Tune Up for 1994 seville

[stogiedude]

So, the car is running real rough. It has 75,000 miles. I got it with 56,000 miles about two years ago. As far as I know it's never had wires and plugs replaced before I got it or the O2 sensor either. In addition to doing plugs and wires and the O2 sensor, anything else y'all recommend?

I haven't done any repairs myself in a long time so I was planning on buying the parts and hiring someone to do this for me. What should it cost for labor?

What plugs do you recommend for this motor?

 

[artificialist]

ACDelco plugs+wires.

Also, while you are down there, replace the distributor cap and rotor if your car uses one.

 

[Jimmy9190]

You are starting in the right direction with the tune-up. A new air filter, AC Delco plugs and wires or the Napa OE Belden equivalent wireset would do just as well and may be less expensive. Replace the distributor cap and rotor if your car has them. Again I recommend Napa OE grade (Echlin) or the Delco parts. I personally would not replace the O2 sensor unless the Check Engine Light is on and the PCM has stored a code for the O2 sensor. You might check the Idle Air Control Sensor if you have one, and the Mass Air Flow sensor and or Manifold Air Pressure sensor, whichever ones your car has. Napa should have those parts as well and at the age and mileage on your Caddy it might be good insurance to replace them. If you have an external fuel filter you might replace that as well. If possible, remove the throttle body and clean it thoroughly, then run the tank down to near empty and add a bottle of Regane or Techron Concentrated fuel system cleaner. Fill up and run that tank nearly empty, refill the tank without any cleaner in it then after running that tank out, repeat with a second dose of fuel system cleaner. Others here may recommend Seafoam in the gas tank and down the throttle body, or just about every dealership and garage in the Tampa area will have the BG fuel system cleaning procedure. BG is a good product and a good service but it can be expensive. Others may offer a similar service with the EverWear brand of cleaning products.

If these don't help the car run better you might pay a visit to Mr. Goodwrench to have the PCM scanned for fault codes. Autozone and others will check it for you too, but I think they only check the codes if the Check Engine light is on.

You might also pick up a Haynes or Chilton manual for your car. Reading and studying it and of course posting here on BITOG are very good ways to help ensure the dealer and/or mechanics don't take advantage of you. I believe there are a number of professional technicians and gurus with GM experience here who may have more info for you. Let us know how it turns out.

 

[stogiedude]

I was planning on using generic, universal wires. I really don't want to spend a lot of money on this car. It's old and if I can't get it running good I'm going to have to dump it as a "mechanic's special". At 75,000 miles I don't have a problem replacing the O2 sensor whether there is a code or not, it's only about $50 or so. Good idea on the air filter and I'm going to change the oil and filter too. Those sensors are probably expensive so they will be the last to be changed and only if they have a code indicating they are bad. I will definitely run a bottle of Regane through it as well. Not going to pay the big bucks for BG.

Anything else fellers?

 

[blackcherry06]

If this is a 94 Seville, it should have either the LD8 or L37 Northstar, which has direct ignition. Tune-up for this engine is normally limited to spark plugs and a fuel filter. If it's still running badly after that, 02 sensor or one of it's many other sensors are to blame.

 

[[RT] ProjUltraZ]

also check out the numerous Top end cleaning threads here. shoot out the throttle body with throttle body cleaner, MAF cleaner to clean the MAF, fuel inj cleaner in the gas, all these can cause rough running. then change plugs

my 94 has the opti and coil. once i noticed the coil wire was corroded going to the opti. it wasn't even running really rough but eveything improved after that

 

[stogiedude]

It's the Northstar engine. Until just recently it ran good and was a [censored] cat. Fast car and fun to drive. All of a sudden it running real rough. I went to advance Auto parts to day, it was on the way so I stopped in to check on plugs and wires. The parts guy said the engine would only run good on AC Delco plugs. I asked him if he knew of a good mechanic and he sent me across the street. I stopped in and asked and they said a plugs and wires tuneup would cost about $200 parts and labor. SOLD! The car goes in there tomorrow morning.

He said the best thing to do was to check all the engine codes if it's running so bad and then go from there, so that's what is going to happen. He said O2 sensors installed were about $100 a piece and I have two front O2 sensors, that sucks, but if it makes the car run good I'll pay the money.

 

[stogiedude]

Well, I finally took the car in to a mechanic and it was two coil modules? Two of the cylinders weren't firing and that's why the car was running rough. He said it didn't need plugs and wires. Cost me $115. That is one of the smallest mechanic bills I've ever had. I'm relieved that I don't need to replace some expensive sensors or an EGR valve, seems I got luck for once. Since I don't do any auto repairs anymore I'm at the mercy of the mechanic. I've gone through a lot of mechanics over the years.

I go pick up the car tomorrow morning. He's going to get a bunch of business from me. I have other cars with other problems...