1998 Chevrolet Lumina Engine Stottering

[MAD King]

Hello,

My engine starts stottering sometimes at 35 mph, then sometimes at 45 or 55. Engine light is not on. Spark Plugs have been changed one week ago. It also needs a little bit more on gasoline.
What can this be?

Thank you

[maxwedge]

I assume stottering? means misfire? If so did it do this before the plugs, a bad wire or coil can also cause this.

[MAD King]

Thank you for oyur response.

That is not a misfire I think, because the engine light would come on, right?
But your advice with the coil is good. I will change it together with the distributor cap and rotor.

[lumina_98]

I'm researching a misfire code on my car presently. I'm not a mechanic so anything I say take it as guestimation. Did you change the plugs yourself? My wires were very hard to remove so you could or someone else could have damaged a wire. Gap correct? But a misfire should turn on the check engine light. I'm wondering if bad gas could cause 'stottering' and not throw a code? You said the car "needs a little bit more on gasoline"? Are you saying the fuel gauge is on empty? Fill it up but not from the Pack A Sack that might be cutting it with water. Air filter clean? I think low fuel pressure and plugged fuel filters yield random misfires which would also turn on the light. Why don't you take the car to a parts store that reads codes for free? I think Autozone will scan it. Are there engine codes that exist but do not turn on the light? I don't know but the pros here would know.

[maxwedge]

You need to look at how your ign system is designed, there is no cap and rotor , you have direction ign., 3 coils, wires and an electronic control,module., research this or get help before you get into this.

[MAD King]

Originally Posted by lumina_98

.....I'm wondering if bad gas could cause 'stottering' and not throw a code?

Weird that you wrote this. I filled it up yesterday with BP gasoline and the stottering is gone. Can it really be the gasoline or is it just a coincidence?
There is no error code when checking it.

[MAD King]

Originally Posted by maxwedge

You need to look at how your ign system is designed, there is no cap and rotor , you have direction ign., 3 coils, wires and an electronic control,module., research this or get help before you get into this.

I just found it out. Do you think I should replace it?

[jamesmetairie]

if the shuttering is gone with the new gas don,t worry about it.
depending how many miles you have every car will need things like plugs ,etc. when the time comes. good luck .

[MAD King]

Originally Posted by jamesmetairie

if the shuttering is gone with the new gas don,t worry about it.
depending how many miles you have every car will need things like plugs ,etc. when the time comes. good luck .

Do you think I should just ignore what it might be caused?
I am wondering why it disappeared with the gasoline from BP.
My Lumina got 170000 mls on it and almost everything was replaced recently except the coil.

[lumina_98]

This car with the stottering (great word I'm adding it to my vocabulary. It's like stuttering combined with tottering and overall running terrible) is used regularly correct? Gas in a sitting unused car goes stale. If regular use you could have picked up some bad gas. If it's running smooth and no codes forget it until something real crops up.

[MAD King]

Originally Posted by lumina_98

This car with the stottering (great word I'm adding it to my vocabulary. It's like stuttering combined with tottering and overall running terrible) is used regularly correct? Gas in a sitting unused car goes stale. If regular use you could have picked up some bad gas. If it's running smooth and no codes forget it until something real crops up.

UPS. Sorry, that I misspelled stuttering. lol
In German it is written stotter and thats maybe why I wrote stottering.

I always fuelled my car with cheap gasoline and last time I could not find a gasstation except the BP. I will go only to BP gasstations in the future and pay a few cents more.

[kevinb70]

Mad King, were you the one who mentioned Hess Mart as to where you got your gas? Avoid them. Who knows, you might be getting 15%-20% ethanol in there. Plus water, from poorly maintained equipment.

< Techron junkie

[MAD King]

Originally Posted by kevinb70

Mad King, were you the one who mentioned Hess Mart as to where you got your gas? Avoid them. Who knows, you might be getting 15%-20% ethanol in there. Plus water, from poorly maintained equipment.

< Techron junkie

Yes, but I didn't know that they had 15%-20% ethanol in. I will stick with BP, Chevron and Shell in the future and pay a few bucks more on a tank.

[MAD King]

Today came the engine light on and it gives me the error P1870.
After googleing a bit I found some websites mentioned that this is a common problem on the transmission valve body. I remember now when this problem started. It started after I replaced the tranny fluid and filter, but I don't understand why.
Do you guys think that can cause the stutter ?
I also wasnt able to find any valve body part and how to replace it.

Thank you

[lumina_98]

Factory manual has some words on P1870.

Power control module monitors the torque converter clutch slip by calculating the difference between the engine speed and the transmission output shaft speed. When the power control module detects excessive amount of slip when the torque converter clutch is engaged the P1870 is set.

You mention tranny fluid and filter elsewhere. Is the fluid level correct?

Not a mechanic so just reading and writing but a slipping torque converter doesn't seem to describe your earlier stottering.