[StinkhornPress]

1993 300E auto. 150,000miles owned for a year and half, no major work done to it under our care (regular oil changes, brake pads, tires, HVAC fan replacement).
Haven't gotten around to flushing fliuds - know it needs done. Haven't done basic replacement stuff, wires, plugs etc.
Where's the best place to start chipping away at neglected service and hopefully address the miss at idle at the same time?

 

[LeftCoastGeek]

check the spark plugs. odds are pretty good you'll need new coils, wires, AND plugs.

 

[sbaert]

^This AND being a 1993 make sure that eco junk has been adressed.

If not, all bets are off.

And 2nd, your car has a disposable ignition system that needs to be replaced (3 coils, 3 plug wires, 3 coil to plug boots and 6 plugs) every 100-125K miles with plugs every 25K miles.

And lastly, the ONLY suitable plug is Bosch F8DC4. No exceptions.

 

[StinkhornPress]

^This AND being a 1993 make sure that eco junk has been adressed.

top harness replaced/addressed before we purchased.
the "starter harness"(??) is still bio junk, I haven't figured out exactly what harness/term I need to keep a search out for...

 

[Jayare]

Search for "lower" harness. Last I checked, they were NLA. However, they are stone simple to rebuild. There are threads galore on this.

Jayare

Sent from my XT1080 using Tapatalk

 

[StinkhornPress]

wires are my nemesis. i suck at solder. hell, i suck at crimping.
i looked into this once, got confused, threw my hands up and walked away. PRETTY sure, nothing is actually shorting out, not causing the issues, but clearly needs addressed at some point soon.

 

[sbaert]

Start by overhauling the entire ignition system.

 

[plinker17722]

Slight miss ,, i would go for bad plug lead or HT lead . Look at all the ht leads make sure they are all screwed in to the connectors. My lead was loos on one .I replaced it thinking that the fault was inside the leead ,.I opened it up and thats what i found If the leads are good then check your coil out ..I dont know of you have the m104 or m103 ..You could just get one long ht lead and swap it out .Untill you find the bad one . My info is for the m103 .

 

[LeftCoastGeek]

He's got a 1993, which is the 3.2L M104 HFM engine, with coil-over-plugs

 

[plinker17722]

Bit of a hit or miss ,,if poster never lets us know what engine they have the problem with .. Nothing in the profile .Like so many ..

 

[LeftCoastGeek]

Bit of a hit or miss ,,if poster never lets us know what engine they have the problem with .. Nothing in the profile .Like so many ..

first post says "1993 300E auto." thats a 3.2L M104 HFM-SFI