Plug and Wire Replacement Question 1992 LT1

[JimC]

First post Everyone, please have mercy! I'll get a photo up soon.

I have a 1992 LT1 and I would like to perform basic service on it myself. I went out and bought the basics, then opened the hood. I can't believe how difficult it looks to replace the wires, and the plugs are no simple subject either! I was able to get 4 of the 8 and gave up. I just don't want to pull half the mechanics off the engine to get to the plugs and wires. Can you guys point me in the right direction, possibly some articles, on the easiest ways to go about this effort? I would assume many of the folks here find regular maintenance easy on this model and I don't want to re-invent the wheel. I have other vehicles I work on so I'm not green, just intimidated.

Working on sports cars is supposed to be fun. Replacing the plug wires on an LT1 does not look fun!

Signed, Down in the Dumps!

Thanks,

Jim

 

[Ken]

Welcome To The Corvette Action Center JimC!

Welcome to our family Jim.

As you have already discovered, the tight confines of the Corvette engine compartment make even the smallest of maintenance chores a nightmare sometimes to work on. Sometimes everything seems to be in plain view and easily accessible until you reach for it, or try to get a wrench on it. The spark plug wire routing is especially frustrating because of the way they are routed under the exhaust manifolds. The Optispark is another area of concern.

Hang in there and someone with an LT1 will be supplying you with enough detail to get you started.

Oh yeah, we LIKE photos too!

 

[qwall]

i know it's not the easiest thing to do, but as someone mentioned in 1 of the other threads, the mechanic said it'd be about $400 to change plugs and wires, which to me sounds too much. Like Ken said , someone will walk you thru it

welcome to

q

 

[robert kirk]

yea it's a pretty intense job. on the driver side the wires run under the ac and through the ps bracket. pass side the wires were pretty easy. i used a long pair of hooked nose needlenose pliers, grab the boot easy and with a little twist and pressure they seated up in the opti just fine. i found it impossable to do with my fingers. changing the plugs required a short 3/8 drive and deep well socket. on a couple i was able to use an extension and get them pretty easy, the others you have to be patient and work the socket, i will admit i lost some hide on the #8 plug but the rest were skin free. wait till you change the fuel filter you'll love that. it sits on the pass side between the exhaust and the fire wall. talk about tight. good luck robert

 

[Steve92LT1]

I'm doing mine as soon as we get some good weather and a day off at the same time. It looks tough on a few, but NOTHING like on an LT1 F-body. You can't even see those plugs and it took me 3 1/2" hours to do those. I'm thinking I might have to move some of the emissions (AIR) lines on the driver side to get to those couple back plugs.

Good Luck!
Steve

 

[vettn94]

It's defintetly not fun, especially the first time but Once you have done it you'll see it's really not that bad. Definetly not worth paying someone to do it, especially not $400 -lol.

The plugs are easy to get at except for #8 which is tricky.
If you remove the inner wheel well panels it helps, you can use and extension to get at the plugs easier that way.
Pass side wires are a cakewalk. You can reach down and pull them off the opti using your hand no problem. Drivers side wires are another story. First you'll need to take the belt off. Be careful of the temp sensor on the front of the block when you're using a belt removal tool, I usually just unplug it and it clears fine.
Then unbolt the ASR box, if I remember right there are 2 lower bolts attaching it to the inner wheel well panel and a third somewhere obvious. Once you get it unbolted just move it out of the way, I usally lay it on the battery or up near the firewall. Once you get the ASR box out of the way a whole new world opens up for you-lol.
Next I unbolt the AC compressor (4 bolts) and move it out of the way a little. Then I unbolted one of the pulleys, I want to say it was actually the tensioner pulley, it's been a while, but you'll see what is obviously in your way there and once you get that pulley off you can reach the opti on the dr. side.
I hope this helps a little, like I said I have done this a couple times now and when I did headers but my memory is terrible.

I have heard people say they got to the dr side (opti) from underneath the car. My hands aren't that big but I tried and just don't see how.

Just have some patience and plan on spending the better part of an afternoon.
good luck

 

[JimC]

Everyone,

Thanks for the advice. It looks like the DR side wires are going to be the handful I thought they would be. At least it doesn't need to be done often!

Again, the comments are appreciated and will be put to good use over the holidays!

