Home » Public Forums » GMCnet » Ignition / starting issues
| Ignition / starting issues [message #263132] |
Wed, 01 October 2014 21:54  |
mickey szilagyi
Messages: 273
Registered: January 2013
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Hello everybody,
All has been great lately and we were about to go on our last trip for the year before putting the coach away for the winter. Went to move the coach and to our surprise, it will not start. Turns over fine, but no fire, but is getting plenty of gas as the carb is soaked with gas. I let it sit for a while, and shot some starter fluid in just to see, and again no fire. So I started at the top of the list checking the ignition components: Checked the cap and rotor (which were recently replaced with new) and they look fine. Replaced the coil with a spare, no luck. Replaced the ignition module, no luck. So now I'm back to square one and give up for now. I have not removed a plug yet to check for spark, but that's next for tomorrow. What other tests can I do to check the ignition system? I'm up for any suggestions as I'm completely stumped. We just had the coach out last weekend and it was doing fine.
Thanks as always....
Mickey
Mickey
1977 Kingsley, 403, Lansing, MI
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| Re: Ignition / starting issues [message #263188 is a reply to message #263144] |
Thu, 02 October 2014 18:19  |
mickey szilagyi
Messages: 273
Registered: January 2013
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OK I have done some additional tests, and confirmed ignition IS OK. There is 12V going in to the distributor with the ignition key on. I also hooked up a timing light and it's showing a spark through the wires. So based on that I started looking more at the carb. I've found that it seems to be severely flooded as I could see gas pooled under the carb in the intake area. I pumped out everything and am letting it sit in hopes it will dry out. The question is, I have no idea how that much gas got down there. I cranked it without pumping the primer jets and it almost looks like gas is pooling up again. I'm still looking this over but open to any suggestions... thanks again.
Mickey
1977 Kingsley, 403, Lansing, MI
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| Re: [GMCnet] Ignition / starting issues [message #263193 is a reply to message #263189] |
Thu, 02 October 2014 18:58 |
mickey szilagyi
Messages: 273
Registered: January 2013
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James Hupy wrote on Thu, 02 October 2014 18:28Sunk Float. Had a bunch of trouble with 3 different floats on a 500
Cadillac in a GMC this summer on the route 66 rolling rally. Final cure was
a phenolic float. Ethanol fuel wreaks havoc on the new brass floats made
off shore.
Jim Hupy
Salem,OR
78 GMC ROYALE 403
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Yikes. But makes sense, I didn't think of that. I'll have to investigate that further. What surprises me is that I can't get this thing to fire at all. I sucked out as much gas as I could and then sprayed a couple shots of starter fluid down there and turned it over without priming it, but got nothing. But I guess if it's pushing that much gas through then that might be why. I really hope the cylinders are OK, I'm assuming it would take quite a bit for that to be an issue. I sucked out probably 2-3 ounces of gas.
Are you suggesting I get a phenolic float for this carb, if one is available? Thanks Jim.
Mickey
1977 Kingsley, 403, Lansing, MI
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| Re: [GMCnet] Ignition / starting issues [message #263195 is a reply to message #263188] |
Thu, 02 October 2014 18:54 |
k2gkk
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Registered: November 2009
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CHECK YOUR OIL IMMEDIATELY TO SEE IF IT SMELLS LIKE GASOLINE!
Yes, I am shouting a warning!
If it does, you should change the oil immediately and eliminate that gasoline leak (likely a stuck float needle) before running the engine!
A gas-oil mixture in the crankcase does nasty things to bearings in the engine! That stuff doesn't lubricate your engine worth a damn!
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> Date: Thu, 2 Oct 2014 17:19:39 -0600
> To: gmclist@temp.gmcnet.org
> From: mickey@apex-internet.com
> Subject: Re: [GMCnet] Ignition / starting issues
>
> OK I have done some additional tests, and confirmed ignition IS OK. There is 12V going in to the distributor with the ignition key on. I also hooked
> up a timing light and it's showing a spark through the wires. So based on that I started looking more at the carb. I've found that it seems to be
> severely flooded as I could see gas pooled under the carb in the intake area. I pumped out everything and am letting it sit in hopes it will dry out.
> The question is, I have no idea how that much gas got down there. I cranked it without pumping the primer jets and it almost looks like gas is
> pooling up again. I'm still looking this over but open to any suggestions... thanks again.
> --
> Mickey
> 1977 Kingsley, 403, Lansing, MI
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| Re: [GMCnet] Ignition / starting issues [message #263196 is a reply to message #263189] |
Thu, 02 October 2014 19:02 |
Otterwan
Messages: 946
Registered: July 2013
Location: Lynnwood (north of Seattl...
