It's not good especially since there isn't a source of coolant nearby. I can understand 1-3 or 2-4, but 6? Use a turkey baster to pull coolant if that's what it is. Get a coolant system pressure tester and see if you can determine where leak is coming from.

Re: 90 ZR1: Oh crud, did I break it?
 

Hey Tom
Actually, I'm Chris. But Roger works I suppose. Or Clarence or Victor. Or Ted Striker. :)

Long story short... driving home from Thanksgiving, car started running like something brown and stinky. Appeared to have white smoke. Thought I smelled glycol. Assumed the worst, then started thinking maybe it's just a bad injector. Plugs 3 and 5 are completely fouled. 7 & 8 appeared oily. No water appeared to shoot out when I bumped the ignition with the plugs out, but a bunch of gas did come flying out of 3. Like... a bunch.

This evening we pulled the plenum and found this little swimming pool in one of the IH ports. So here we are.

I'll try and get the IH off tomorrow and see what I can see. I note that even though I tried to be careful with the plenum gaskets, one of them just came to pieces. Guess I'll be hitting up Jerry again for IH to head gaskets.

If the port towards the back of the car is the secondary, then yes, this is secondary #5.

Re: 90 ZR1: Oh crud, did I break it?
 

It's actually #5, but same difference, I guess. I'll get it cleaned out, alright.

Re: 90 ZR1: Oh crud, did I break it?
 

:o I didn't see that picture.

Hey Dom:wave:, ain't that #5 secondary? Yea, there isn't any coolant passage close to that cylinder.

Crack somewhere? In the I/H? I hope.

Re: 90 ZR1: Oh crud, did I break it?
 

:o Sorry Chris. I'm battin' 1000 tonight.:o

Do as Dom suggests. I should have read thru the entire thread before posting up. I apologize. :o

I can't quite figure how coolant gets that far back to flood the secondary port on an I/H unless there is a crack or a bad head gasket ( I hope not ).

The plenum gasket that fell apart was from that side of the plenum, the side with the coolant in #5 port?

Re: 90 ZR1: Oh crud, did I break it?
 

Actually, it was the other side - the passenger side - that went to pieces.

But HOLD THE PHONE. As suggested I went back out to clean the port. Since it was just glycol, I used the trusty little shop-vac. That might have been a mistake. I think it was actually gasoline in there.

In hindsight, now I've destroyed the "evidence". :mad:

Worse, though, I could have blown up the garage if something was sparking in the vacuum. [-X I really should have known better. Kids, please learn from my stupidity.

However, after kicking myself (easier said than done, BTW) I fished around in the port with a rag and my finger. The sniff test says gasoline, gasoline, gasoline. There's a little drip of coolant where I pulled the plenum off. That smells like coolant. The port doesn't smell at all like coolant.

I went back and looked at the plugs again. None of them look "steam cleaned". #5 is filthy black, fouled really bad.

So I thought it was coolant in there just by the looks of it. But maybe that was just the lighting.

This is a roller-coaster for sure.

Alright, if I promise to quit being stupid, what do you think my next move ought to be? I'm really hoping for a good outcome here.

Re: 90 ZR1: Oh crud, did I break it?
 

Okay Chris, I like the smell of gas .... at least in this situation really bad injectors are waaaaay better than a crack in a head or some other expensive place!

Root around in the shop vac's tank and see if you can see anything & or smell anything. That would cinch the deal on the liquid being gas.

I feel much better for you now.:handshak: Order up some gaskets from Jerry and order up some injectors of your choice. Just one other thing, humor me I'm old & senile...that's my excuse! Check the fuel pressure regulator and it's hose for liquid gas in the hose or in the dome of the regulator....gas in either place = replace the F/P regulator.

One thing I would want Dom or Pete or Jerry or one of the other guys that know stuff is an opinion on with that much fuel being dumped can you hydro-lock a cylinder with gas????? I do not know the answer to that question....I would only be guessing.

:cheers:
Tom

Re: 90 ZR1: Oh crud, did I break it?
 

if i remember right you could ck the injectors even though the plenum is off. just keep the fuel system connected pull the injectors out of the housings rut a towel over the motor have the injectors on top of the towel and turn the key on for 2 sec and then off you should see the leaky injector if its that. pete isnt this ok to do ???

Re: 90 ZR1: Oh crud, did I break it?
 

