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#34 hesitation and missing between 2000 & 3000 rpm

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GTP1960

GTP1960

Jedi Knight
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GTP1960 said:
I know I've recently mentioned this, but it has me stumped.

The strange thing is the hesitation start after about 45min. of open road driving & gets progressively worse, until I feel lucky to make it back to the garage.
today, I warmed the car up before the test (I had already tuned the carbs, to balance the mix and airflow, independently and sync'd ....I've done this so many times, now, it feels like i know what i'm doing)

and the drive started off great, all gears & speeds.
temp remained good and stable.
oil pressure was a comfortable 55-65psi.
ran strong under load...... until about 45min. into the drive (& warm up)
then it would hesitate and miss noticeably in the range between 2000 & 3000 rpm in any gear, or overdrive.

below 2000, with no acceleration,.........fine
above 3000 or heavy foot acceleration , seemed to thrive.

The ignition system is a new flamethrower III with new 25D distributor.
The coil is new 45k volts recommended with the Flame III.

I'm thinking my new electronics might be my problem.
I'm going to put the old coil back in next.

BTW: regarding fuel:

my electric fuel pump is located under the left rear shock (about 8" from the exhaust pipe)
I run it at 2psi using a regulator.

I'm using 93 pure gas..........but i don't want to eliminate bad gas as a possibility.

This is a mystery I'm getting real tired of.

any ideas or insight appreciated.
Guy
Click to expand...

Well I'm happy to say it was my new coil after all.
the new Flamethrower III, 45k volt coil was great for starting and quicker acceleration, but apparently it became erratic when it got to hot.
(perhaps moving it's location away from the block would fix that, or upgrading the sp lines to a compatible set, But that is a test for another day)

after switching back to my old (gold colored) coil, my engine troubles disappeared.
(the pertronix flamethrower III ignition system works fine with the old coil)
lost a little pep.....have to grind it a few extra seconds to start, but she runs like a champ again.

i did check the spark plugs & at least I can say the reading makes me think the carbs are balanced & sync'd.
So I write another headache up to a learning experience.

Now to see if I can get my $40 bucks back from pertronix (fat chance)
thanks for reading


 
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