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Old 08-31-2012, 10:10 PM   #1
AusTx68
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Truck won't start after jetting carb

Carb is a Holley 670 Street Avenger. It's been on the truck a few weeks. Bought it new in the box. Over three weeks time I put maybe 50 miles on it. Checked the plugs and they read lean. Real lean. I drained and removed the primary bowl. Found it had two 63 jets. I added two 69's. Pulled the secondaries and found 72's. I left those in place. Put it all back together and now it won't start. Bowl levels are normal as viewed in the sight glass. Any guesses?
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Old 08-31-2012, 10:29 PM   #2
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Re: Truck won't start after jetting carb

Is the acc pump arm working right as in the squirter working?
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Old 08-31-2012, 10:47 PM   #3
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Re: Truck won't start after jetting carb

Yep. Everything appears to be working fine. It's strange. Even if I spray starter fluid into the carb it won't start. It's getting fuel and has spark. Doens't make sense.
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Old 08-31-2012, 11:46 PM   #4
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Re: Truck won't start after jetting carb

is it flooded pull some plugs see if they are wet. starting fluid i never use on gas engines can do to much harm than good.
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Old 09-01-2012, 12:02 PM   #5
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Re: Truck won't start after jetting carb

Sounds flooded to me too...

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Old 09-01-2012, 01:10 PM   #6
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Re: Truck won't start after jetting carb

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Yep. Everything appears to be working fine. It's strange. Even if I spray starter fluid into the carb it won't start. It's getting fuel and has spark. Doens't make sense.
When did you check for spark?

If it was lean, and you never got it to start, how would the plugs get gas fouled?

It sure sounds to me that your not getting spark.
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Old 09-01-2012, 11:19 PM   #7
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Re: Truck won't start after jetting carb

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When did you check for spark?

If it was lean, and you never got it to start, how would the plugs get gas fouled?

It sure sounds to me that your not getting spark.
I also think it's a spark problem. The spark looks weak. It doesn't have that flash to it. I will put an ohm meter on the coil and see what I find.
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Old 09-02-2012, 05:22 PM   #8
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Re: Truck won't start after jetting carb

It appears the coil is bad. That's based on the following ohm readings.

BAT to TACH = .7 (good value)

BAT to Carb Button under cap = No reading at all. I understand this to be a short in the secondary coils. I removed the coil and took the same measurement directly on the coil. Also zero reading.

I'm going to get a new coil and see what happens. I will run the same measurements on the new coil before install.
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Old 09-03-2012, 01:33 PM   #9
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Re: Truck won't start after jetting carb

Well, the coil measurements didn't mean a thing. Guess you can't believe everything you read on the Internet. The new coil measured the same. I still put it in. Same results. I'm grasping for straws at this point. Spark looks weak. I have 12.4 volts at the dizzy. Drops to 10 when starting. Ran a 10g wire directly from battery to dizzy. Still not starting. I get a few pops but nothing more. So far I've spend a solid 3 days on the problem. Something that I would normally assume a simple fix has turned into major frustration. At this point I'm going to just walk away and stop messing with it before I put a bullet in it.
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Old 09-03-2012, 05:31 PM   #10
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Re: Truck won't start after jetting carb

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Well, the coil measurements didn't mean a thing. Guess you can't believe everything you read on the Internet. The new coil measured the same. I still put it in. Same results. I'm grasping for straws at this point. Spark looks weak. I have 12.4 volts at the dizzy. Drops to 10 when starting. Ran a 10g wire directly from battery to dizzy. Still not starting. I get a few pops but nothing more. So far I've spend a solid 3 days on the problem. Something that I would normally assume a simple fix has turned into major frustration. At this point I'm going to just walk away and stop messing with it before I put a bullet in it.
Go back to basics.
Check timing

You said plugs were real lean,aka: insulators were white ashy color, correct?

Points or HEI? Points, check dwell. contacts OK?

If all else fails, put old jets back in to check if this is the cause. (I doubt it)
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Old 09-03-2012, 06:23 PM   #11
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Re: Truck won't start after jetting carb

AusTx68;
Sorry to hear you are having Igntion system problems.
You might have better luck if you start a new thread over in the main "General Truck Forums-Engine and Drivetrain" section of the boards you will get more dedicated and possibly even expert help over there.
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Old 09-03-2012, 10:41 PM   #12
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Re: Truck won't start after jetting carb

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Originally Posted by biggestjohn View Post
Go back to basics.
Check timing

You said plugs were real lean,aka: insulators were white ashy color, correct?

Points or HEI? Points, check dwell. contacts OK?

If all else fails, put old jets back in to check if this is the cause. (I doubt it)
Right. Insulators were white ashy color. It's HEI.
At this point I'm thinking to pull the HEI out of my 87 and see what happens. If that doesn't work I'll pull the carb too. Typically I would never cannibalize another truck for the sake of testing but this has be scratching my head.

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AusTx68;
Sorry to hear you are having Igntion system problems.
You might have better luck if you start a new thread over in the main "General Truck Forums-Engine and Drivetrain" section of the boards you will get more dedicated and possibly even expert help over there.
I actually started there. After 3 days, 28 views, and 1 response (me), I moved it here and got a better response.
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Old 09-03-2012, 11:02 PM   #13
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Re: Truck won't start after jetting carb

posible hei module gone bad ?
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Old 09-04-2012, 09:09 PM   #14
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Re: Truck won't start after jetting carb

I'm happy to report the truck is now running with all the same parts. I think the problem was in the plug that connects the cap to the dizzy. The plug has 3 wires with female spade connectors. It appears the spade pushed back into the plug and wasn't making a good connection. At least that's my guess. It started after I made sure they were solidly connected. I'm glad it's running but I have a lot of time to make up.
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Old 09-05-2012, 05:41 PM   #15
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Re: Truck won't start after jetting carb

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I'm happy to report the truck is now running with all the same parts. I think the problem was in the plug that connects the cap to the dizzy. The plug has 3 wires with female spade connectors. It appears the spade pushed back into the plug and wasn't making a good connection. At least that's my guess. It started after I made sure they were solidly connected. I'm glad it's running but I have a lot of time to make up.
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Your luck sounds as bad as mine.
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