In bartering storage for a vehicle, I find myself having to change the distrib cap, rotor and "shield" on a '94 CHEVY CAPRICE with the 5.7L engine. The parts are HUGE, and include a little socket and "star" wrenches to do the replacement. Then he tells me it's just above the harmonic balancer and leblow the water pump: at the very front of the engine.
Now, I've only briegfly looked at this once, and recall not much room there. Any hints/shortcuts./ things to look out for FEEL for while doing this. I think feel is the operative term. I can't believe where it's located...
Any advice would be appreciated.
BEHIND the water pump is almost more accurate.
GET IT in the air and do it from underneath IIRC.
I once owned a 94 Caprice with the same engine. You may get by with just plug wires. IIRC plug wires fail three times as often as caps and rotors. This is a very unpleasant task but it aint rocket science, clear a whole day on your calender and embrace the suck. On a happier note a well tuned LT1 Will bring a smile to your face.
pull the water pump to do it. just don't forget new gaskets for the pump. It's not terrible once the pump is out of the way IIRC.
The water pump needs to come off. The balancer too, but its just a bolt-on.
Then your job is easy... assuming you're not doing plug wires. They suck.
wow that thing looks retarded. so that's what you guys were talking about getting wet and failing with a leaky waterpump huh...
i suppose it is really compact though so helping you stuff it under the cowl of something small.
Can be done from below without puling the water pump - remove the serp, unbolt the crank pulley, replace. I prefer this approach to removing the water pump, unless you want to go ahead and change it while you're in there, which may be a good idea if the reason the Opti died was a leaking water pump. Edit - Curtis posted while I made a sandwich. Thanks!
Thank you Lord for for letting me buy a 93 Roadmaster with a normal distributor. I thought it was a PITA to change the cap and rotor on it until I saw the above.
Wow, I love the simplicity and directness of the design, but yeah working on it is a pain. Interesting though, never noticed that on the LT
I thought the owner was out of his mind when he told me where the distrib was. Yeah, sure I thought....why can't this E36 M3 happen in the spring/fall. NO. This weekend, at least I can get half of the car in his garage. Damn cap, rotor and wires were about $140....I'm NOT pulling the pump...I gotta get a tool for the serpentine belt, and then unbolt the crank pulley--which has never been off in 120Kmiles or so...this is gonna be fun.
Before starting this, though, the water pump area will go a throrough going over. I don't want to spend one day putting in the new rotor, then a month later get a call saying "there's a drip/leak/overheating...."
Hobbled by IE6, so, you sure the pulley has to come off?
Yeah, I'll suck it up and do it.
Thankfully the owner has good floor jacks and stands. Sunday will be interesting.
So much for "easy work/barter" storage. To be fair, he had no idea it was goiing to be such a PIA. I replaced a good part of my Protege's rusted exhaust, two days ago, on the ground, 28 degrees and 20-30mph gusts....
I wonder what a shop would charge for this....
Just get a 93 intake and some gaskets, drop a distributor into the hole, and eliminate the craziness.
Curtis, thanks for the diagrams, they will come in handy.
I'll take my time, pay attention, and simply do it.
I just find it hard to believe GM would bury such a normal maintenance item in such an awkward, deep-recesses of the engine.
Ranger50 wrote:
Just get a 93 intake and some gaskets, drop a distributor into the hole, and eliminate the craziness.
That's interesting! Although, this was bought as a winter beater, and he's already got the parts. Although I will bring this up for easy of maintenance for next winter. Though the plan now is to sell it in the spring for his truck rebuiild project.
Check out the NAISSO tech forum, It's a gold mine for this.
triumph5 wrote:
Curtis, thanks for the diagrams, they will come in handy.
I'll take my time, pay attention, and simply do it.
I just find it hard to believe GM would bury such a normal maintenance item in such an awkward, deep-recesses of the engine.
You're welcome.
GM buried it because its NOT a normal maintenance item. The "opti" stands for optical trigger (not "optimum" like most people think.) The optical trigger is an absolutely wonderful and accurate thing. Its brilliant. The secondary "spark" part seems like its no better than an old HEI but it is. Mine went 133k without issue until the rotor snapped, but even at 133k the contacts looked like an HEI cap with about 10k on it. High energy, close tolerances, gold plating, etc. Nice stuff.
I get a kick out of folks who go to great lengths to bypass the secondary side and use a Delteq coil-on-plug conversion thinking that they've spent a wise $1800. First of all, the Delteq uses the stock optical pickup which is just as susceptible to water damage since it hasn't moved, and secondly the Delteq system uses Northstar coils... quite possibly the least reliable coil setup known to man and hideously expensive to replace.
