'96 LC ticking issues..... (1 Viewer)

[Bumpin' Yota]

First let me introduce myself, Im a professional installer from sarasota with a 90 4runner. If you frequent Yotatech you know who I am....lol Anyhoo I have a problem I want to share and gather info on, and believe you me I have SEARCHED all over the place...

I didnt do the install in question but one of my coworkers did and managed to get himself in WAY over his head and me a little bit too...

Apparently Customer purchased 96 Land Cruiser and noticed a ticking noise that was RPM dependant in the FM radio. As the RPMs went up the speed of the ticking increased. Turn engine off and there's no ticking. Apparently ticking wasn't there with AM or CD operation. Coworker installs speakers using factory wires, and installs deck (pio dehp6800mp) using your standard met 70-8112 toyota amplifier integration harness.

Well tick is still there, and the customer wants it gone.

The first thing I checked was to make sure it was the speakers and not a valve or injector and it indeed was eminating from the speakers... Then we tried ground loop isolators, regrounding the deck to the chassis, regrounding the deck to the negative post of the battery, cleaning both battery terminals, checking ALL grounds in the engine bay, grounding the case of the factory amp, grounding the case of the deck, and tried different grounding points in the engine bay. We also tried a new deck, an amplified VW antenna adapter, and nothing fixes it!!

This leaves me thinking 2 things - spark plug/spark plug wire is bad, or even the distributor or rotor... Either that stuff or the factory amp needs to be bypassed. Thoughts?

 

[firetruck41]

I would be suspecet of the spark plug wires, but really am not an audiophile, I just know that original wires, at that age can cause stumbles, loss of power etc. Stands to reason they are "leaking" and causing other electrical problems.

Also, you are in the wrong section. Try posting in the 80 series section

 

[Bumpin' Yota]

whoops didnt know i was in the wrong section! LOL Hey mods if you could be kind enough to move this thread to the 80 section it would be awsome!

Incidentally I believe I found the solution courtesy of a friend over on yotatech linking a thread here...

https://forum.ih8mud.com/showthread.php?t=38577&highlight=radio+noise

 

[GeoRoss]

Is the ticking worse on the low end of the FM dial?

Is the ticking RPM dependent?

Is the tone of the ticking steady or does the pitch increase with RPM?

Since you report that it is on the FM side I would check for arcing at the distributor and check the dist cap connections as one might not be fully on. This assumes that the wires are in good working condition and in spec.

Ross

 

[Bumpin' Yota]

Is the ticking worse on the low end of the FM dial?

Not really. You can still hear the ticking on the low end of the FM dial as well as the high end. Oddly enough you could hear it much better on 104.5, an old rock station around here, more than on the empty channels such as 88.3. However ticking can be heard in every frequency if you listen closely enough.

Is the ticking RPM dependent?

Yes! Engine must be on and it is RPM dependant. If RPM increases the speed of the ticking speeds up. The interval is not fast enough to be the coil or the coil wire going to the distributor, but it would be about right for one of the cylinders every time it fired....

Is the tone of the ticking steady or does the pitch increase with RPM?

The tone of the ticking remains 100% steady, and dang near sounds like my 3.slow's injectors...lol Only the ticking in the LC is definately through the speakers.

Since you report that it is on the FM side I would check for arcing at the distributor and check the dist cap connections as one might not be fully on. This assumes that the wires are in good working condition and in spec.

Ross

cool! Looking at the wires they looked kind of old, but no worse appearances than the wires on my 3.slow. Ill call the customer tomorrow when Im back at work and let them know.

Question: Why would arcing at the distributor and the interferance it generates only come in on FM and not AM?

 

[GeoRoss]

cool! Looking at the wires they looked kind of old, but no worse appearances than the wires on my 3.slow. Ill call the customer tomorrow when Im back at work and let them know.

Question: Why would arcing at the distributor and the interferance it generates only come in on FM and not AM?

Arcing produces some sort of RF noise that comes in on FM, that is about as technical a answer as I can give. That the tone doesn't change as in RF noise through the altenator makes me think it is with the distributor.

I had the same noise in my 80 when I bought it. I was doing a full tune up, new wires, plugs, rotor and cap. The noise went away. I didn't drive the truck for about 2 months (my wife did) and when I got back it was making the noise again. Searched and searched and found a thread with a similar issue. I pulled all the wires from the dist. cap and put them all back on. I have been click free for 6 months.

Good luck.

Ross