Hi All,

Today the engine started rough idling when on neutral.

I saw the voltage indicator drop at times from 14V to something like 8V.

I am normally running on regular gasoline but this time got good deal on Super so may this be issue, that I would doubt actually.

I would appreciate everybody's input as I still would like this baby running for a while.

Thanks,

Larry

Could your alternator be taking a dump on you? If it goes away at higher speeds, it might be the alternator.

_________________
2012 Chevrolet Cruze Eco - Current car

1999 Buick LeSabre Custom - Former car

Learn from the mistakes of others, that way when you mess up you can do so in new and interesting ways.

Or the alternator is dropping due to the lower rpm's of the rough idle. The alternator may not be the cause, but an after-effect of the real problem.

Check your plugs and wires first. Vacuum leaks also.

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Click here for mod list for both cars
93 SSEi, 95 SLE (supercharged) 97 Buick LeSabre Limited
PontiacDad at WCBF '04: Cruise control? That's like surrendering!
Comprehensive guide to troubleshooting, rebuilding, and modifying Eaton Superchargers

A lot of auto part stores will do an alternator/battery check for free.
If the alt/battery check OK then I'd look for vacuum leaks. When was the last time the plugs & wires were changed?

_________________
2006 Chevy Monte Carlo SS

Last time Sparks and wires were changes just 20 000km ago. They are good.

By the way right before the rough idle start, it rained a lot.

So it did rough idle and it stopped a few days after it is dry again.

I have moved the battery connections.

Also removed MAF sensor connection and saw that it started rough idling much different than before.

Funny when it did rough idle, no check engine was on, and no codes were given.

When MAF was disconnected, check engine came right on.

I have reconnected MAF and after few new start-ups, check engine is gone. All is ok now.

BTW one of my spark wires from the front was touching oil dipstick metal, guide, I have made the wire so t does not touch that metal part, also made sure other spark wires touch nothing metal, and so far all is well.

I have some more rain on the forecast, but much less than before, so lets see how it will play out.

Thank you for your quick suggestions and responses,

Larry

Rough idle is back.

Not sure where to start.

could it be bad, worn or clogged injector?

It feels though as 1 cylinder is chopping on low revs a little.

Ideas? Any fast cures?

Many thanks.

Larry

Remove the IAC and clean the passage inside the TB where it seats. Clean the bullet tip of the IAC valve. Do NOT turn the ignition on while the IAC is removed. Make sure the throttle plate is fully closing, and isn't blocked by carbon buildup.

_________________

Click here for mod list for both cars
93 SSEi, 95 SLE (supercharged) 97 Buick LeSabre Limited
PontiacDad at WCBF '04: Cruise control? That's like surrendering!
Comprehensive guide to troubleshooting, rebuilding, and modifying Eaton Superchargers

Thanks Willwren, what IAC stands for, please remind me.

However I think this might be just the case, as today as I have started it took me some leg force to press teh excellarator as it got stuck.

I is intake, A is air, what is C?

Are there any posts with pictures describing how to do this cleaning procedure.

What cleaner is best to use, gasoline or intake cleaner?

Or you just talk about simple clean up, that takes like 5 minutes?

Thanks,

Larry

ok, took a few extra minutes googled IAC valve and: IAC= idle air control valve is to keep the engine's idle smooth.

Sorry.

However, could this be linked with sticking throttle pedal? It gets hard to press as just started.

Larry

Your throttle body may need to be removed for a good cleaning. It sounds like your throttle plate is sticking. If it doesn't fully close, you won't get a good idle. When you remove the TB, you will lose a small amount of coolant.

Remove the MAF sensor from the TB and clean it seperately and GENTLY with a Qtip and rubbing alcohol (or MAF cleaner).
Remove the IAC, clean the 'bullet' nose, and then clean the back side of the TB of all carbon, paying particular attention to the IAC passage/seat. Use sensor safe INTAKE cleaner, not carb cleaner.

Lightly lubricate (light oil, WD-40 is NOT oil, it's a water displacing solvent that evaporates quickly), and reassemble.

