90 ZR1: Oh crud, did I break it?

[tomtom72]

I didn't see that picture.

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

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

[tomtom72]

Sorry Chris. I'm battin' 1000 tonight.

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

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?

[GTOger]

Originally Posted by tomtom72

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

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".

Worse, though, I could have blown up the garage if something was sparking in the vacuum. 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.

[tomtom72]

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. 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.


Tom

[sammy]

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 ???

[Paul Workman]

Originally Posted by GTOger

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.

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!! 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).

Originally Posted by GTOger

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.

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.

[Hammer]

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

[Pete]

Originally Posted by sammy

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 ???

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

[GTOger]

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

We're back on the road! WOOT!

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!

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?

Merry Christmas, y'all.

[Nacho_ZR1]

Originally Posted by GTOger

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

We're back on the road! WOOT!

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!

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?

Merry Christmas, y'all.

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