misfiring after plug replacement

[93 Grand Prix]

I am so damn tired of this motherf :cuss: After replacing the sparkplugs, wires, ox. sensor, my car still misfires worse than ever. It hesitates and stutters like crazy. What is it now :!: I also have a problem wtih my car in 4th gear, it has no accelleration :!: When it upshifts to fourth gear, I can't push down on the pedal without it starting to stutter. Could both of these problems be connected :?: I am about to give up on this car and go to the first-time buyer and get a Kia Sephia! Please help me stay away from this choice, at least until I graduate College (God be willing) :!: :!: :!:

[MaD]

Have you tried an Idle Relearn?

-MaD-

[GnatGoSplat]

Coil(s) or injector?

Do you have a timing light or multimeter?

[JPaganel]

Did you get the wires right? I've seen dealer mechanics mess it up and return the car that way. It never occurred to them they could do something that ridiculous...

[TGPilot]

I agree with JPagenal...retrace your wires especially if it is worst then before! I have made that mistake more than once and it frustrated the hell out of me. Also make sure the plug wires are seated properly on the coil contacts!... 8)

[cutlassdude96]

or better yet you could end up with a Kia Rio

[per0781]

kia = killed in action

 

think about it.

 

Paul

[93 Grand Prix]

Coil(s) or injector?

Do you have a timing light or multimeter?

Yes I have a multimeter, But I don't know how to use it.

[88Intl]

Before pulling plug wires, get a little tube of tune-up grease from the auto parts store. Apply a thin layer to the inside of plug wire boots. This helps boots slide on easy so you can feel the conductors snap into place, also seals out moisture.

 

First time I replaced spark plugs, was on my '73 Cutlass Supreme 350 motor. It ran much worse. Took it to the mechanic. He told me the gap was squeezed closed on one or more plugs! WTF??? No idea how that happened but if there's any doubt as to gapping pull plugs when engine is COLD and recheck. Before reinstalling plugs, apply a thin coat of anti-seize compound to threads. I like to use a torque wrench and torque to service manual spec, too loose can allow exhaust gases to blow-by and too tight can trash the threads.

 

Check that wires are routed away from sharp and hot objects. If you can get a GM shop manual, it may show the original wire routing. Anyone know of a username/password for service.gm.com ? I checked it out a long time ago, from a document URL posted somewhere, and was able to navigate the site and download manuals. No idea what the URL was. Maybe there are universal logons for non-employee users like auto repair school students.

 

Found this doc and saved to disk before it vanishes:

 

 

Idle Re-Learn Procedure

from http://www.sts.sae.org/membersonly/techinfo/articles/article7.htm

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In the article titled “2.8 and 3.1 Liter Chevrolet V6sâ€Â, the Idle Re-Learn Procedure was mentioned. If you are unfamiliar with this procedure, the following may assist you in learning this procedure. For additional information, please refer to Chevrolet bulletin #91-114-6E.

When B+ is disconnected on 1987 and newer 2.8, 3.1, and 3.4 engines, the ECM loses track of the IAC value position and the engine will usually not idle properly. The IAC position must be re-learned.

 

*Put chocks in front of front tires

*With key off, disconnect battery for at least 30 seconds.

*Reconnect battery. Do not touch throttle (ECM looks for 0% throttle openings).

*Start the engine and shift to “D.†Run for ten minutes or until cooling fan cycles.

*Shut off engine. Wait 30 seconds.

*Restart. Run 5 minutes in “D†or until cooling fan cycles.

*Check idle speed. (Note: the ECM can only learn eight IAC counts per key cycle).

*Repeat procedure if not correct.

*Remember that when the throttle opening is less than 2% ( 2.8 ) or 5% (3.1), fuel delivery is based on IAC counts. Correct IAC position is critical to prevent stalling. Normal is about 15 counts.

 

 

[RedZMonte]

does it miss under load only or does it miss in neutral as well? do you get a check engine light?

 

RedZ

[93 Grand Prix]

It doe not show a check engine light.