Stumbling yet again

98 Mustang GT

I re-gap the plugs... stumbling goes 100% away for 3-4 days.. then comes back. I regap (1-2 are off??) and it's gone for another 3-4 days...... WTF? A never-ending cycle. Any ideas? Thanks. Oh..using Ford Motorcraft Platinum plugs.

-Mike

Reply to
<memset
Loading thread data ...

Sounds like a weak spark Mike.

Maybe a coil pak problem to me.

-ERIC

Reply to
Katmandu
** 98 Mustang GT ** ** I re-gap the plugs... stumbling goes 100% away for 3-4 days.. then comes ** back. I regap (1-2 are off??) and it's gone for another 3-4 days...... WTF? ** A never-ending cycle. Any ideas? Thanks. Oh..using Ford Motorcraft Platinum ** plugs.

How off are 1 & 2, and how are they off? Closed up? Opened up? Have you double-checked all of the secondary wiring to be sure that everything is well seated and nothing has been damaged?

What 'mods' have you done to the car in the last few weeks?

________________________________________________________ | | | 1998 Laser Red GT RAMFM Member Since 1998 | | M-5400-A Suspension http:/207.13.104.8/users/jdadams || Subframe Connectors & Seat Bracing, Strut Tower Brace || 4-point K-frame Brace, Tremec T-45 & OEM 3.27:1 Gears ||________________________________________________________|

Reply to
JD Adams

What do the removed plugs look like?

Grey - Blackish - Whitish?

John

Reply to
John Shepardson

Hmm.. maybe whitish... but not really.. they look similar as to how I bought 'em... new.. but whitish is the closest thing to it. What's that mean?

-Mike

Reply to
<memset

wrote in news:45cpc.260$ snipped-for-privacy@newssvr23.news.prodigy.com:

Ditch the plats and get copper - much better conductor. And make sure you gap them properly. 2 cents.

Joe Calypso Green '93 5.0 LX AOD hatch with a few goodies Black '03 Dakota 5.9 R/T CC

Reply to
Joe

kk.. will try copper next time. Thanks Joe =).

-Mike

Reply to
<memset

Based on what you told us and the fact that you are under the hood leads me to think that its not the plugs but the coil or the wires. You have not given us a lot to work with so I'll make a hypothetical supposition. Without mods it sounds like you may need new spark cables. Ford runs hi energy ignition systems and the wires tend to wear out after a year or 2. Check your cables for cracks or grounding. Take your horse into a dark area and see if your cables are touching by looking for spark along the cables. Also look for flash or spark around the coil.If you see anything then there's your answer.

Reply to
The Inquisotor

Only are are CAI & Steeda tri-ax shifter... suspension coming up very soon. As far as I know.. the plug wires have *never* been replaced... and are starting to look a bit worn. The ignition coil packs look like they're in good condition still, but I mean how much can you tell just by appearance... so.. I'd hafta lean more towards wires. I'll look into it more when I return from my trip. If it is the wires, should I replace w/ OEM wires or go with a different brand like MSD? I'm not looking for performance from the wires, just reliability. OEM worked great...

-Mike

Reply to
<memset

No problem - just a thought. BTW, the Inquisitor had a good suggestion - if the wires are OEM, try replacing them. OEM is certainly good, but if you go aftermarket don't get anything with less conductivity than OEM. Some brands look great with the colors and all, but might not work as well as OEM.

Joe Calypso Green '93 5.0 LX AOD hatch with a few goodies Black '03 Dakota 5.9 R/T CC

wrote in news:BAipc.339$r_7.309 @newssvr23.news.prodigy.com:

Oh..using

Reply to
Joe

You're looking for a nice light tan colour...... Have you checked your MAF sensor.... I use a magnifier to look for a "fur coat" on the upwind side of the 'hot' wire. (I assume there are no codes and the a KOER was done???).....

If the MAF has any deposits, BraKleen works well..... if there is a need to 'help' the cleaner, you can use a "babies first toothbrush" kinda thing VERY, VERY gently. Allow plenty of time for it to air dry before reassembly.

You have seen that there is no permanent fix in the spark plugs..... if, for some reason you suspect them, replace them - other than that move on to find the problem rather than pounding your head against the wall 3 times a week.

I can't recall, is this a COP system or does it have wires? Is everything seated correctly. Is the motor washed regularly? What is the weather like? Look for identifiable patterns in operating cicrcumstance. What modifications? Where are the fuel trims when the problem is occuring? Am I getting EGR flow when I shouldn't?... these are all questions I would be asking myself given the same circumstance.

If the problem persists, you may need to do some real searching to fond a dealer that cares with a good driveability tech

Jim Warman snipped-for-privacy@telusplanet.net

Reply to
Jim Warman

Could someone please explain to me how a bad coil or wires would change the plug gap? On some GM cars the "platinum" on the plugs is just a tiny round ball imbedded in the center electrode and the ground strap. They fall off. That changes the plug gap.

Al

Reply to
Big Al

I'd hafta lean more towards wires. I'll look into it more when I return

If you have determined that it is a firing problem, then I would replace the plug wires with Ford OEM wires. MSD or Accel will not give you any better performance and may impede, same for the coil. As I mentioned Ford uses a hi energy ignition in all Mustangs.

Reply to
The Inquisotor

Big Al, I don't think the gaps changed, I think he went back in and checked then re-gapped again.

Reply to
The Inquisotor

Al.... I'm working on an explanation of ignition secondary now........ hopefully I can get it so that there's not too much in the way of confusion - look for it sometime tomorrow. Some basic understanding of electrical behaviour will help....

Reply to
Jim Warman

It's not the spark, unless it's the spark advance; it's the fuel mixture or the timing.

A weak spark will still ignite a proper fuel mix at the right time.

Check timing, first. If it's okay, move on to fuel.

The air-to-fuel mix should be around 14:1; you're probably getting less, which means too much fuel to too little air.

Check your fuel injectors.

Check your air filter and air flow detectors.

Check your computer.

You have an imbalance in air and fuel; not in spark.

doc

Reply to
doc

I popped the hood & realized 2 of the wires were NOT fully seated on the driver-side ignition coil pack.. but were only barely off.. I dunno if that could be part of the problem or not...

No, the motor isn't washed regularly & in its current state... is fairly dirty (i knooowwwwwww...). I recently replaced the MAF meter.

Is there any way to check the plug wires? They've got a little over 100k on 'em... I imagine it couldn't do too much damage to replace 'em... I'll keep looking though. No codes are showing up... I'll debug some more tomorrow. F*cking cars are so hard to diagnose... major props to good mechanics.

-Mike

Reply to
<memset

I"m actually a little afraid to use anything other than OEM w/ the plug wires...

-Mike

Reply to
<memset

Well when I regap plugs it runs fine for 3-4 days... usually starts running rough after I drive it hard for a while. Also... I didn't adjust timing.. I can't w/out a timing adjuster (ie: Steeda timing adjuster) or a chip as far as I know... and I have neither. I tried Lucas fuel injector cleaner.. problem still exists. Air filter is clean & MAF & IAT sensors are new. I also reset the computer... and no codes were found. I really think spark is the problem, not air/fuel... but I don't know squat so I could be wrong.

-Mike

Reply to
<memset

Oh and again.. I really do appreciate everybody who's replied on this thread... all of your ideas & advice/help is VERY much appreciated.. thank you all again. I'll do some more diag'ing tomorrow. G'night.

-Mike

Reply to
<memset

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.