Hey everyone, I have been looking for answers to my questions and I believe I have finally found the place!

I own a 1994 Camaro 3.4L V6 and I love this car! However I have started to experience some problems that I can't seem to find the solutions to. I bought the car in December and just recently started to loose power and performance from my engine. The engine only has 109k miles and I do not have any knowledge of prior maintenance performed on the car. I am new to car maintenance and repairs, but I have been working with a friend who frequently works on cars and owns a couple classic muscle cars. I have also been reading through the Hayne's repair manual for the car and have been learning as much as I can.

I have about a thirty minute drive to work, she ran fine all the way down to work. After my shift when I went to leave I noticed a sever loss in power and performance. The acceleration is sluggish and while running the car just feels "heavy". The idle is fine, it is not heavy, high, or too low. It is when I accelerate and keep a consistent speed. The things I have changed recently have been my air filer, fuel filter, oil and oil filter, and am in the process of changing my spark plugs. I bought ACDelco Platinum Rapidfire plugs as my replacements.

What else can I do to restore my engine's power? I have tried STP's Fuel Injector cleaner and STP's High Octane Fuel additive. These helped a little but I haven't really noticed a major improvement.

I couldn't stand to see this car go, nor do I have the money for a new car. I want the mechanical experience as well and have enjoyed working on this car, but I am starting to get worried that a major overhaul is needed.

Any help and opinions are greatly, greatly appreciated!
Thank you for your time!

 

No check engine light in the dash?

Loosing some power to a major overhaul is a huge jump. There are a lot of common issues that can cause a drop in power, Computer will see most of them and set the check engine lite.

 

Welcome to the forum! We do our best here to help you get your car back and running good. IF the CEL is on get the codes read and let us know what they are. Being an OBD1 vehicle some things that will cause a loss of power will not be noticed like on an OBDII vehicle. Sudden loss of power with out a CEL can be as simple as the fuel fliter is clogged to a PITA job like the fuel pump. Something else that is a good cause that will not trip your computer is the Catylitic Converter. OBDI did not have an after CAT sensor to determine the health of the CAT so if it goes bad you will lose power but not get a CEL.

For a fuel injection cleaner that really works and works good I use the Lucas Fuel System Treatment, that you can get at most major auto part stores. I get the big bottle that runs around $12 for the simple reason of cost to ammount. The $5.99 bottle is one treatment (same exact stuff) and it 5oz. The big bottle is 32oz for the cost of 10oz in the small bottle. Oh you may want to buy at least one small bottle tho... to use as a measuring bottle. Just use the large one to refill the small and get the right ammount every time.

If you are suspecting clogged injectors then use 5 or 6oz of the Lucas stuff each tank you fill up. I did this with a car that would not idle when cold and by the time I was done with the bottle (about 6 or 7 tankfulls) the car had no hard cold starting issues and no more cold idle issues. I love that stuff!! Now that my fuel systems are operating good I use 6 oz every time I change my oil.

Massey

 

Sounds like the cat is clogged or no good.

 

Thank you for your help guys!
I'm puzzled because there is NO check engine light displayed on my dash. I just finished the spark plug job and oil change this evening and it seemed to help a little but I'm still noticing a sluggish acceleration. There is also no Cat, it's just a straight exhaust pipe. Could it be something to do with my intake valve or plenum gasket? Or possibly a dead cylinder? I have yet to run a compression test, that was one of the next things on my to do list.

Is it okay to run the fuel injector cleaning agent on every fill up? I've been tossing in the smaller bottles about every other fill up and I fill the tank nearly all the way full.

 

Reality check, it could any one of many things or a combination or 2 or more things. What you’re going to get here is people saying “hey that happened to me and it was this”. Problem is there are just so many things that can cause low power there is no way anyone can tell you what is wrong with your car. In my head the biggest issue is the fact you just got the car. The previous owner may have done something to hide the issue just to sell it and that can make it MUCH harder to track down.

Does your service engine soon light work like it should? Does it come on with when the key is turned on without the motor running. Pulling bulbs and clipping wires is a quick way to make the SES light go off .

If the guy ran the car on low fuel pressure the O2’s should have complained because the system was running lean but if he ran it that way for a long time it would cause the O2 sensor to read wrong and if you cleared the code it may not come back.

I think the 3.4 uses speed density system (no MAF sensor) which means the timing and fuel is controlled primarily by MAP sensor, Air Temp sensor and Throttle position sensor. An issue with any of those Could cause a lack of power and may not set a SES light. Even a crack vacuum line to the map sensor could cause low power condition.

If you have a cylinder issue you would have a miss, these V6’s have a very noticeable shake when they have a cylinder not firing. Valve timing would be about the only mechanical thing that could cause a low power Issue, this would be a stretched time chain issue but I would not even check for that until I was sure everything else was working.

Do NOT throw away your old plugs, to a mechanic old plug are like a history book of how the motor is running. Keep them and hopefully you know which cylinder they came out of.

If it was my car, I would start with a fuel pressure test, then hook up a scanner and watch is the primary sensor seems to be working right and make sure the car is going into closed loop. Since I had no idea how old the O2 sensors where I would replace them. Then I could check to see if the new sensors report an issue.

 

Yes I do get a SES light when I turn the key without starting the engine. I don't believe that the previous owner had any malicious intent to hind anything before selling the car, or snipping the wires that would relay that message to my dash. I know her personally and her 90 year old father used to drive this car.

I will definitely check the O2 sensors and no I did not throw away my old plugs, I know better than to do that.

 

Is there a preferred manufacture of 02 sensors that have a high quality among Camaro owners? I was looking at picking up Boch's Premium sensors. After reading some customer reviews they seem to be the most well liked. Especially being a relatively cheap repair, it wouldn't hurt to replace the old ones anyway.

 

If you know them can you ask them about the issue? if it ever happened before? If they changed the O2 sensor? The equipment used to 'Check" an O2 sensor is very expensive many shops can not do it. The process to check an O2 sensor would cost more then replacing it.

 

I talked to her today and she said that no major repairs were done to the car while it was in her, or her father's, ownership. The most she said that was done to the car was new brake lines.

I don't think it would be a bad idea to replace the 02 sensors anyway. If they are bad, then replacing them just solves another problem. If not, at least I know I have new sensors in and can rule that out as an issue.

I really appreciate all of your help guys!