93 ciera 3.3 sluggish/hesitant

[nharstad]

my 93 old ciera has become very hesitant/sluggish. 3.3L 215,000miles automatic. When backing out of our garage after just starting it is hesitantes until we get on the road and give it some gas. The check engine light also comes on when we are on the highway. The code comes up Oxygen sensor so i replaced it, nothing has changed. I have noticed that when on the highway if the light comes on and i accelerate hard for 5 seconds or so the light goes out for a while then comes back on.

I have replaced the spark plugs with platinums, and put new wires on.

any ideas

[flyguy123]

I have replaced the spark plugs with platinums, and put new wires on.

any ideas[/quote]


Platinums are known to fowl easily, I would just throw OEM plugs in it. Did you reset the computer after changing the 02 sensor? Is it running rich? What kind of spark are you getting?

[maxwedge]

Welcome to AF. Scan it again, get the exact code and post back.

[nharstad]

I will make sure the computer is reset, and take the car out tomorrow and check the code. So we know for sure what is going on.

[nharstad]

ok I disconnected the battery for a few minutes, and checked to make sure the codes had cleared, then took the car for a drive, the result was

trouble code 44 - Oxygen sensor sensor voltage was under 0.25 volts for 4 1/2 minutes of closed loop operation.

I replaced the oxygen sensor just a couple of weeks ago when I started trying to figure this out. So from what I have read there is some problem with the fuel system. But on that note about 1 year ago I replaced the fuel pump and filter.

And of course this car is not a normal fuel injection system from the time frame because it has no egr system, and no distributor.

I know after I replaced the fuel pump the car never got quite the same fuel milage it got before, but I had also replaced the spark plugs with a different kind at the same time. Later I bought and put in the spark plugs I previously had and the milage came back up, but maybe not completly where it was to start with, cant remember for sure maybe just 1 or 2 miles less per gallon.

Any ideas.

Thanks

[nharstad]

Well I have replaced the Fuel Filter and the Throttle Posistion Sensor, and checked the fuel pressure. They are all good.

Any ideas?

Does anyone know anything about the Mass Air Flow Sensor?

[maxwedge]

Same hesitation? Any more codes?

[nharstad]

i have replaced the spark plugs also now

same sluggishness and same code

it still hesitates when you start moving then once you get moving it is fine until I get on the interstate and then five minutes later the chec kengine light comes on with that same code

[maxwedge]

The engine is running lean, many things can cause this, air entering unmetered, into the intake, look for any vacuum leaks or leaks in the ducting to the throttle body, dirty injectors, low fuel pressure are the most common.

[nharstad]

I have checked and cannot find any bad vaccume lines, I have tested the fuel pressure and it is fine, and have also run a bottle or two injector cleaner through the system.

The only thing I dont know how to test is the air entering the intake. The Mass Air Flow Sensor is suppose to do that but I cannot find any way to test it. And it costs over $150 to replace it, so if I dont have to I dont want to spend that money.

My friend has a scanner I am going to try to borrow that can check the systems while the car is running, but I need to know what voltages and such I should be looking for.

[nharstad]

Well I never got to use my friends scanner as he is having car problems himself.

But the other day i noticed; we had a snow storm and I backed the car out of the garage and through a small drift, and noticed green snow had come off from under the car. I got out and looked and it was coming off of the catalyic converter, but only when i drove through snow, otherwise it never dripped.

Now our car isnt using and noticable amount of coolant, and that is the only green liquid I know of. So I am guessing that either a head is cracked or the intake manifold gasket is going bad.

Does anyone have any other thoughts, or know how to figure out which one is failing?

[maxwedge]

How about a basic pressure test to start out with, see if the cooling system hold 16 psi. BTW, do you loose coolant, again basics.

[JohnDD]

My 91 Olds Cutlass Ciera had an O2 sensor code come on when the exhaust manifold/ gasket were defective. I could smell the exhaust fumes a bit when I started the car. After the repair, they had to reset the service light a second time (forgot the first time)? but car ran great afterward and no more exhaust smells. I finally buried the car after 383,000Km.
Good luck.

[nharstad]

ok i have a update

I have replaced the o2 sensor, tps, iac valce, pcv valve, plugs, wires, ecm, cannot find any vacume leaks.

I have noticed that the car runs just fine in neutral or park, but only hesitates badly when in gear. The car idels somthly and revs just fine until you put it into gear.

Does that give anyone new ideas?

Thanks to anyone with some advice

[Slade901]

Your catalytic converter might be partially clogged which gives you a hesitation problem. The only way you will know for sure is to use a back pressure gauge. You basically remove the O2 sensor and then screw in the back pressure gauge there and see if there is a very pressure reading indicating plugged catalytic converter.

I have replaced catalytic converter before myself by just cutting the ends of the catalytic converter with a sawzall. Don't use hack saw, it will take forever. Get replacement catalytic converter by itself and use a clamps and pipe connectors from autoparts store. That is what I did on one of our older vehicles. If you buy a whole catalytic converter and it's long pipes, it's very expensive.

Or

Call around welding businesses and call them which one will install a replacement cat for you. They will cut out the old cat itself and put the new cat in there and weld it. I paid $75 for them cut and put the cat on one of my vehicle.