1994 LT1 caprice problems

[mattiscool28]

My 1994 caprice has a few problems. First the outside of both of the front tires are wearing down really fast! i replaced the tires less than a year ago and im going to have to change the two front ones again because the outside of them have gotten so bare. The second problem is my car has a little miss to it. It almost putters and the car shakes when you hit the accelerator. It only does it when ur not floring it. and i just changed the spark plugs and wires. Is their anything i can do to fix these problems?

[kahjdh]

the tires are an alignment problem, they are both pointing inward causing then to wear fast. The missing could be alot of thing but is prob timing. SLOWLY turn the distributor cap until it idles better.

Edit: do 94's have optispark? then i dunno

[ilgoldstein]

I don't think you can do that with an Optispark.

Any recent water pump/hose problems? If plugs/wires are ok, it may be the opti. I don't know if it would go away above idle, though. Also, fuel injectors, maybe. I had a Caddy with a bum injector, would chug at idle, but the engine was strong enough to run at normal speed without noticing a problem.

[mattiscool28]

Thanks for the advice, ya i was going to change the distributer cap, and i bought one that was about $180 dollars but after looking at the engin my dad and i both knew it was going to be a hard job. so we returned the part. It looks like we need to take off the water pump and a bunch of th ings to change it. Is their any easy way to get in their and replace it...? My tech. didnt even want to do it.

[Blue Bowtie]

That's odd... My '94 B-Car seems to wear out the REAR tires a lot faster than the front.

If you have that many years on it and have never changed the Opti cap and rotor, it MAY be time. It MAY be something else just as easily. Given your description, I would look elsewhere before digging straight into replacing the Opti cap and rotor. Weak spark or spark scatter tends to occur under load, not at idle. The higher compression pressures tend to create more resistance to the spark, and cause weak ignition components to route the spark somewhere other than the intended path. Since you mentioned that the problem seems to occur only under moderate load but not heavy load, it could just as easily be a fuel mixture problem. Still, it could also be the Opti. Or the ignition wires. Or weak/worn plugs. I'd check or change those items first, since they will be necessary even if the Opti is failing.

If you determine the Opti is the problem, there are a couple things to remember. The '94 B-cars used the vented Opti cap, unlike the F- and Y-cars. That's a good thing, since they last longer that way.

There is no "easy" button for replacing an Opti. It's not very difficult work, but it is time consuming.

1. You'll need to pay close attention to the orientation of the harmonic balancer when you remove it from the hub. Mark both parts clearly with paint so it goes on exactly the way you removed it;
2. You should also plan on at least replacing the rear seal in the water pump when you remove it, or replace the entire pump with a remanufactured unit. You'll really kick yourself if you have to do this twice because the water pump starts leaking in a few months (which could be the cause of the Opti failure in the first place);
3. You will need an external Torx socket to remove the cap and rotor from the Opti. I believe it uses an E-4, but I could be mistaken and it may be a tad smaller;
4. The optical sensing arrays (source/receiver) and interruptor discs need to be cleaned when you disassemble the Opti unit, otherwise you may be wasting your time. Isopropyl alcohol, a compressed air supply, and some cotton swabs are about all that's necessary;
5. Measure the resistance of all the ignition secondary wires, inspect the insulation along the entire length of each wire for damage.
6. Reassemble the plug wires and other connections at the Opti with silicone dielectric grease when you install them to both the distributor and plugs;
7. Inspect the water pump drive collar for wear when you remove it. If the spline is worn, it can allow wobble which will quickly cause the water pump seal and/or timing cover seal to leak;
8. Plan on using antiseize compound on the fasteners you reassemble;
9. You will need a torque wrench capable of at least 70 ft/lb for assemble;

Of course, if you do this, you'll need to get another Opti cap and rotor kit. You can shop around for a little better price than $180.00. Any of these will fit:

Niehoff DR80K $123.99
Standard Motor Products DR473 $144.44
Borg/Warner C400 $139.99

None of them are as cheap as the old style cap/rotor kits, but there's a lot more involved.

And you may also want to research the process a bit more. Do a web search for "Mike Chaney" and "Opti". He has a nice article on the rebuild here:

http://www.charm.net/~mchaney/optisprk/optisprk.htm

Your's will be very similar.

[Blue Bowtie]

If you determine the Opti is the problem, there are a couple things to remember. The '94 B-cars used the vented Opti cap, unlike the F- and Y-cars. That's a good thing, since they last longer that way.

There is no "easy" button for replacing an Opti. It's not very difficult work, but it is time consuming.

1. You'll need to pay close attention to the orientation of the harmonic balancer when you remove it from the hub. Mark both parts clearly with paint so it goes on exactly the way you removed it;
2. You should also plan on at least replacing the rear seal in the water pump when you remove it, or replace the entire pump with a remanufactured unit. You'll really kick yourself if you have to do this twice because the water pump starts leaking in a few months (which could be the cause of the Opti failure in the first place);
3. You will need an external Torx socket to remove the cap and rotor from the Opti. I believe it uses an E-4, but I could be mistaken and it may be a tad smaller;
4. The optical sensing arrays (source/receiver) and interruptor discs need to be cleaned when you disassemble the Opti unit, otherwise you may be wasting your time. Isopropyl alcohol, a compressed air supply, and some cotton swabs are about all that's necessary;
5. Measure the resistance of all the ignition secondary wires, inspect the insulation along the entire length of each wire for damage.
6. Reassemble the plug wires and other connections at the Opti with silicone dielectric grease when you install them to both the distributor and plugs;
7. Inspect the water pump drive collar for wear when you remove it. If the spline is worn, it can allow wobble which will quickly cause the water pump seal and/or timing cover seal to leak;
8. Plan on using antiseize compound on the fasteners you reassemble;
9. You will need a torque wrench capable of at least 70 ft/lb for assemble;

Of course, if you do this, you'll need to get another Opti cap and rotor kit. You can shop around for a little better price than $180.00. Any of these will fit:

Niehoff DR80K $123.99
Standard Motor Products DR473 $144.44
Borg/Warner C400 $139.99

None of them are as cheap as the old style cap/rotor kits, but there's a lot more involved.

And you may also want to research the process a bit more. Do a web search for "Mike Chaney" and "Opti". There is a nice article on the rebuild here:

Opti Repair

Your's will be very similar.

[NOVAZ27]

Replace the EGR valve. They get weak with age letting the engine surge at low speeds. My mother's 94 Caprice LS with the 4.3 V8 (baby LT1) had the same surging problem. A new EGR valve cured this problem right up.

HOPE THIS HELPS

[j cAT]

this post is 4 years old ....!