Anyone have the plug wiring orientation for 351 v6

[purzell]

I might be searching Jolly's wrong. I need a picture of where the plug wires go from distributor to plugs in the 351 V6 motor. Can someone post that up?

I have attached a photo from my service manual and one of my engine. My friend put on the wires while I was at the auto parts store. If I'm looking at everything correctly, it looks all wrong to me. But I find it hard to believe that it's all put together that incorrectly, but maybe it is.


Symptoms I am experiencing: hard starting, backfire through carb (sometimes with fire), hard to keep running. Once warm though, will idle ok.

And am I looking at the right diagram for my motor?

[slorio]

Purzell:
Firing order looks okay according to the manual. You also have the firing order on your intake in front of your carburetor. Is it also 1-6-5-4-3-2?

Did the truck run okay before the wires were changed? What else was done at the same time as the wires?

Have you tried a timing light to see if the timing marks line up with the spec in the manual? I would try that next. Also, did you change the points as well as he the wires or move the distributor? A check of the point gap and/dwell angle if you have a dwell meter would tell you if you have points are closed.


I hope this is helpful.
regards,
Steve
New Orleans

[RockTonka]

Maybe these will help a bit...

[purzell]

At the same time as the wires we did points (not unipoints,) contacts, plugs, cap, rotor.

This is a new rebuilt carb. Adjusted timing and it's "pretty darn close".

But to be honest it hasn't run long enough to really tune it up, especially the carb. Since it idles when warm we can't seem to address the cold start and backfire through the carb issue. If we start it and stay on the gas until it's warm, and not let it pop and stall, then it will run.

That's why I started to get concerned about valves.

I do seem to have eliminated the vacuum leak I had under the carb by replacing the adapter plate with a better one.

I was hoping for an easy answer like a plug is wired wrong. Yeah, I'm a mechanical idiot so the picture in the book and the actual job look different to me. To my eye it looks like none of the numbers correspond.

[slorio]

purzell:
Next thing I would do is a compression check on each cylinder. Good cylinders will have approximately 125 lbs/sq. in. Let us know what the compression is for each cylinder.
regards,
Steve
New Orleans

PS Did you also post via the 6066gmcguy.org website?

[purzell]

Compression test results:
1: 45
3: 120
5: 110
2: 0-10 ( re-tested, got 0)
4: 120
6: 120
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[purzell]

I did post in the GMC site but Yahoo kicked me off and I cant seem to get back on. Sorry for double post.
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