Soooo, I just added another brick to the collection ⏠ 242 na-b23] and cannot get the dang thing to idle smoothly. This is after swapping in a known good AMM from a well running b23, replacing the AMM to throttle body hose, cleaning the TB and new gasket, new intake manifold gasket, checking all vac hoses, cleaning the idle air motor, and giving the air box a new thermostat with cleaned/oiled flapper workings... Wiring harness is superb compared to some we've all seen and the TPS clicks like it should...

It's worse when warm.

Um, now what?

Interesting: noticed 3000 rpm brings a sudden jump in power [and quite a peppy turbo-esque one at that], sub-3k is a tich on the sluggish side side of normal; could this engine have a custom cam grind of some kind that I wasn't informed of and the idle just gets to stay funky? Or is something else still miscalibrated?

Ideas?
Thanks.

Your turboesque shifting is probably from the adjustment of the kickdown cable. My 84 B23F is like that as well after I tightened the cable setting.

Erich
Ottawa Canada

Ah, forgot to mention, m46... No kickdown, thanks though. (The last brick that came to me with an autobox got fixed into a stick anyhoo.)

Rob

Check the injectors for leaks, first of all. Even if there are no leaks at the seals you could have one or more dirty injectors causing the problem. A power flush is probably in order in any case, especially if you are on the original injectors after 20 years.

It could also be one of the usual suspects - spark plugs or especially plug wires, air filter, cap/rotor, some basics like that. You didn't mention whether or not you got to those things yet.

AH, will do. Yep, the usuals were tended to first, then I dove into the faq and proceeded further. I spaced the injectors as I've been accustomed to k-jet for so long just plain working.

Thanks
Rob

have you checked all your injectors? disconnect one at a time and see if the your idle changes differently with one of them. I have an 83 and the idle was "surging" just slightly and I tried all the usual suspects. Finally I noticed after removing one injector connector at a time that the idle went to a consistent sputter with surge on three of them, but on the bad injector the surge stopped as the sputter started. It also seemed to suddenly kick in additional power at higher rpm. good luck

Will try the disconnection this eve, thanks!

Rob

Since you note a "sudden" surge of power around 3K, I'm willing to bet that you have an A or K cam in there. My K cam makes the car always idle just a little lumpy....not smooth like the M cam before it. If you take off the valve cover and rear cam bearing cap and use have a mirror, you could probably weasel it back behind the very end of the cam and see the letter etched into it without taking the cam out. Then you'd know if that was the reason and not spend too much time trying to fix an idle that might not be fixable...just a thought. You'll probably need a new valve cover gasket though. Good luck,

Nate Gundy
--
'86 240DL sedan, 260K miles, M46, K cam, 25/23mm sways, 260 front and wagon rear springs; http://valvespringcompressor.weblogs.us/

Thanks! I was wondering where the marking would be on the cam. Didn't want to pop the valve cover until I had an idea of where to look for what.

Rob