97' EightyEight - Sputter/Hesitant @ 40-45mph - Then Engine Light Solid

Okay, First of all this place rocks. I have had excellent help with my previous and first post here (http://www.automotiveforums.com/vbulletin/showthread.php?t=409718) . I thank you all again. :smile:

New issues with my car have recently developed. After my problem with the intake plenum was resolved as mentioned in the link above.. the vehicle ran just how it did before, super. The spark plugs were changed, fluids, and of course the intake plenum. Just FYI to some of the people out there... a failing intake plenum can cause some weird ass problems for some, and I was one of those unlucky fools... anyway..

~~~

Scenario::eek7:

I had just relocated to a new area and the speed limit around town is between 40 - 45mph. So I am constantly cruising around at those speeds. Two days ago I felt the car kind of make the same sputter that it did just before the intake plenum failed (see above link). Once I pass the 40 - 45mph mark the sputter stops. That first day it idle'd fine and would only sputter when reaching those speeds. Yesterday it got worse. I started the car for the first time of the day and the engine light was now on - solid. It was now also doing the same sputtering feeling I had felt driving the day prior, except now it was doing it while in park. I took a small drive around town and once gas was given the sputter would stop when coming out of idle.. once it hits about 40mph it starts being hesitant again and then stops once I get over 45mph. I did search around the best I could before making this post on issues similar or related to mine but I have a hard time coming to a conclusion since I am a bit of a hypochondriac when it comes to my car. Tomorrow I will hopefully make it to an autozone or something just so I can have them run the codes. I just wanted to ask here first since I had so much results last time with my previous problem. Also, I like at least being able to suggest things to the mechanic(s) I might speak with regarding the issues since I do not know very much about automobile repairs. However, I am getting better (or tend to think) and this forum is the reason.

~Thank You

Specs:

97 - Olds - EightyEight
98,888 miles
3800 - Series II - V6

Related Posts other than my own:
1 (http://www.automotiveforums.com/vbulletin/showthread.php?t=434592)

A half dozen things could cause what you describe from various ignition problems to a worn out TCC or warped flexplate.


We need the codes.

Okay, I am sorry for the late update but had to take care of a few things. I finally had the codes read and the results detected a misfire which I pretty much assumed. I decided to take it to another garage with a more advanced computer that pinpointed the coils. So I replaced the coils and its running much better now. However just a few days after replacing the coils it still seems to still misfire at about 2100rpm' around the 55-60mph area. The spark plugs are new and were replaced about 4,000 miles ago. Now I am curious if the faulty coils messed up the sparkplugs causing the newer but subtle sputter. I am probably going to take the car back to the garage. Will keep ya'll posted A.S.A.P.

Did you replace the spark plug wires. That may be the reason the coils failed in the first place. Just because the look good doesn't mean anything. You can change them yourself and see what happens. I doubt the plugs have any problems since they are relatively new. The wires are probably the culprit!

Did you replace the spark plug wires. That may be the reason the coils failed in the first place. Just because the look good doesn't mean anything. You can change them yourself and see what happens. I doubt the plugs have any problems since they are relatively new. The wires are probably the culprit!

Yes GTP Dad, you are correct sir! After even having the coils replaced there was still an ever so slight miss. However the new coils did take care of the very noticeable miss. I replaced the plug wires myself and all is just peachy. In addition but slightly unrelated issue.. and I can not stress this enough ..new battery cables on this car or any car that may need them is a great idea. So go ahead and replace those while your replacing your spark plug wires. :p

the sputter at 45-65mph.. i would say it could be the OverDrive. but i dont know about the back fire and stuff