xman

I own an 82 RX-7, and I seem to be having problems with my engine's idle during warm-up. I only seem to have this problem during cooler weather. The car starts well, then just before complete warm-up the car will die unless I give it gas. If it dies and I re-start her she usually runs just fine. All of my emission's equip. has been removed (rat's nest, acv, air pump, etc), and aside from the idle thing everything runs fairly well. I've tried adjusting my idle and mixture and I was wondering if there's any other angle I can look into. Any help would be much appreciated!

Rx7carl

Is this before the choke drops off? or after? And how did you adjust the mixture?

xman

It's before the choke drops off. Actually I forgot to mention that my emission control unit fuse (located under dash by the hood release lever) keeps blowing causing my choke **** to stop working. There must be a short somewhere, but I HATE electrical stuff, and have no clue where to look for a short, etc. I just keep replacing the fuse. Anyway, as far as the mixture, I just ran the engine until warm. At idle, turned mixture screw clockwise until the engine stumbled, then turned back counter-clockwise in small incriments until the engine ran well. Actually, it's running a bit rich I think, but I'm running with DLIDFIS and I heard that it's better to run a little richer. I don't think it's too rich, though I don't have an gas analyzer, and I don't have any emissions stuff anyway. My plugs don't look too carbon'ed either.

Rx7carl

Hook up a vacuum gauge to a manifold source and lean the idle mixture for maximum vacuum.

xman

Not 100% sure how the idle thing works. If I lean the mixture for maximum vacuume will that affect normal idle? (My vehicle's a daily driver)

Rx7carl

You do this adjustment at normal idle

diabolical1

iTrader: (3)

xman~
where do you have your idle speed set?

xman

Initially had it too high between 950-1000, but reduced it to around 800.

diabolical1

iTrader: (3)

did it do the same thing when you had it at the higher idle?

Rx7carl

You balance it. Lean it till its at max vacuum. Then lower the idle speed, then lean it again....etc....etc...

xman

In regards to your question Diabolical1, yeah, it did the same thing when my idle was set high.

Rx7Carl, I will be picking up a vacuume guage (my old one is unreliable), and trying the mixture adjust again. Not to sound stupid or anything, but I'm assuming this is all done when the engine is at normal operating temp?

xman

Managed to get a vacuume guage and adjust my mixture/idle (thanks Rx7Carl). The engine idles much better now, but still has a tendancy to stall occassionally when warming up.

My idle (with engine warm) without any accessories/lights on is around the 750-800 range, but with accessories/braking or lights on, it tends to drop to around 400. Is this the result of the voltage drain, or the result of a drop in fuel pressure, or something else? Could my fuel pump be part of the problem? I haven't replaced the fuel pump, and it's looking pretty weathered. I'm at a loss as to what to check in order to correct the problem and any help would be MUCH appreciated.

(I'm kind'a leaning toward the electrical thing as I know I have some electrical problems).