Hi Mike,... . about 1200 years ago I was into the two-way hobby myself... .
I could never figure out why the "man" was all bent outta shape just cause I could push near 850Watts from the old tube driven ham rig I had... . go figure. .
Just as a thought... if you have a magnetic mount antenna, try running that one and see if the noise issue is cleared up... it can be as simple as the location and/or grounding ... ...
Admittedly things have changed and improved since then but I found some common issues that cause or contributed to receiver noise... .
The biggest one was ground issues... . that includes the radio ground as well as other vehicle ground contacts.
On our trucks there is really very little "electronic activity" that a car would/might have.
If you look at the neg terminal on the battery, there is a small black wire that runs to the rad support. It isn't very long and is secured by a single self tapping screw..... not really that great...
Remove and clean that baby up, then, get some good 1ga or 2ga multistrand wire and run another ground from the neg terminal to the frame rail and/or the block as well.
Make sure the fastening points are nice and clean and use some dielectric grease. This will not only help the contact be as "positive" as possible but it will also help reduce the normal breakdown of the contact over time.
The area on/around the front of the engine by the vibration dampner is only accessed by the crank position sensor. It is a magnetic pickup. If you look over the grille/rad towards the front of the engine you'll see a wire (usually in a wire loom) heading down behind the clutch fan and pulleys... . this goes down to the small magnet mounted at about the 11:00 position just above the dampner itself.
The contact you'd want to check for that is on the front of the cylinder head just part way down front of the head. This is a simple two wire connection. Open that up, clean it out really well and use a tiny tab of dielectric grease on it and reconnect.
Next, you're going to look at the two wires that connect to the injection pumps' start/stop solenoid. That is a basic 12vdc ciruit. Those spade terminals also get real sloppy over time and are often the cause of intermittent engine shutdown headaches... . again, pull the terminals off, snug up the spade portion and clean off the terminals on the solenoid. Re-install using a bit of the grease. It doesn't matter which wire goes were on that one.
After that, you move down to the KSB solenoid. It is also a basic 'dc' circuit but it is only active when the weather is cold so it is unlikely to be your problem but your in there anyway so re&re like you did with the start/stop contacts.
From there go to the sensors on the intake manifold... repeat the electrical maintainence process as above.
If you still have noise that is constant and unvarrying then you may want to wrap a braided shield around the wiring we've discussed.
Years back and on one of my installs I put a multiband ham radio in my Ford PU... .
I found that I had to take some of the sheilding from a piece of the heavier coaxial cable... about 4-5" long, cut it lengthwise and wrap it around the underside of the antenna mount/connection, then, either solder it back to gether or use a series of tiewraps to pull it together to form a good solid connection/shield.
Well, that's all I can think of at the moment... . some of the other guy's will jump in here with some really good idea's instead of my "old as dirt" thoughts. .
pb... .
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