Problems after "tune-up," pls help a rookie

[ianwells100]

hi guys, ok, i bought my 95 3.4L 5 speed camaro in december 2002, and it ran pretty well. in february 2003, it was starting to backfire, and run a bit rough, i could have tuned it up myself, but with school and all, i was too busy, so i took it to a local mechanic, and he said the spark plug wires were really bad, and thats what was causing the main problems. after $300 CDN i took my car back, and was sooo happy, but i soon realized that when idleing, the whole engine just seems to feel rougher (it keeps at constant idle), the stick moves a lot more in idle, and the whole car slightly shatkes (in a certain pattern, if you know what i mean).
Above this, though, when i first start the car, and when i give it a normal amount of gas in 3rd or 4th gears, the car is very stuttery, and hesitates (no backfires, that i can hear), but this disappears after a couple of minutes. i use regular gas, and my car is totally stock (i just put in a flowmaster today) and have new spark plugs and wires, is this a problem with the distributer or coil??? i gretaly appreciate any help

[hockeyman]

Does your car throw a "sevice engine soon" light when it hesitates? If you replaced the plugs and wires, recheck the spark plug wire connections to make sure they are tight. Getting under the current f-body and reaching the spark plugs and wires at the engine block is a task in it's own (BIG Pain in the ***). So maybe there is a loose connection somewhere.
If the car is throwing a SES code, have it scanned! Troubleshooting our sophisticated cars on your own without scanning it will definately bring your bank account statements to an all time low, as the problem just seems to get worse.

-Marc

[ianwells100]

i took it straight back to the mechanic, and he did a computer scan, and said that nothing came up, and that i should try a better grade fuel for a while (done, makes no difference), or get the computer flashed by GM, or clean the fuel system...

the service engine light has come on for about 30 seconds one night, in the last month since this has started, soi don't think thats a problem, so i don't know what the problem is

[kahouna23]

Try the simple things first. Instead of taking it to a mechanic and paying him to tell you it doesn't throw any codes. Change the fuel filter, check the radiator and make sure you dont' have any "sludge" build-up. Change the oil and filter. Just the basic maintenance you can do in a driveway. The stuttering sounds like possibly the fuel filter. Probably hasn't been changed in a WHILE...I'm guessing. When you take it off, be sure to dump all the remaining gas out of it and get yourself a small dixie cup and try to blow through it. Careful not to splash anything in your eyes. If it's hard to blow through...I'd say that's the problem. You'll most definately get a bunch of black crap out of it. If that's not the problem, I'd say you have some sort of ignition problem. Possibly the mechanic routed the wires incorrectly and it's slowly burning through. Like I said before...start small and work your way to bigger things. Being a student you probably don't have $300 to spend every week on your car.

[Christian]

Sounds like the MAF, that's what mine was, basically the same symptoms. Might want to look at that man.

[lando_pr]

I don't think 3.4s have MAFs(mine doesn't). Could be the coils. They can cause a really bad case of missfire without throwing any code.

[Blackbird3800]

hey , my car does this too and i tried all the pour in the tank stuff and good gas and i got under the car and all the wires look fine and also i replaced all plugs and coils about 6 months ago , but however i did remove my MAF screen for a week but when it started this i put it back in and its been like a week and it still does this but never a ses light....any ideas??

[Christian]

No, I mean the sensor, the Mass Airflow Sensor, I thought 3.4's had them also, but I can be wrong, I have a 3.8. It had the back firing symptoms and all, plus I went with a tune and all, thought about it being octane pblms but all in all it was the sensor that needed to be replaced. Hope that's not the case for you pimpin', it set me bak about 4 big ones. Good luck on that though [img]graemlins/thumbsup.gif[/img]

[Backfire]

3.4L do not have a MAF sensor.

[genz11]

First off - take out your air filter and put in either a K&N or clean your stock filter (can get filter at local auto zone) .. secondly next fill up (87 octane) add a bottle of fuel injector cleaner to the gas tank and run it for about 15 mins on the highway. check spark plug wires.. check fluids - check guages make sure oil is changed or within the 3,000 miles. some backfire is normal for older cars i wouldnt worry too much (mine does it on a downshift) or high RPM to rapid low RPM i have 94 3.4... these are all cheap ways to gain some better performance in your car.. see if that helps.. if not its most likely a more serious (more expensive) problem..

[keith paterniti]

Just a point, make sure the spark plugs are in the correct firing order on the coil

[cb1101]

if it was a fuel filter being clogged, would'nt you be feeling the shaking all the time instead of just spurts?

I had a problem with backfiring and it was right after i changed my plugs. No more then 3 weeks later, my #3 wire was fried.