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Author Topic: Starter Hesitation....  (Read 2828 times)
Iver
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« on: April 23, 2009, 01:29:34 AM »

     I just changed a leaking fuel fitting as Jack suggested and it worked great.  Now I have developed a slight hesitation in getting the starter to engage.  Both the front and rear starter switches act the same.  When I push the button in front or throw the switch at the rear, it takes about 3 tries before the starter spins the engine. The first couple of tries act as though the battery was low, (they are fully charged), the starter tries to spin but then nothing.  On the third try it spins and the engine fires right up.
     Are there other relay solenoids other than on the starter itself that could be causing the problem?
       Thanks,  Iver.
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« Reply #1 on: April 23, 2009, 01:48:41 AM »

Does your system have a fuel pressure switch in the starter circuit. Perhaps you disturbed the connections when you made the repairs.
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« Reply #2 on: April 23, 2009, 02:49:57 AM »

Or maybe a bad ground.

~Paul~
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« Reply #3 on: April 23, 2009, 03:57:20 AM »

Here is the proper way to diagnose your problem as per Gerald Jenkinson, the Grand Poobah of diagnostics.

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« Reply #4 on: April 23, 2009, 05:19:04 AM »

I would pull all your grounds in the engine compartment and sand them shiny. Those things get really corroded.

it is a dirty job though...

Rick
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« Reply #5 on: April 23, 2009, 06:22:09 AM »

Sorry... forgot to suggest that you do the leads to the starter as well.


hope this helps.

Rick
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« Reply #6 on: April 23, 2009, 06:30:34 AM »

I think Paul & Rick have this one. We were getting the LUG LUG LUG with no start on our 8v92. Checked the Batts.=Full. Found a loose ground cable @ the batt. ground. Went ahead and cleaned and tightened all the batt. conections. Now it starts with a touch. MAN, that Big D sounds good. I got it Bad!!! Grin Grin Grin All the Best, M&C
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« Reply #7 on: April 23, 2009, 09:42:25 AM »

As other said, check ALL the connections.  Look for one that is hot after starting.  What is likely happening is the first couple tries are heating up the bad connection causing it to swell and tighten up just enough to work.  Soon it won't.

Good luck
Don 4107
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« Reply #8 on: April 23, 2009, 10:24:47 AM »

A bad connection will get hot, use an infrared thermal temp gun and point it on any termination, this includes all distribution panels including your house system. It's also a good idea to tighten all terminals once a year, electrical current does strange things to wiring and terminals, including all grounds. Keep the smoke in! Wink

~Paul~
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« Reply #9 on: April 23, 2009, 11:35:05 AM »

Did ya get the part about the poor connection getting hot? Huh Roll Eyes Cheesy

I think the most probable connections to go bad are internal to the starter.....1 and 2?  The next are in the relay.

If you don't have a thermal gun...get one.

Really important here:  Get some silicone grease like the stuff they use for spark plug boot release or cheaper but just as good SILICONE GREASE and coat all the connections with the stuff before you finish the connection.  You will never have this problem from that component again.  Toy pasks their light bulb sockets with the stuff to preserve the good contact you get when the parts are new.

John
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« Reply #10 on: April 23, 2009, 02:58:17 PM »

If all the above fails - try load testing the batts - how old are they? FWIW
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« Reply #11 on: April 23, 2009, 03:24:36 PM »

Hello:   Dont forget to check the connection behind the engine below the rail right side looking at the engine from the rear. From that connection one wire goes foward to the batteries; one to the starter; and one to the alternator.
   Regards and happy bussin  mike   
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Iver
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« Reply #12 on: April 23, 2009, 08:39:46 PM »

Thanks everyone for all the advice.  The 8-d's are new. Pretty sure the fuel pressure switch is undisturbed.  I will start checking all grounds as a first step.
            Iver.
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« Reply #13 on: April 23, 2009, 09:05:39 PM »

I agree with Tony.

If you just worked on the fuel system and the starter worked ok just before this work you probably have done something to the fuel pressure system. Not a lot of mystery there.