Regards,

Jim Christian

 

[Steve92LT1]

Just finished mine.... yeah they are a major pain. #8 plug is horrible and #1 is kinda tricky. If your plugs are like mine (original), you'll need a breaker bar to get them loose. Man they were tight. I put a little anti-seize on the threads of the new ones so hopefully that wont happen again.

Also, yes I removed the inner wheel well panels (rearmost sections) on both sides. Without it, it would have been impossible on the driver side. I used long extensions to get at most of the plugs. I didn't however get the ASR box out of the way. I unbolted 3 bolts, but it was still kinda stuck from the hoses that were attached to the bottom bracket. That was ok though.

Good luck!
Steve

 

[Vettelt193]

I remember changing them on my '87, and the passenger side was hard, since the engine is offset. The driver side was a piece of cake.... On my LT1 I tried, and the passenger side is hard, and the driver side harder

I know one thing... if you have access to a lift, it is much easier to do the job with good under-car access, as well as topside access:eyerole

 

[rich95]

I have been reading in this thread that folks are removing the wheel well panels to access the plugs. This looks like a tough job in itself. Is this a real complicated procedure? On my 95, I thought I saw numerous things bolted to it. Not sure, I will have to look again.
rich95

 

[Steve92LT1]

Removal of the wheel well panels is really easy. You don't need to remove the whole thing, just the rear most section (between the a-arm and the back). The wheel well is multiple parts, look close and you will see. I have a 92 LT1 car. The weatherstripping just pulls off. There are 2 T-15 torx screws, 3 T-30 torx screws and about 5 or 6 10mm screws (1 10mm on the bottom and the rest are visible in the wheel well). On the driver side panel, there are also 2 7mm screws that hold a relay to the panel. Thats all there is involved to remove the panels. Not hard, just have to remove all the screws.

The removal of the plugs is the real task. They were REALLY tight, needing a breaker bar to get them loose. I didn't change my wires, because they looked brand new and were still perfectly pliable. I just cleaned the inside of the boots and reused them. The stock plugs, all but 1 had the pucks missing, so the gap measured about 68-70 thousandths, that isnt good. My 95 Z28 LT1 was the same way, with the large gap and the REALLY tight plugs.

Replacing the plugs seem to make the car idle/run even smoother. Samr results with the camaro. I used NGK TR55 plugs on the vette and they seem to work well so far.

Steve

 

[rich95]

Cool, thanks for the info. I just bought my 95 in Oct and I suspect that the car has the original plugs in it, so I have this unpleasent task ahead of me. I'll keep my breaker bar at the ready!
rich95

 

[Muddy]

I have a 92 and yeah it was not easy changing the plugs, I moved my ARS unit and the air pump vale assembly out of the way and removed the inner wheel panel on the driver side, this allowed me to get to all the plugs. The passenger side was not much of a problem, I did not have to remove anything except for a few layers of skin. If you have access to an air compressor blow out any dirt that may be trapped in the spark plug well before you remove the plugs. Because you have to screw the plugs back in kinda blind and any dirt could be pushed in to the cylinder. OH Yeah using a 3/8 square drive deep socket (as Robert mentioned) made life easier for me.

In fact my car has done almost 100K and I decided to change all the fluids and filters, man that was a nightmare.

I am with Robert on the “changing the fuel filter” thing, I don’t think it could be in a more inaccessible place.


Best of luck.

Muddy

 

[Corvette-Pilot]

This is what kills me with Corvettes (at least C4s)
The entire hood lifts up and exposes everything yet you still can't get at any of them :bang

I like my 97 RAM 4x4 in the sense that I can litteraly stand inside the engine compartment to work on it.
The one know big issue on this truck is the distributer cap.
Since the compartment was set up to take the V10 the V8 is way back so the cap is under the firewall !
You nearly have to drop the engine down to get at the cap.

Maybe these car designers should be forced to work on the car before approving it for production ! !

 

[RLD92]

I can't add alot other than to say a lift does help on the opti part of the wires It was a challenge on drivers side. I used a couple of long extensions together and unbolted asr and was able to get to plugs and wires without completely removing good luck.

 

[garycr14]

Plugs

I have replaced the plugs on my "94" with the Bosch +4. It was actually easier than I had expected. Pass side no problem, Driver side, once I removed the ASR box, it was no prob either. Hard to see the plugs, but just felt around a bit. It took about an hour for all 8. I haven't did the wires yet, but they are due. Getting to the opti spark will be a problem. I also will wait to see if anyone has a good idea.