It's always best to troubleshoot one problem at a time, Chris: divide and eliminate! Otherwise it can get a bit overwhelming and easy to become distracted and go off on tangents!! :icon_boun I'm never in favor of changing stuff till the problem goes away (e.g. many auto "repair" shops, including some dealers!), and commend you for testing. But, I sense you're having an issue with pulling the trigger. At some point enough is enough.

OK...First things first: the most obvious...Let's review:

• With the plugs out (sans #8) cranking resulted in fuel squirting out of #5. (Strike One)
• Add to that #5 plug was really fouled and NOT "steam cleaned" in appearance. Strike Two)
• Then you have liquid that smells like "gasoline, gasoline, gasoline" pooling in #5 secondary. (Strike Three!).

Given those findings, and keeping in mind the well established issues with those injectors in the presence of alcohol...I'd say that was enough to justify replacing the injectors. Yeah, there are even more tests you could do, but I recommend you replace the injectors and both the IH and plenum gaskets before becoming distracted with any other items (that may or may not be at issue too).

Besides taking a chill pill? ;)

With the new injectors installed, and before putting the plenum back on, you could do a fuel pressure leak down test - even brand new injectors have occasional "infant mortality". (You can get a fuel pressure test kit at AutoZone and if you take it back, you get your security deposit back and net no-charge for the rental!). If all is OK now, then you can move onto renting a coolant pressure test kit.

I'm going to guess and say (hope) you don't have a coolant leak. However, having installed new gaskets, there's no time like the present to test for leaks. Again at AutoZone you can rent a coolant pressure test kit (as suggested) and check for leaks. With new IH and plenum gaskets you will have eliminated the most likely sources for any leaks, and you will likely be back on the road soon. Again...I would change oil and filter before heading out again to avoid problems caused by fuel contamination in the oil.

Keep us posted.

P.

Re: 90 ZR1: Oh crud, did I break it?
 

Chris,
I'll bow out here as you have people helping you that are far more knowledable about the LT5 than me. My experience is general in nature and these guys have been around the LT5 internals before. GL

Re: 90 ZR1: Oh crud, did I break it?
 

Yeap.

That kind of water you might have a leaky plenum or IH gasket or head gasket these are the only ways to get water in the cylinders.

If you were cranking it, injectors will keep firing unless you go WOT with TPS connected.


Pete

Re: 90 ZR1: Oh crud, did I break it?
 

Well... Santa Claus came early to the GTOger Garage...


I can't thank you guys enough for the advice, support, and general camaraderie. I've had a lot of cars in my day from pretty much every continent known for car making. I've even had a C5 vette. Nothing compares to the ZR1 community. Not close.

In case anybody is wondering, it was injectors. The #5 & #7 primary injectors look like they've been leaking for a while, based on the fouling of the plugs. I got a new set of injectors from FIC and gaskets from Jerry's Gaskets. Both vendors shipped very quickly and I found the parts to be of good quality.

My wife and I spent one evening tearing down, removing the plenum, pulling the plugs, etc. Man... they sure do cram it in that engine compartment. I guess the main concern was not ease of servicing! :icon_scra

Unfortunately we had to wait a couple of weeks to put it back together due to other pressing business. So this evening we started putting everything together and I'm happy to report the Z fired right up.

There was a bit of a buildup of unburned fuel left in the exhaust, apparently, because it burned off for a bit (smoke out the tailpipes). I watched all gauges and kept an ear peeled for funny noises. She just purred like a kitten. Once I was sure there was plenty of coolant and all the pressures & temps looked normal I gingerly headed out for a spin around the block. Which turned to another. And another, this time faster. Next time put my foot into it a bit. Then I turned on the secondaries. Yee haw!

All the unspent fuel did burn off and now she's running clean. And she's running MUCH smoother than ever before.

Tomorrow: oil change.

Thanks again to everybody who posted here. I'm really proud to be a part of this community.

PS: do I get a bonus rating on my avatar now for having passed the ritual of a plenum pull? :blahblah:

Merry Christmas, y'all.

Re: 90 ZR1: Oh crud, did I break it?
 

CONGRATS! Perhaps a friendly run on the dyno will be on the agenda sometime soon :icon_boun

Re: 90 ZR1: Oh crud, did I break it?
 

Good thread, you gotta love happy endings. :thumbsup: The more I read about those injectors the more I think I should just tear mine apart and replace them before we have warm weather. :rolleyes: