Starter coil replacement?

[Matt B]

As I had my first DNS occurrence last week - potentially caused by a heat soak after I changed my steering fluid - I intend to check the starter, add the groove to the backing plate (as described here http://www.zr1.net/forum/showthread.php?t=10321&page=3) and also check/replace the solenoid coil.
I did a lot of research but could not find any clear indication which coil to use. Rockauto offers a variety of starter solenoids but I doubt these are LT-5 specific.
So what would be a correct replacement part?

Also, I intent to stock a NOS Delco Remy starter as suggest in this forum (as offer on eBay...). Do these also have issues with unevenly wound coils?

[secondchance]

Contact nations auto electric and they can probably tell you which coil is correct. My experience similar heat soak situation turned out to be contacts.
I replaced the plunger while at it.

http://www.nationsautoelectric.com/densoparts.html

[Paul Workman]

Originally Posted by secondchance

Contact nations auto electric and they can probably tell you which coil is correct. My experience similar heat soak situation turned out to be contacts.
I replaced the plunger while at it.

http://www.nationsautoelectric.com/densoparts.html

I agree w/ the notion of contacts as the probable issue. In the 13 years I've read this site almost daily, I don't recall anyone mentioning fixing a DNS (starter fault, in this case) due to a coil issue. However, the internal high current solenoid contacts has often been the source of the DNS problem - guessing maybe 90+% of the time - apparently according to posts on this page.

Matt: However, use CAUTION when buying a new plunger (armature) to be sure the plunger pin is the SAME LENGTH as the stock one. If it is short or longer, the pinion gear only partially engages with the ring gear - resulting in only a portion of contact between pinion/ring gears. This is can eventually lead to broken teeth - primarily on the ring gear requiring a transmission pull at minimum to replace.

*NOTE: The most common "DNS" due to the starter is the copper electrical bridge (ring) on the solenoid often gets pitted and surface burns. At first it is just a minor aggravation. But soon it worsens to become a major "DNS" issue even if the solenoid "clicks" when the key is turned. However, restoring the surface of that copper ring is easily done in about 5 minutes or so with a piece of 150 to 200 grit emery cloth or sandpaper. Brightening up that ring will restore the function without worry about getting the right length of pinion plunger in the Denso repair kit.

[Matt B]

Not yet, but I pulled the list of no start candidates from the forum and will now start eliminating them. However this particular case is 99% heat soak based. She never had any issues when cold. This case happened after about 30 minutes of idle + another 30 minutes of shut down. And it reversed after about 2 hours of cool down with hood closed.
But you're right, clutch switch and VATS resistor are next in line.

[Paul Workman]

Yes, I agree with the notion the clutch safety switch issue. On the 90-92 years, ALL of the solenoid current passed through that switch (purple wire). But, in 93-95 cars, a relay is used to handle the high (solenoid) current and the safety switch only triggers that relay.

Below I've posted a diagram of the relay circuit (modification) which upgrades the 91-92s to (essentially) that of the 93+ circuit. The details of the modification are pretty plain to see from the diagram. However, "Dynomite" has a write-up in his SOLUTIONS sticky that details the installation.

OR...you can install a bypass across the (nanny) safety switch. No relay is required, BUT if the clutch is not engaged and the transmission is in gear, the car will lurch and maybe even start the engine while in gear. (Personally, I have always been in the habit of holding the clutch down before turning the starter switch.)

Anyway...here's the auxiliary relay circuit (I designed and drew up 11+ years ago). Happy hunting!

[Matt B]

Thanks, both! I'll use that drawing an install a Relais today. Better eliminate those time bombs BEFORE they blow up...

[Matt B]

Thanks, looks very smart. I've been using similar setups in my older Chevrolets as well as the Lincoln to beef up the headlamps, boosting available voltage from typically between 9 and 11V to whatever the battery supplies. Makes a HUGE difference. So I guess this mod not only releases stress from the clutch switch but also provides an extra kick of energy to the selenoid. I already dug out a nice relay but due to yesterday's great weather I had to postpone the operation in favor of a few drinks with my wife on our patio

[Paul Workman]

Originally Posted by Matt B

I had to postpone the operation in favor of a few drinks with my wife on our patio

Well...we all have to make sacrifices. But, sometimes ya gotta do what ya gotta do!