blazer ignition problems, i think - Pirate4x4.Com : 4x4 and Off-Road Forum

baldredhead · 07-07-2005, 09:39 PM

Hi

This is going to be a little long, sorry

I acquired an 86 k5 blazer about a month ago and it ran pretty well, though i only got to drive it about 15 miles before parking it for a month. It has been thoroughly desmogged and kluged in innumerable ways. I tried at least starting it a few times in the mean time, though only managed to find time to drive around the block. No problems, i think.

Yesterday i decided it was about time to bring it the rest of the way home, a whopping 6 miles. It made it about 3 blocks before refusing to start. During the three blocks it would run ok till i had to stop, then cut out and immediately restart. It was at one of these stops that it didn’t come back.

Today i replaced the distributor cap, rotor, coil, plugs and wires. I presume the timing is good enough as it did run not too long ago. I forgot to reconnect the plugs in the dizzy for a minute or two of cranking, and it almost caught when i did reconnect them. It didn’t stay running so i tried grounding a spare plug attached to a wire to the intake manifold and it didn’t spark at all.

The carb is a holley double pumper that is probably doing too much pumping. When i removed the old spark plugs they were dark sooty black.

So, my theory is that for whatever reason i’m not getting consistent spark. I’m not sure where to start, i’m not a good electrical person, and any help is much appreciated.

thanks

charlo · 07-07-2005, 10:18 PM

Your original problems sounded fuel related to me but they could be anything. Cranking the engine with no wires attached to the dizzy can burn out a coil but might take a lot. You shouldnt have to ground a plug, a healthy coil will produce a spark you can see directly from the distributor cap to the plug wire up to an inch away. Sooty plugs means rich. Hope this helps.

Charlo

baldredhead · 07-08-2005, 08:26 AM

Charlo

i had to ground a plug because the boot on the plug wire won't pull back so i can see the spark.

i probably have two issues

edit:
something i forgot to mention origianlly is that one or two of the times i did get it started i pulled the negative lead from the battery the idle speed picked up and in general the idle improved. does that mean anything?

85blackdiamond · 07-09-2005, 06:04 PM

i'd think maybe ignition module, just dont get an accel one, went through 2 in 100 miles.

baldredhead · 07-11-2005, 10:45 AM

daaaaarhg

tried that last night, a generic one from NAPA but no luck. i'm about to haul out the elephant gun and put this truck out of my misery

07-07-2005, 09:39 PM	#1 (permalink)
baldredhead Registered User Join Date: Dec 2003 Member # 25305 Location: SF bay area Posts: 48	blazer ignition problems, i think Hi This is going to be a little long, sorry I acquired an 86 k5 blazer about a month ago and it ran pretty well, though i only got to drive it about 15 miles before parking it for a month. It has been thoroughly desmogged and kluged in innumerable ways. I tried at least starting it a few times in the mean time, though only managed to find time to drive around the block. No problems, i think. Yesterday i decided it was about time to bring it the rest of the way home, a whopping 6 miles. It made it about 3 blocks before refusing to start. During the three blocks it would run ok till i had to stop, then cut out and immediately restart. It was at one of these stops that it didn’t come back. Today i replaced the distributor cap, rotor, coil, plugs and wires. I presume the timing is good enough as it did run not too long ago. I forgot to reconnect the plugs in the dizzy for a minute or two of cranking, and it almost caught when i did reconnect them. It didn’t stay running so i tried grounding a spare plug attached to a wire to the intake manifold and it didn’t spark at all. The carb is a holley double pumper that is probably doing too much pumping. When i removed the old spark plugs they were dark sooty black. So, my theory is that for whatever reason i’m not getting consistent spark. I’m not sure where to start, i’m not a good electrical person, and any help is much appreciated. thanks __________________ -bryan 89 fj62

07-07-2005, 10:18 PM	#2 (permalink)
charlo Registered User Join Date: Jan 2002 Member # 9357 Location: Mojave Posts: 1,200	Your original problems sounded fuel related to me but they could be anything. Cranking the engine with no wires attached to the dizzy can burn out a coil but might take a lot. You shouldnt have to ground a plug, a healthy coil will produce a spark you can see directly from the distributor cap to the plug wire up to an inch away. Sooty plugs means rich. Hope this helps. Charlo __________________ Scrap metal with a chevy logo in front. BB,FI,1T,

07-08-2005, 08:26 AM	#3 (permalink)
baldredhead Registered User Join Date: Dec 2003 Member # 25305 Location: SF bay area Posts: 48	Charlo i had to ground a plug because the boot on the plug wire won't pull back so i can see the spark. i probably have two issues edit: something i forgot to mention origianlly is that one or two of the times i did get it started i pulled the negative lead from the battery the idle speed picked up and in general the idle improved. does that mean anything? __________________ -bryan 89 fj62 Last edited by baldredhead; 07-08-2005 at 09:37 AM.

07-11-2005, 10:45 AM	#5 (permalink)
baldredhead Registered User Join Date: Dec 2003 Member # 25305 Location: SF bay area Posts: 48	daaaaarhg tried that last night, a generic one from NAPA but no luck. i'm about to haul out the elephant gun and put this truck out of my misery __________________ -bryan 89 fj62

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07-09-2005, 06:04 PM	#4 (permalink)
85blackdiamond Registered User Join Date: Apr 2005 Member # 46123 Posts: 50	i'd think maybe ignition module, just dont get an accel one, went through 2 in 100 miles.