my engine is sputtering sometimes at idle. The service engine light soon light comes on and off all the time, and it doesn't have a smoothe shift at high RPM's. It will hang out in the 6K rpm range for a while, or it will do a small shift before shifting into the next gear. What is wrong with my car? Thanks!
Jason

 

When the SES light flashes while you're driving, it means the engine is misfiring. Usually you'll find that you have a burned plug wire or something like that causing it. Check your plugs and wires, this is the most common cause that I've seen. Not sure if this is your problem since you didn't post much info, but maybe it'll help.

 

Well i got new plugs and wires a little while ago. I did find out before when the engine light came on that an ignition coil was shot, so i bought a new one and replaced one of the 3 coils. So maby another coil has gone bad? Do you usually replace all 3 of the coils? This is probably the probem, what do you think?

 

That's definitely possible and probable; especially since you've had problems with coils before. I've never had a coil go out so I'm not sure if you're supposed to replace them all at once but I don't think you have to. When I had a problem like you're describing, it was because of a burned plug wire; and I had the Taylor 8mm wires and NGK plugs too. Some were too close to the exhaust manifold.

Anyway, even after I replaced the wire I still had a problem and I tried new coils, ignition control module, fuel filter, etc and none of that fixed it. I took it to the dealership and they "rerouted" my wires and it fixed it! I have NO idea what was wrong. I had them hooked up right, 100% sure, but I guess they weren't "lying correctly" in the engine bay? It is still a mystery to me.

Sorry that was so long. If you know a store you are cool with (I am cool with O'Reilly near my house), you can buy new coils and just test them out; if it doesn't fix it, take them back for a refund. That's what I did with my coils and ignition module (over a hundred dollars) and they took it back since they were cool. If this is possible for you to do, it would be a great chance to try for free and see if coils are your problem.

 

Well napa said if i buy the ignition coil they wouldent let me return it. Also I noticed today that when i get up to speed fast it doesn't just pause before switching gears but it goes from a 3000 rev up to like 5000 rev in no time, then at the 6000 shift point it will hang out there and go from like 6000 to 6200 rpm's for a while and doesn't shift untill i let up on the gas a bit. I think my car is a junker, but is this a minor problem that can be fixed?

 

You'll hate me for saying this, but it could be SO many things. Here is my advice: do a search on this site of the LT1Tech forum with the keyword "sputtering". There are many threads there that I saw and you'll see what I mean about how common this problem is and how it could be like 30 different things causing it.

When you have mechanical problems, I advise searching LT1Tech because these problems exist with both the V6s and V8s. You will find MUCH more help and advice in LT1Tech searches.

It might be the cheapest and most painless choice to just take it to a dealership and have them figure it out. Some people in LT1Tech have spent tons of money without solving the problem.

I STILL have a hesitation problem with my car and I'm trying to figure out what it is; it only does it at WOT for me. It's not the same as yours. Double check your wires. Make sure none are burned. If you have a timing light, you can check your wires with it most likely, and see if you're getting equal spark on each one. I found one of mine slower than the others when I had a prob similar to yours. Do whatever free checks you can like that. If nothing seems out of the ordinary, you might have to take it in to avoid a wild goose chase trying to figure out what it is.

Anyway, search in LT1Tech and see if you can find a post that resembles your problem the most and see what they say about it. I wish you good luck.

 

One more thing i did was take each spark plug off at the coils, and the new coil bought sparked rapidly, and all the other old plugs on the coils were mediocre, by far not as rapid as the new coil, the problem before was that one of the plugs wasn't giving off any sparks and the new coil fixed the problem. So would you suggest buying all new coils? Even if I can't return them to napa? Thanks for your suggestions.

Jason

 

I would think it's a good chance that you have some failing coils if you aren't getting as rapid a spark on those old ones as you are on the newest one. If you're sure no wires are burned and no plugs are bad, I would try some new coils. I'd hate for you to waste $ on something that may not work but it sounds like it might be it.

