Starting Issues Seriously Frustrated

[RumRunnerZ71]

Hey guys I have an '85 k10 that I'm having starting issues with and I'm completely stumped as to what my problem is. My starter seems to be the center of the issue but I don't know how to fix the problem or rather problems. The problems started with my starter not engaging the flywheel correctly so I figured i could just shim it in, the problem is when I get it shimmed it will work well for a while (anywhere from two cranks to three or four days) but then go right back to not catching the flywheel. I have had two completely different starters in it and both of them have the same issue. I thought that maybe the solenoids were bad on them so I grabbed one I know is good off of another I had laying around the shop and put it on and now the starter wont even crank. Also the in line fuse from the starter solenoid up into the cab randomly blows, usually after the starter goes through one of it's hard start spells. I checked the wire for a short and when connected to the starter it comes up as being shorted but when i disconnect it and test the wire is fine. I honestly have no idea what the culprit could be so I thought I would turn to you guys and see if anybody else out there has had similar problems. Thanks very much for any input.

[jeremyp]

im having a similiar problem ,seems on mine the outside bolt hole on the block is cracked, have you had any luck yet

[95BlackTahoe]

Sounds to me like it could be a bad spot on the flywheel...and on the times when that lines up with the starter, it does exactly what you are describing. I replaced one in a buddy's truck that had a few teeth out and was causing this same headache.

Shawn

[RumRunnerZ71]

Ok guys I know this is a pretty well dead thread but I'm gonna put my information up here anyway because I know I searched for hours and never came up with anybody who posted a solution. Indeed my flexplate/flywheel was missing teeth so I replaced that and put on a brand new starter at the same time. This solved the problem of turning over the engine. The truly baffling part for me though was the strange behavior of the electrical system. What ended up being the problem was that the wire running from the starter solenoid to the ignition switch had an in-line fuse on it which I had blown. To replace it I originally used a new blade type in-line fuse but found that it would blow nearly every time I tried to start the truck. The reason for this is the actual way that the two types of fuses work. Blade fuses are designed to blow immediately when they experience amperage above that which they are rated for. The old style in-line fuses however consist of a small section of smaller gauge wire that actually burns up when exposed to amperage above it's rating. This is important because this allows these type of fuses to actually withstand prolonged exposure to the higher amperage without blowing, so if a starter solenoid for whatever reason puts out a little too much amperage (a hard start-up for instance) the inline fuse can withstand this short exposure without blowing. I could have simply replaced it with a true old style in-line fuse but those are becoming increasingly hard to find and I found what I think is a much better solution. I simply put a 40 amp circuit breaker with an automatic reset in place of the in-line fuse. This way I get the security of the blade style fuse making sure nothing could get within the rest of the system van get fried but with the automatic reset restoring power to the line as soon as it drops to acceptable amperage. Anyway that's my fix and hopefully somebody somewhere will find this information useful as I know it caused me a great many headaches trying to figure out myself.

[shanesaw]

I had a similar problem with a starter and a flywheel in a jimmy I bought, turned out the flywheel was for the truck and the starter was for a car. Most of the time it would catch and work fine. The rest if the time if seemed like a shim issue. Took forever to figure out.

[RumRunnerZ71]

Yea that's the one downside to having everything fit everything else on these gm vehicles you get one guy in there before you trying to save money and you can spend a fortune trying to fix something that really isn't broke