However, if it was a long time since you used the starter before repairing the fuel leak it is probably electrical connection corrosion.

There is also a starter relay in addition to the starter mounted solenoid which is small and often fails or doesn't work because of corroded terminals. This is usually the best place to look first because you can easily jump it with a small wire.
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« Reply #14 on: April 24, 2009, 12:19:28 AM »

Gus,
   Actually I had the problem developing before the fuel fitting repair.
Where is the other starter relay that you mentioned?
    Thanks, Iver
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« Reply #15 on: April 24, 2009, 04:46:08 AM »

Gus,
   Where is the other starter relay that you mentioned?
    Thanks, Iver
Should be in the rear electrical panel. Sorry, I can't be more specific, but I don't see you bus make or model listed.  Jack
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« Reply #16 on: April 24, 2009, 05:04:19 PM »

You said "Now I have developed a slight hesitation in getting the starter to engage." so I assumed it was a new problem, sounded that way to me.

As Jack says, knowing what bus you have will help find the relay. If it isn't an older GMC I can't tell you but someone else can.

Make and model should be in every post. Someday maybe it will be automatically included in each post.
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« Reply #17 on: April 24, 2009, 05:08:01 PM »

IMO don't bother looking for a panel relay.  Your first post said the starter engages and tries to turn the engine but it takes a couple of shots before it manages to spin it.  If the primary relay was the problem the starter wouldn't engage at all.  Go ahead and look for the relay just so you know where it is but don't bother trying any troubleshooting involving it because that isn't where the problem is.

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« Reply #18 on: April 24, 2009, 07:07:39 PM »

Bob,

You're probably right but if the relay has burned secondary contacts the solenoid won't get enough power or if the relay primary connections are badly corroded the same thing will happen, the relay secondary contacts won't stay together.

I always like to follow these events having had my share of them with both relay connections and battery cable connection corrosion. Never have had a solenoid problem.
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« Reply #19 on: April 24, 2009, 11:49:32 PM »

Sorry,  the coach is a MCI-9.  I was having problems with the starting before the fuel fitting cracked.  I haven't had a chance to check all the cables and grounds and will post again when I see if that resolves the problem.
         Thanks, Iver.
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« Reply #20 on: April 25, 2009, 04:13:44 AM »

    We had a fuel pressure switch fail several years ago.  We had similar symptoms.  Apparently, the contacts in the pressure switch had become pitted and several attempts caused enough heat build-up in them to make them work.  This can be diagnosed by bypassing this switch with a 12 gauge jumper wire between the switch contacts. or switch contact & good ground (depending on whether your switch has 1 or 2 contacts). Jack
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« Reply #21 on: April 25, 2009, 07:52:34 AM »

Yes, fuel pressure switch in the starter circuit is a consumable.

Unless a busnut knows its age, buy a new one and screw it in.

Another obscure, yet crippling, preventive maintenance chore accomplished.

And another excuse to hoist a cold one.

happy coaching!
buswarrior
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Iver
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« Reply #22 on: April 26, 2009, 02:37:09 AM »


Jack,
My pressure switch has only one contact.  I assumed that when the pressure switch is working properly, and there is fuel pressure in the system, it prevents the starter from engaging.  So if the pressure switch is bad, it acts as though there is fuel pressure even when there isn't?  And prevents the starter from engaging?
Buswarrior,  Cheers..... I'll get a new switch just in case.....
               Iver.
     
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« Reply #23 on: April 26, 2009, 05:17:56 AM »

Jack,
My pressure switch has only one contact.  I assumed that when the pressure switch is working properly, and there is fuel pressure in the system, it prevents the starter from engaging.  So if the pressure switch is bad, it acts as though there is fuel pressure even when there isn't?  And prevents the starter from engaging?
Buswarrior,  Cheers..... I'll get a new switch just in case.....
               Iver.
   
    If the contacts inside the switch are pitted, the problem can be intermittant.  It is a electrical problem, not a mechanical (pressure) problem.  Put a jumper wire from the terminal to a good ground.  If the hesitation is no longer occuring, replace the switch.  If the hesitation is still occuring, the problem is something else.  Jack
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