GMPD4106 Starting Problems

Fred Mc · August 30, 2016, 04:48:55 PM

Ive had starting problems in the past which results in the motor not wanting to start once its warmed up (180 deg) Starts great when cold and I had to prime the filters a few days ago requiring turning over for 30 seconds or so with no problem. But when its warm and you press the starter button you can hear the solenoid clic in and it maybe turns engine over 1/4 turn but thats it. Wait 2 hours and its fine.

Some time ago I moved the batteries from the original place (2-8D's) to the old a/c compressor location (3-850 cca batteries) which puts the batteries closer to engine.Cables are about 5 feet long and go directly to the starter. I just bought 3 new 850 cca batteries and cleaned all the connections. I even hooked up my truck which has 2 of the same batteries(850 cca)for a total of 5 and it didn't make any difference.

Any ideas.

Thanks

Fred

chessie4905 · August 30, 2016, 05:51:15 PM

Maybe it's time to pull and check the starter.

Raymond smith · August 30, 2016, 06:32:58 PM

Sounds like starter to me. Warm it up with a heat gun when its cold. If it acts up you will know for sure. Just my nickles worth. Raymond

lostagain · August 30, 2016, 07:32:11 PM

Fred what bus, engine and starter? Can't read your mind... I had that problem a few years ago with my 6V92. Turned out to be corroded connections. Check and clean all connections between batteries and starter. At least you will know that it is good.

JC

lostagain · August 30, 2016, 07:33:46 PM

I see now it is a 4106. 8V71?

JC

Fred Mc · August 30, 2016, 09:06:16 PM

Yes, 871

Delco remy starter.

TomC · August 30, 2016, 10:12:32 PM

I had the same problem-started fine when cold, but just clicked away when hot. Discovered the ground cable at the starter was loose-problem solved. I know it's hard to get to, but check the big cables at the starter. Good Luck, TomC

chessie4905 · August 31, 2016, 05:12:33 AM

Also check if it has a bulkhead stud where wire is connected on both sides. They can get corroded.

OneLapper · August 31, 2016, 09:25:23 AM

It's more than likely the starter. Ive had the same symptoms.

Here's why: As the starter warms up with the running engine, the insulation on the magnets loses it's ability to insulate, so electrical power is shorted to the starter housing instead of spinning the motor.

I once had a shop try to repair the same starter several times with this problem. Lousy shop. I took it to a different shop and he pin pointed the problem within minutes. I took the same starter out three times in 4 weeks. I was installing the repaired starter at 11pm the night before a week long 1000 mile camping trip.

luvrbus · August 31, 2016, 10:57:05 AM

A bad solenoid will give you the same symptoms too they start going bad it won't carry the 900 amps needed for that starter just replace the starter and solenoid but don't buy a rebuilt solenoid it is not worth the few bucks you save

Utahclaimjumper · August 31, 2016, 11:25:29 AM

Those starters do not have "magnets" they are field coils. Most of the problems with starting an 8V71 can be explained with Red Riders latest experience with this same issue.>>>Dan

Red Rider · August 31, 2016, 12:04:59 PM

I was having a problem with the starter hanging up. That situation made a very short life of two mt 40 starters. I tried to buy a new starter however the only one NAPA could fine was in Tenn. I took all my core and melted parts to a place called Interstate Rebuilders in St George Utah Since my starter is CCW they had to "build " me a unit. We went with the MT 42 rather than the 40. It was a little bit lighter and had a more favorable rotation so the intallation was more user friendly.

Acquiring the parts took two days, meanwhile my 4106 was parked in the Dixie Nat Forest unable to start. After the second day the shop called to say my stuff was ready' except they asked which side of the starter did I want the supplimental solenoid mounted? I thought they had the wrong customer on the phone. I went to pick up the unit and very pleasantly found that this outfit equips all their starters with a secondary solenoid that only takes 2 amps to pull in the solenoid rather than the OEM 40 amps. It cost $50.00 however it stops low voltage to the disk in the original solenoid which arcd together causing it to hang up.

I realize this doesn't help with the " cold or hot" situation but may help others who have marginal ampacity with old wiring in their bus.

luvrbus · August 31, 2016, 12:32:58 PM

The newer MT 42 starters use a semi solid link solenoid it takes very little amps to engage, they also have over crank protection.To bad you lefty guys cannot buy the MT 39 that is starter even Mikey could pickup.FWIW Delco tell you to use a heat shield if you are within 2 inches of a heat source like the manifold on the 8v71 in GM bus

CrabbyMilton · August 31, 2016, 01:02:44 PM

Are the starters you guys are talking about the original direct drive or newer gear reduction type.
More and more are moving toward the gear reduction and even vehicles built before CHRYSLER introduced that type of starter in 1962 can be refitted with them.
Less current and more starting torque was the reason for this type of starters appeal.

luvrbus · August 31, 2016, 01:08:40 PM

The 39 is a gear reduction starter the 42 is a direct drive,the 39 is by far the better starter low voltage doesn't seem to affect the 39 vs the 42 but they don't make a left turning 39 and that is too bad and will probably never make one because there is no market for it