Dead miss, stumped, Help!

tom3 · 11-11-2009, 07:15 PM

93 Vortec. Dead miss on number 6 cylinder. Tried a different plug and plug wire, dist. cap looks fine. Laid a plug on the engine with that #6 wire connected, good spark. Compression on that cylinder is good. Fuel pressure at about 60 key on engine off. Engine running fine otherwise. Is it possible for the poppet valve to stop up on one cylinder? Can it be cleaned out if so? Can I pull the upper intake, pull that line out, turn key on and get a spray, or would I get a spray? I'm really at a loss here, figured sure it was ignition. Son did say he ran it pretty low on gas the other day, not sure that would do anything?

00bluegtp · 11-12-2009, 02:40 PM

sounds like you have a stuck poppet. You might be able to clean it but ussually people have to replace the whole cpi unit.

SH-60B · 11-12-2009, 03:50 PM

Run it breifly with the plug wire disconnected, then check the plug. If it's not soaking wet with gas, it's not getting fuel. That's probably the case, because you have compression and ignition, the only thing left is fuel.

lesterl · 11-13-2009, 09:20 PM

X2^ Could pull the poppet out and hose the end down with some wd40 and gently rub with your finger to free it up possibly.

fastr68 · 11-14-2009, 12:48 PM

hmm i didnt know you could maybe free the valves up like that hmm

never really looked at them that close, we just replace the units.

hmm

interesting

lesterl · 11-14-2009, 09:40 PM

Yeah, someone else said they had tried it and it worked, I dunno as I dont have that type of injection.

11-11-2009, 07:15 PM	#1
tom3 Registered User Join Date: Oct 2002 Posts: 444 Location: User is: OffLine	Dead miss, stumped, Help! 93 Vortec. Dead miss on number 6 cylinder. Tried a different plug and plug wire, dist. cap looks fine. Laid a plug on the engine with that #6 wire connected, good spark. Compression on that cylinder is good. Fuel pressure at about 60 key on engine off. Engine running fine otherwise. Is it possible for the poppet valve to stop up on one cylinder? Can it be cleaned out if so? Can I pull the upper intake, pull that line out, turn key on and get a spray, or would I get a spray? I'm really at a loss here, figured sure it was ignition. Son did say he ran it pretty low on gas the other day, not sure that would do anything?
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11-12-2009, 02:40 PM	#2
00bluegtp Registered User Join Date: Jul 2009 Posts: 167 Location: User is: OffLine	Re: Dead miss, stumped, Help! sounds like you have a stuck poppet. You might be able to clean it but ussually people have to replace the whole cpi unit.
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11-12-2009, 03:50 PM	#3
SH-60B Registered Neanderthal Join Date: Nov 2007 Posts: 2,749 Location: Meriden/CT/USA User is: OffLine	Re: Dead miss, stumped, Help! Run it breifly with the plug wire disconnected, then check the plug. If it's not soaking wet with gas, it's not getting fuel. That's probably the case, because you have compression and ignition, the only thing left is fuel.
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11-13-2009, 09:20 PM	#4
lesterl Wire Splicin Fool :-) Age: 30 Join Date: May 2008 Posts: 5,064 Location: Harrisonville, MO User is: OffLine	Re: Dead miss, stumped, Help! X2^ Could pull the poppet out and hose the end down with some wd40 and gently rub with your finger to free it up possibly.
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11-14-2009, 12:48 PM	#5
fastr68 easterwabbit Join Date: Sep 2002 Posts: 713 Location: Lincoln, IL User is: OffLine	Re: Dead miss, stumped, Help! hmm i didnt know you could maybe free the valves up like that hmm never really looked at them that close, we just replace the units. hmm interesting
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11-14-2009, 09:40 PM	#6
lesterl Wire Splicin Fool :-) Age: 30 Join Date: May 2008 Posts: 5,064 Location: Harrisonville, MO User is: OffLine	Re: Dead miss, stumped, Help! Yeah, someone else said they had tried it and it worked, I dunno as I dont have that type of injection.
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