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James Hupy wrote on Thu, 02 October 2014 16:28Sunk Float. Had a bunch of trouble with 3 different floats on a 500
Cadillac in a GMC this summer on the route 66 rolling rally. Final cure was
a phenolic float. Ethanol fuel wreaks havoc on the new brass floats made
off shore.
Jim Hupy
Salem,OR
78 GMC ROYALE 403
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
How can ethanol "wreak havoc" on a brass float? Brass floats have been recommended for QJets for years.
1977 Birchaven, Lynnwood WA - "We may not be able to stop all evil in the world, but I know that how we treat one another is entirely up to us."
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| Re: [GMCnet] Ignition / starting issues [message #263202 is a reply to message #263195] |
Thu, 02 October 2014 19:40 |
mickey szilagyi
Messages: 273
Registered: January 2013
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k2gkk wrote on Thu, 02 October 2014 18:54CHECK YOUR OIL IMMEDIATELY TO SEE IF IT SMELLS LIKE GASOLINE!
Yes, I am shouting a warning!
If it does, you should change the oil immediately and eliminate that gasoline leak (likely a stuck float needle) before running the engine!
A gas-oil mixture in the crankcase does nasty things to bearings in the engine! That stuff doesn't lubricate your engine worth a damn!
Roger that, once the carb issue is addressed, we'll change the oil on the spot... I'm not even taking any chances at this point.
Mickey
1977 Kingsley, 403, Lansing, MI
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| Re: [GMCnet] Ignition / starting issues [message #263301 is a reply to message #263189] |
Fri, 03 October 2014 19:37 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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We had the opposite problem with aviation carbs. They released an Airworthiness Directive stating that we had to switch to composite (what ever that is) floats. A couple of years later we got another AD stating that we had to remove the composite floats and go back to brass ones again. I've only had one with a hole in it. It was on a generator. A little solder on the crack took care of the problem.
Who knows what is best at this point.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] Ignition / starting issues [message #263338 is a reply to message #263337] |
Sat, 04 October 2014 12:59 |
Otterwan
Messages: 946
Registered: July 2013
Location: Lynnwood (north of Seattl...
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mickey szilagyi wrote on Sat, 04 October 2014 10:40OK I'm in to the carb where the float is. However I'm stuck at the point where I remove the assembly that is just above the float itself. Including a pic below of what I'm talking about. How do I remove this in order to get down in to where the float is?
http://www.gmcmhphotos.com/photos/carburetor-repair/p56117-float-area.html
I noticed the float is already a phenol one, so I'm guessing this or the needle is the issue here. I'll just replace both since I'm in there.
Thanks again.
That black thing is just a "stuffer block" and should lift out easily.
1977 Birchaven, Lynnwood WA - "We may not be able to stop all evil in the world, but I know that how we treat one another is entirely up to us."
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| Re: [GMCnet] Ignition / starting issues [message #263339 is a reply to message #263338] |
Sat, 04 October 2014 13:03 |
mickey szilagyi
Messages: 273
Registered: January 2013
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Otterwan wrote on Sat, 04 October 2014 12:59
That black thing is just a "stuffer block" and should lift out easily.
That's what I thought too, but the assembly just above that stuffer block has to come out first somehow, and that's where I'm stuck at the moment. Thanks!
Mickey
1977 Kingsley, 403, Lansing, MI
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| Re: [GMCnet] Ignition / starting issues [message #263342 is a reply to message #263341] |
Sat, 04 October 2014 13:29 |
Otterwan
Messages: 946
Registered: July 2013
Location: Lynnwood (north of Seattl...
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It just dawned on me that if your power piston is stuck, that could be your whole problem. If stuck it can act like the secondaries were open all the time, even thought the air valve is closed. Thus flooding and popping.
"Jammed Power Piston:
Results in: Poor idle, rich idle, ineffective idle mixture screws, hesitations and stumbles.
Comments: The power piston can be jammed in either the full lean or full rich position, producing the same symptoms as an incorrect spring. You can test the power piston with the engine "off" by inserting a thin, long screwdriver down the bowl vent in the air horn. You should be able to depress the power piston and feel it pop back up. A jammed piston is usually caused by dirt entering the bowl, but can also be caused by carbon sooting up through the intake manifold from bad valves or valve timing problems."
1977 Birchaven, Lynnwood WA - "We may not be able to stop all evil in the world, but I know that how we treat one another is entirely up to us."
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