 

I hate my car. I bought new coils, so there all new and i didn't see any difference, it's worse if anything. It now sputters, mumbles, or whatever it sounds like when it's idleing in park. I want to shoot it. I pour all this money into it and it can't work. What do I do? If I bring it to a shop it will cost 2-300 just to see whats wrong with it. The only difference I could see was they sparked really fast, while the other ones weren't as fast or as on beat. Another difference would be the shifting it shifts better than it did before. The real problem is that stupid "service engine soon" light it stresses me out constantly, is there a way to shut it off? If the light goes away I will be happy.

 

First of all, sorry about what happened I know the feeling though.

So there was no change in the coils and they are still going unevenly? The SES light is going because your car is misfiring badly. I don't know if you can shut it off but all it does is tell you it's misfiring (as if you didn't know that already).

Your ignition control module could be bad.. it's that plate that the coils plug into. It's a $150 part. I really would take it to a dealership (where they will be more likely to know about V6 bird problems) or a mechanic you like.

Get in touch with some other f-body people in your area; they might have a computer they can hook up to your car and check things out for free (shops charge ~$80 for this). Friends of mine have gotten lots of help this way. It could be your cheapest choice.

 

Well i did notice that the new coils gave off lots of fast sparks, where the old ones didn't have fast and even timed sparks. So I think that may have helped the shifting be more sharp. But when it idles it mumbles and grumbes a little bit sometimes. Someone said that when the "SES" light is on solid it has to do with your emissions controll and when it is flashing it has to do with your ignition/spark plugs. So they thought I might need new o2 sensors or my catalac converter cleaned out. Does this sound right? Could the o2 sensors need replacement? And where are they located and can you tell my looking at them if they need to be replaced? Thanks for your help.

Jason

 

Ok I'm glad the coils gave you a little improvement at least!

Oh SES is on solid? Sorry I assumed it was flashing. It could mean many many things if it's on solid. You have to get the code our with a scanner to find out what it means for sure in your case.

About the o2 sensors, that's also very possible. I think that might be the problem with my car too.. I have that common problem where I get hesitation/uneven acceleration when I mash the pedal down, and it gets worse as the engine warms up.

Where they're located.. I'm looking at my Haynes manual (you should get one) and it says they're in the exhaust manifold. Argh, sorry I'm not much help here; I've never replaced any or even looked for them before.

 

Well I doubt it's my transmission, I had a new one put in about a year ago. I got new spark plugs/wires a month and a half ago, so those metal boots are gone. The SES Light was flashing for a while, a while ago, and I replaced one ignition coil and it fixed the problem. Now it's a solid light, i replaced the other two coils and it didn't do much except give me more sparks. Right now I taped a piece of paper over my SES light so it doesn't bother me. I'm sure it will but atleast I don't have to look at it all the time.

The light did shut off for about 20 miles today, but it turned back on when I was going 55 mph for about a half minuite. It usually turnes on when i get on the highway and set my speed. 55-65mph. Do you think my engine is misfiring? Or could it be my cold air induction? I put that one a year ago, and havent replaced or cleaned the filter. It says it can go for 30K miles without replacing or washing. It's been about 15K. I can't figure out how to get at those filters either thats why I havent cleaned them.

I also am worried it might be the fuel pump. A few times when the engine light shut off was when I got a tank of gas. But maby that's a coincidence? Thanks for your help!

Jason

 

Since you have so much experience with these types of problems, what is the most common cause of a hesitation during "quick" (I use that term relatively) acceleration with a 3.8L? This only happens once the engine has reached operating temperature, or the car is running in closed loop, whatever you want to call it. It hesitates really rough like it's couging and about to die. Total disaster but it only happens when I attempt to stomp on the pedal a bit. I'm thinking o2 sensors but people think nah. I have had a misfiring problem before and I drove it like that for 5 days, about 30 miles a day; don't know if that's enough time to damage it(them). I was told it isn't enough to damage them but I'm open to more opinions. Thanks in advance.

 

Getting on the throttle (as the engine gets hotter, it becomes easier to induce) it will hesitate in a surging manner. It will pull forward some then like it's starving it will just quit going... then a burst of acceleration for a split second, then it has nothing again.. and it just does acceleration like that if it's very hot or if I am trying to do some moderately quick acceleration.

It feels like a misfire surge thing except without the misfire, popping, and backfiring. It does none of that. It just can't go smooth and it's quite jarring. It's either some sensor or something or my transmission can't grab. I dunno.