Ignition guru's have a look

Don W.

Don W.

Stab it and steer it
Check these DMs.

Look after the 2-3 shift. RPM goes flat. Also look at the RPM trace between first and second. See how it is jagged compared to off the line up to the first to second shift.

https://dl.dropboxusercontent.com/u/86797850/AutoLog_206.uni


Same with these only the truck continues to accelerate, sort-of .

https://dl.dropboxusercontent.com/u/86797850/AutoLog_208.uni

https://dl.dropboxusercontent.com/u/86797850/AutoLog_209.uni

https://dl.dropboxusercontent.com/u/86797850/AutoLog_210.uni

I'm fairly certain this is ign related but where? Except for the flat line in DM 06 I can feel it begin to miss a bit in the traps (highest load on the motor hence highest load on the ign.) So the question is.. module (or the dist itself), coil, wires are fairly new, plugs at .028 (haven't pulled them yet.)

I'm leaning toward module first then maybe coil, followed by dist itself, then wires. Mostly because I already have the other parts.

Thoughts, ideas, much appreciated.
 
It's just a six

It's just a six

Super Member
Re: Ignition guru's have a look

Close the gap on the plugs. Then try it out again.
Plugs could be too dirty.

What is your ignition set-up?
Stock, MSD, ???

Methanol really likes to snuff out the spark especially with boost.
 
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Don W.

Don W.

Stab it and steer it
Re: Ignition guru's have a look

Might be a day or 2 but I'll pull the plugs not doubt. Ign setup is stock dist, brand X module (I have 3), stock coil, wires new in April. MSD 6al w/2step. I have another stock coil and an MSD coil. Plus another dist. so I can throw parts at it for awhile...:roll:

Thanks
 
Don W.

Don W.

Stab it and steer it
Re: Ignition guru's have a look

OK, gaped the plugs today, .025. They looked rich but all very close to each other. In the past one bank would look rich and the other perfect.

Racing Wed. weather looks good. Did a test pull today, it went well but I have to shut down at 1000' so the real test will be Wed. (I'm doing right at 100mph at 1000' so faster on this road is spooky.):lol: BTW the 1000' is a real 1000'. I measured it off a couple years ago. I have 1320 marked also but I'm afraid to go that far.:rotf:
 
It's just a six

It's just a six

Super Member
Re: Ignition guru's have a look

Sorry to hear it's still not running good.

I know on my friends car, it would idle perfect, part throttle still fine, but @ WOT it would run like crap.

When I opened the hood in the dark I saw a blue light show looking @ the spark plug wires, most were bad.

Another friend had OHM out new MSD wires & they checked out too much resistance, sent them back & got a new set & the OHM's checked out with what MSD stated they should be.

Just saying, just because the wires or spark plugs are new or fairly new, does not mean they are in good working order. Not saying that is your problem, but could be a possibility.

Good luck Don.
 
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0966Sy

0966Sy

Code what?
Don, sorry to hear about the road block. How do you have your MSD box wired to the ignition module? I've recently diagnosed a similar problem on a friends truck with the same setup and it progressively got worse. I found a poor connection to the MSD/IGN module.
 
Don W.

Don W.

Stab it and steer it
Re: Ignition guru's have a look

MSD is wired using their P&P harness. It's disconnected now for diagnosing. It didn't make any difference anyway. Short of time today but I did get the module changed. Then it started, once. No 2 sec fuel pump. This has been a intermittent issue for awhile. This time I swapped relays and it works. Being an intermittent the jury is still out but I'll keep an eye on it. Will have to test later.

Thanks for all the suggestions.:tup:
 
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