Think of it this way - your water pump will need to be replaced twice before you'll need to service the Opti, (or 7 times if you use Dexcool) so just plan your maintenance during a water pump swap.
The people hated the Opti because it was dying all the time, but the real culprit was the chronically leaking water pump right on top of it. Two things will make your life SO much easier - first, get an entire Optispark unit from a later vehicle. Its vented with a positive airflow provided by the intake. Any condensation or water that gets in there is almost instantly removed by the airflow of the intake ducting. Second, take a little plastic or brass vacuum nipple and epoxy it in the weep hole of the water pump. Then run some 1/4" vacuum hose down to the crossmember or something. Then the pump can leak all it wants.
The placement of the Opti also helped out with timing accuracy. Since its driven directly off the cam snout with a little coupler, it is less likely to exhibit the play and inaccuracy associated with driving a distributor off the back of the cam. Gear tolerances, wear and (believe it or not) twisting of the distributor shaft in a conventional distributor setup makes for very inaccurate spark compared to the Opti. Heck I had a billet Mallory HEI on a Sun tester that dropped a full 2 degrees at 6000 rpm from shaft twisting.
I've done it without messing with the crank pulley. Not fun but doable. Plugs and wires? Your hands WILL be shredded. I think GM bolted random razorblades in the engine bay just to cut you.
Thanks all for the advice, and insight. Owner wants to do this because there's a low throttle-application stumble, and this is on the list of things to do. And, with the mileage, it is/was(?) considered a normal maintenance item.
Gonna put in new plugs first!
Then go for a drive.
Of note, the car sat for a while, until bought as the beater/divorce replacement car. And it was not putting out heat at first. After some driving, a couple of days, no problem with the heat, and no problem now, either.
So, it's time for a sit down: "Is this really just a beater, or is it a multi-year replacement?" If so, new pump time...
Appreciate all the explanations, details, other sites, and possible manifold change. I think a reality check is in order, too.
HD gloves are on the list of stuff to buy this morning...
And the owner laughs at my Spitfire....open the "hood" sit on a tire, and go to work...
Again, I wonder what a dealer would charge for this 6-8 hours at $70/hr?
triumph5 wrote:
Again, I wonder what a dealer would charge for this 6-8 hours at $70/hr?
Urm, $420-$560, I'd reckon 
triumph5 wrote:
Curtis, thanks for the diagrams, they will come in handy.
I'll take my time, pay attention, and simply do it.
I just find it hard to believe GM would bury such a normal maintenance item in such an awkward, deep-recesses of the engine.
Thank goodness I never had to replace the spark plugs on this thing. It's hard to believe that taking this engine out of a massive Camaro and shoehorning it into a little British car or a Miata improves ease of servicing, but it does.
And here I thought you guys were just messing with him for being so stupid he couldn't even see the distributor.
I can't believe that's where they put it.
Toyman01 wrote:
Thank you Lord for for letting me buy a 93 Roadmaster with a normal distributor. I thought it was a PITA to change the cap and rotor on it until I saw the above.
those are easy, just cut down a nutdriver to fit under the windshield and you're good to go!
Ranger50 wrote:
Just get a 93 intake and some gaskets, drop a distributor into the hole, and eliminate the craziness.
that won't work. the LT1 intake doesn't have any coolant passages in it, and the heads have no coolant passages in them. the bolt pattern is different, and the ports are taller on the LT1 than on the older TBI motors.
there are people that have modified the LT1 intake to use a regular distributor, but that would be a definite step backwards.
honestly, it's not that hard to get to the distributor on an LT1- and it's not something that needs to be done very often. i parted out my 94 Caprice with 227,000 miles on it and it looked like the opti had never been touched- when i changed the water pump about 15,000 miles earlier, every bracket that i had to take off to get to it was rusty and didn't look like it had ever been touched. when i swapped my water pump, i think my car was out of commission for a little bit over an hour, and the opti is only a few bolts from coming out at that point.
routing the new plug wires in the stock looms is, however, a bit of a nightmare.. why the fine engineers at GM Powertrain decided that the Corvette exhaust manifolds (or similarly designed manifolds) weren't good enough for the Caprice is a mystery to me...
Bobzilla wrote:
Toyman01 wrote:
Thank you Lord for for letting me buy a 93 Roadmaster with a normal distributor. I thought it was a PITA to change the cap and rotor on it until I saw the above.
those are easy, just cut down a nutdriver to fit under the windshield and you're good to go!
i used a 1/4" swivel adapter to get to the cap on my 92 Caprice... easy... and when i tried to swap in a different distributor, i learned that they used a distributor with a bigger od where it goes thru the matching larger hole in the intake manifold to allow enough clearance for the distributor to come out from under the cowl..
