Missing. --If not plugs or wires.... then what?

[morebhp]

Okay guys. New question. Same problem. (bare with me here... )

This weekend I cleared my KAM. Left battery disconnected for 2 days. This morning I drove to work in 22 degrees. (Michigan ) and guess what... missing... skipping. I'm not sure if the cold emphasizes it or not. I know the cold increases resistance in electrics so I suppose it could make them more prone to short.

Now, I know what you are thinking; "Replace your plugs and wires Einstein!!" Well...I would... but they are only about 2 years old... with maybe 10K miles on them. They are all OEM and very carefully installed. I REALLY doubt it's the pugs or wires. So what if I go get new ones to the tune of $150 and it doesn't help.

So, my question to the panel: Assuming (and we agree it's <U>my</U> assumption) that the plugs and wires <U>aren't</U> the culprits... what would you say next? Coil packs? I'm at a loss to think of what other items are subject to the ignition amperage and therefor the shorting.

Is this something that can easily be tested with common equipment?


Thanks!

 

[sdpatt]

Is the CHECK ENGINE light illuminating? If so, check the codes for your answer. If not, then the source of the misfire is either the plugs or wires. The EEC has no means to know that there is a malfunction in this portion of the ignition system. All other components upsteam of the plug wires can and usually will set an error code upon their malfunction. There could be moisture in the plug wells or even an arc track condition down the side of one plug's insulator. These two conditions do not care about the age of the parts.

 

[Mr Anonymous]

Codes? Always best to start with reading the codes. If there aren't any, that usually indicates a plug or wire problem. You should also double-check all ground connections, esp. the ground path from the DIS to the firewall via the intake.

What brand plugs and wires are currently installed?

What's a KAM?

 

[Whitefish]

Had a similar problem with my 94. Twas the plug well seals.

Hope that's it.

Lonnie
94 MTX Stock

 

[projectSHO89]

morebhp:
I know the cold increases resistance in electrics so I suppose it could make them more prone to short.

Not really. Only a device with a NTC (Negative Temperature Coefficient) would behave that way.

For the most part, it is the other way. Resistance INCREASES with raised temperatures and DECREASES with lowered temperatures.

Steve "I have an electronics degree somewhere on this desk" W

 

[morebhp]

Is the CHECK ENGINE light illuminating?

No, Never comes on.
--------------------------------

There could be moisture in the plug wells or even an arc track condition down the side of one plug's insulator. These two conditions do not care about the age of the parts.

Okay, that makes sense but how do I avoid it happening again? Do I have to replace the plugs and wires every 6 months?
---------------------------------

Is the CHECK ENGINE light illuminating? If so, check the codes for your answer.

What brand plugs and wires are currently installed?

What's a KAM?

No codes.
Plugs and wires are 100% OEM. KAM is keep alive memory. I've been developing a mixture problem over time. Clearing KAM gets rid of it.. for a while. --It may be a short causing the HEGOS to lean out the mixture. (just a theory)
--------------------------------

Had a similar problem with my 94. Twas the plug well seals. Hope that's it.

I just checked again. There's no oil in the wells. If its shorting... its somewhere else... or caused by something else.

--So then if I understand correctly... you all are telling me that if I had a problem with my coil pack... I'd definitely be seeing a code. Is this correct?

<small>[ November 10, 2003, 12:27 PM: Message edited by: morebhp ]</small>

 

[sdpatt]

Yes, the EEC can detect circuit problems in the primary coils of the coil pack.

You mentioned a mixture problem. How and why do you think this? There must be codes generated by at least an oxygen sensor(s) indicating that the mixture is less than optimal. Please tell us the whole story.

 

[morebhp]

You mentioned a mixture problem. How and why do you think this? There must be codes generated by at least an oxygen sensor(s) indicating that the mixture is less than optimal. Please tell us the whole story.

Well Scott, if I knew the whole story I'd be glad to tell you... but then I wouldn't need to post questions here. As I said in my last reply, I have no codes. But.... if I drive the car for 6 weeks without resetting the KAM (keep alive memory) the mid-range power slowy degrades. If I then reset the KAM, the power loss disappears. I've done it scores of times. No codes, no replaced parts.

I don't understand it. It's frustrating and annoying. But it's reality. If that's the way SHO's work... then I was lucky enough to have two other SHO's that did exhibit this characteristic.

Believe what you want, and assume what you want. I've been chasing this problem for a few years now. (as time and money allows). I've checked for codes many times. Of course that was my first thought too. There just aren't any there.

In the trial & error process, I've replaced MAF, TPS, plugs and wires. All of which did nothing. Before I rebuild the engine one part at a time, I'm just asking to see if anoyne else had this happen to them, and if and how they resolved the problem.

Thanks

<small>[ November 10, 2003, 02:55 PM: Message edited by: morebhp ]</small>

 

[Anthony1238]

Possible Fuel Injectors... Take a long screwdriver and place the flat end on the electrical connector of the fuel injector.. put your ear to the other end and listen for a ticking sound coming from it... if no ticking is present you have a clogged or failed injector... I used a mechanics stethascope to diagnose the problem.... I had almost the same problem, possible from a bad fuel filter.

 

[sdpatt]

By "no codes" do you mean that you are finding "111" for both the hard faults and the memory codes when executing the KOEO test?

 

[morebhp]

Right. With the exception of the occasional "536" or "522". I get "111". shrug

Let's assume I do indeed have an arc occuring again from a plug or plug wire. --Should I look for a cause? I know for 100% sure I don't have oily plug wells. So, could it be something else? Anyone ever had "chronic arching"? --Even with relatively new plugs and wires? I don't get my engine wet. Its not particularly moist here in Michigan. I just don't get it. Grrr! I'm not really hip on spending $120 again for new freaking wires.

 

[qiksho]

If it was my car I would pull each plug and inspect it, check the gap. If nothing else It might give u more insight on ur mixture problem. I would then re-install putting a little dieelectric grease (sp?) on the insides of the plug boots to keep out moisture and reinstall everything.

I would also check to make sure you don't have any cuts or nicks in the wires. I have seen new wires where they were cracked where the wire comes out of the boot.