I bought this car last month being told that the chugging problems was due to dirty fuel injectors.
So I changed them, did not help on bit
Then I found this site and registered, so I can find out some answers...
I checked out the EGR valve, it was clean and centre spring mechanism worked...
Then I changed the Idler valve and throttle position sensor. Seemed to work, so I took a short 3 hr trip to my brothers, it acted up with in 30 minutes, then shortly after that, ran fine, so that I was able to use cruise control again.
On way back though, it chugged all the way, in fact I was stuck with rush hour from Toronto to Hamilton and the car was pure HELL to drive, almost stalled quite a few times.
Today I changed the igniton modules complete.... did not do a thing.
Well now that I gone this far into it, and had no success, is there any suggestions available... right now I'm getting a 0300 on my scanner with the SES on, of course that's the 3rd cylinder misfire, but wires are correct and new, all I can ask is "HELP"
Oh, it's standard with 225,000 km on it, and single cam.

Chuck

 

Well, changed the water temp sensor, cleared the SES and then took car for a 30km ride.
The SES did not come back on, but she still bucks under acceleration, or hills.
I'm guessing its the CAT, but when I put my anylizer on it, the #1 o2 sensor changes constantly, and the #2 sensor is somewhat steady at around .7, sometimes it would drop down to .1 and then come back to .7
This tells me that the CAT is ok, according other posts I've read on this matter.
I'm at a loss right now for an answer, I'm now guessing fuel filter, so I'll do that tomorrow, but for the sake of arguement, she does buck and has lack of power for heavier acceleration.... I'm still leaning toward the CAT...

Chuck

 

It sure sounds like a fuel related problem to me, Chuck. Change the fuel filter first and run some Techron fuel system cleaner through a tankful of gas. Lack of power on hills and under acceleration could be a clogged or restricted cat con or muffler. A lot of times if a cat con is clogged, you can look under the car and that sum beech will be glowing! That's with the car running at at operating temp. As far as the plugs go, what brand did you stick in there? If you got Bosch from Autozone, that may be your problem. Look under the hood or in your owners manual and see what is recommended and go get some of those. These damn cars are very picky about aftermarket products. Sensors and such things need to be GM OEM stuff.

 

0300 is a random misfire code not cyl 3 misfire.
When you replaced the ignition system, did that include the DIS module under the coil packs too? I'm thinking the answer is yes but want to be sure we are on the same page.

What kind of plugs are you using? S cars usually do not play well with anything that is not plain old style copper plugs. Stock NGKs are greatly preferred for these engines.

Good to see that you replaced the ECTS. Was my next suggestion anyway.

Hard to understand the "sometimes ok, sometimes not" scenario as it relates to the cat; I would be skeptical of a partial clog forming and dissipating but then again I don't work on cars professionally.

The behavior of the 02 sensors sounds about right -- and the reading on the rear o2 sounds good, so I will lean away from the cat being the issue but you can't rule anything out.

IF the fuel filter doesn't help--

1) You might want to do a loan a tool from autozone and get a fuel pressure gauge and make sure the pressure is with in spec while driving--you can usually snake the hose between the windshield and the hood, then latch the hood on the first click but not fully closed. Then go for a spin and see what the fuel pressure is doing during chugging and bucking. May be a bad regulator or weak fuel pump.

DRIVE SAFELY

2) Don't forget that the front 02 sensor sends feedback to the PCM to constantly adjust the air fuel mix to get a 0.7 reading on the rear 02 after the cat con. While the numbers may be bouncing around like you'd expect, they may be bogus due to the sensor being worn out (100K miles is about the lifetime of the front one).

If not a fuel system problem per 1) above I'm thinking your bogging may be due to the air fuel mix being hosed.

My suggestion is to consider replacing the front 02 sensor. Replace it with a DENSO brand sensor. DENSO is OEM and from personal experience, my two s cars run worse with a brand new bosch sensor than they did with the worn out factory ones.

 

Yes Derf... I changed the module with the coil paks.
as for the plugs and wires...
Plugs I put in are BOSCH plat4
Wires R-7 SAEJ2031 premium

I still haven't got around to get a fuel filter, I've been quite busy and just use my ol 98 sl2 ... it's still rocken and it's over 300,000km now.

So You think maybe the plugs might be the bad chugg'n ???

CHuck

Just a thought....
Maybe if I take the plugs out of my 98 along with the wires, check it out that way, maybe even the fuel filter???
After all, it is running good... ummmm, might be something to do later today, being the temp is up over the Zero

 

yes swap in those plugs and wires, but only make one change at a time (all the plugs alone or all the wires alone). Otherwise you're changing two things at once and then you don't know which caused the problem.

I'm betting on the plugs for the random misfire

 

Hallaluya ... got it, it was the wires... my new ride is now running like a champ. I have never had this type of problem before, it is definately a learning curve.

Thanks

Chuck

 

Glad the mystery is solved and you are up and running.
saturns like OEM parts under the hood.
Now we know another brand of aftermarket wires not to buy (lol).
I'd still recommend getting those platinum plugs out in favor of the stock NGKs or something copper)

Hope you kept a hold of the DIS/coil packs you pulled -- you likely have a spare set if you did