Stumbling 1974 2.0...It's finally fixed. Post 63., Thanks to everyone who weighed in, embarrassing reason posted below... Options

[orthobiz]

9/17/19. My resistance numbers are good, my ability to read said number is bad! Paul

9/16/19 I removed the MPS because I could not be assured I was touching the leads appropriately after removing the plug...and what I found...Post 52

Paul

9/15/19 Another update:

Tested the vacuum on the MPS, it's fine. Am hoping to test electrically according to PBAnders site:

"If the vacuum test is passed, check the coil resistances. The primary coil is measured between terminals 7 and 15 and should measure about 90 ohms. The secondary coil is measured between terminals 8 and 10 and should measure about 350 ohms"

Is there a diagram of the terminals? Do I remove the unit to test it? Damn I'm such a newbie!

Paul

9/14/19 update:

My 1974 2.0 with EFI was running fine. Put in LED taillights, left the ignition on to test the blinkers and then the car started running poorly. Thought I fried my Pertronix, put a new one in, seemed to run fine for a day and then started running poorly again. I took some video today but it really doesn't show what is happening as felt in the seat of my pants, i.e. it stumbles but doesn't crack heads back and forth. A loss of power, maybe a bit worse when warmed up, mild surging that is disconcerting and annoying to say the least.

I disconnected the TPS and it didn't run any better. I am wondering if the TPS is bad, could the engine run poorly even if it is disconnected. In other words, does that totally rule the TPS out as the problem?

It just has to be something electric, I think. Should I replace the TPS just to see? I can't imagine going back to incandescent lights will help, it's stumbling with or without the LED lights on.

I'd rather not go back to points/condenser...

Sorry I'm so needy but I am puzzled to say the least!

Paul

Older posts follow:

Update on the update: I fried my Pertronix...see below.

Update: it's more like a hesitating stumbling, happening with or without cruising, that is, it also happens under acceleration. Original post follows:

My 1974 2.0 started bucking all of a sudden. Researching on the site, I'm thinking it's the TPS. Looked in George's Tech Tips 700 book and he advised disconnecting the TPS harness to see if the bucking went away.

To cut to the chase, it bucks especially between 2000-3000 RPM whether the TPS is connected or not. Mainly under light load, while driving and maintaining speed.

It seems to do this more when the engine is warming up, rather than when stone cold.

I am wondering if I should just replace the TPS board. Does the persistence of this problem after disconnecting the TPS rule it out as a cause? I don't feel like tearing into this unnecessarily.

It has a new late style fuel pump that is mounted up front last year, eliminating vapor lock. I've read here that low pressure can be the culprit, but would doubt it in my case.

Perhaps the temp change relationship implies a bad CHT sensor?

Any ideas on things I can easily check much appreciated.

Paul