_________________

Click here for mod list for both cars
93 SSEi, 95 SLE (supercharged) 97 Buick LeSabre Limited
PontiacDad at WCBF '04: Cruise control? That's like surrendering!
Comprehensive guide to troubleshooting, rebuilding, and modifying Eaton Superchargers

Thanks Willvren,

I did nothing yet, and the rough idle is gone.

I do not want to sound lazy, but I have cleaned TB some 3 years ago, actually I did not notice any improvement.

What could cause such rough idle/jigger when idling only, or when stopped and the gear on drive?

Could there be electrical problem.

Though I had no codes, no check engine lights came on.

When you say back of Throttle body, you mean inside the TB to clean as much as I can reach?

And I felt kind of that I think the wire that pulls the plates of TB is dry, can I put some oil in it, can it help?

Also as you say to lubricate after cleaning, so should I lubricate all TB inside or you just mean IAC valve?

Sorry for tons of Qs but I am detailed and since I am getting ready to do this I want to do this right, once and for long.

Thanks,

Larry

Update,

As Willwren has advised I have cleaned the TB and IAC.

All was fine and just today when I was on highway accelerating from 60miles to 80miles I felt as if the engine was loosing it`s ignition, or gas supply or whatever else that made it have a very short moment of jigger that kind of translated into dying, or shutting of, but since there was the speed it kind of was ok after I climbed passed 80miles.

Then just before parking, as 30 to 35 mikes, I just pressed accelerator more, and felt same jigging problem, and it felt as if there was too much gas in the mixture and the engine wanted to shut up, overflow with gas, or whatever else.

Or it also may have felt like there was water in the gas, that I doubt. But sensation was similar to that.

So it felt as you over-press the accelerator and it makes the engine numb, then it starts vibrating and him a little.

Would appreciate your input. Thanks.

Larry

PS how to make a post active or inactive?

With some correction on typos, sorry:

Update,

As Willwren has advised I have cleaned the TB and IAC.

All was fine and just today when I was on highway accelerating from 60miles to 80miles I felt as if the engine was loosing it`s ignition, or gas supply or whatever else that made it have a very short moment of jigger that kind of translated into dying, or shutting of, but since there was the speed it kind of was ok, and after I climbed passed 80miles there was no similar problems.

Then just before parking, as 30 to 35 miles, I just pressed accelerator more, and felt same jigging problem, and it felt as if there was too much gas in the mixture and the engine wanted to shut up/overflow with gas, or whatever else.

I opened the hood and tried to smell, but could not smell any gas.

Or it also may have felt like there was water in the gas, that I doubt. But sensation was similar to that, but very short.

So it felt as you over-press the accelerator and it makes the engine numb for that second for the moment, then it starts vibrating and hum a little.

Would appreciate your input. Thanks.

Larry

PS how to make a post active or inactive?

Here are some developments.

I have removed one of the wires at the park on the back (the longest wire).

As engine is on, and i go to the exhaust I can clearly hear and if I put my palm against the exhaust, I can feel specific puffing, and not even, showing that one cylinder is not working fine.

I suspect bad wire, or maybe I somehow connected it wrong, I will see in few hours and will tackle that wire.

What wires would you suggest to use and are there some good deals on Rockauto.

By the way on the way home the Check engine was "BLINKING" or "FLASHING" does that ring a bell?

As car is stopped and engine on, working roughly the check engine BLINKING is off. Also as I drive on highway without acceleration on 60MPH the BLINKING check engine goes off. And BLINKING may come back as soon as I force my accelerator tiny tiny bit.

Please brainstorm with me asap, so maybe after 2 hours when engine is cold I can tackle it and done.

Larry

PS Recently this car gave me and continues to give quite some fun, I mean work, I wonder who will prevail. LOL.

Update.

So funny, one spark plug wire at spark plug connection was unhooked.

I am not sure how can this happen, but can they just jump off like that?

And why there is that metal housing with the spring that the wire end must be inserted prior to connection t on spark plug behind the engine?

Larry