Engine wiring loom?

[pwpanas]

Originally Posted by redsupra

OK, so to answer my own question.

I took the car to a local auto electrician who tested the coils and found the front two were harldy suppling any signal. Being 18 years old I guess it was time they expired. So I got a new set of Super Spark coils and connectors shipped in and fitted. The sparky said the wiring was perfectly ok, (says little about what a mechanic knows about this stuff, and he wasn't complimentary about mechanics either when talking about their knowledge of auto electrics).

So the existing loom was re-wired to the new coils and the car is running perfectly well now. I'm a happy camper

With that last major "under the hood" issue dealt with I can now plan on some new rims, complete re-spray and new sound system.

1) The Mkiv's coils can't be properly tested, except under load
2) I'm pretty sure that Toyota still sells the plastic coil connectors. The oem plastic gets hard, brittle and cracked. Let me know if you need the part number.
3) Did you replace all of the coils? If not, they all usually begin to 'wear out' within a few thousand miles of the others, so you'll likely need to replace the others eventually if you haven't already. However, you should get at least 125,000 miles out of a set of coilpacks.
4) For whatever it's worth, your symptom and the fix don't really go together. Weak coilpacks fail to ignite the air/fuel mixture under hard boost. They don't cause "higher than normal revs at idle when the engine is warm". If you ask me to guess, I'd say your so-called mechanic fixed a vacuum leak he didn't mention to you, while selling you coils you probably didn't need. *shrug*
5) I'm pretty sure that Toyota would still sell you an entire primary wiring loom. Warning - it's quite expensive $850USD+. Not sure why you're concerned about replacing the 'pig tail' ends. *shrug*
6) You should never solder a harness/loom. A proper 6-sided crimp with shrink-wrap is the only thing that should be used on any wiring in a moving vehicle.
7) Those plastic connectors go bad because of heat. Anything you can do to reduce under-hood heat will help them last. For example, have you considered a vented hood?

Either way, congrats on the fix. Glad it worked out for you.