Cold start is a bitch

[Guest OB6D]

I'm puzzling on this one:

The damn thing doesn't want to start when it's cold. Once warmed up it's fine. Now i got this idea it's running a little rich when starting cold, because when i pull the hose from the air bypass and it gets more air then measured, which leans the mixture, it will start, but only then. And then it runs like shit for half a minute and i keep the throttle partly open. Then after that half minute i can rev it, but it won't idle properly. Then as it gets warmer, it will idle again. And then the warmer it gets the smoother the idle.

When once it's idling i pull the plug from the watertemperature sensor, it stalls right away.

And i was wondering, the thermo time switch is this brown plug right. And the temperature the blue one. Cuz i know i've been f*ckin' this up, expecting the blue one to be time switch, cuz it's blue like the cold start injector. Which it isn't?

So if i've switched them [put new plugs on em, black and white, didn't have anything else] then i would have put a 12V+ on the temp sensor. So now i'm guessing i killed it.

I never had a problem cold starting, till at some point, where i don't know what happened. But i know i've never used the cold start injector and that was never a problem. Till i decided i wanted it to work again.

Also i gotta admit i adjusted everything adjustable.

But like i said, once warm, it's fine.

[V-M]

Brown one is thermo switch I have buzzling those also and didn't broke anything.

V-M

[Guest OB6D]

Yup, the brown big on is the switch. Also i've tested the temp sensor, the blue one. It seems okay to me. I got a spare, put that to it in the plug and then held my lighter to it while it was running, didn't seem to make much diff.

I also seem to have no fast idle, so i put my spare extra air valve in place, still no fast idle.

Tomorrow i'll check the throttle switches once more. Can't figure anything else.

[august]

if you can focus on the thermo time switch / cold start injector i'd start there. if your sure that's working i'm really not sure. do you have another AFM you could try for the hell of it (i've see a bad AFM make some weird stuff happen) :S

[Guest OB6D]

No, honestly i disconnected the thermo time thingy. Because i felt it was running rich, since it only wanted to start with the hose pulled from the extra air bypass valve. So i figured it didn't need more fuel.

But then again, once it's running and the lambda sensor has warmed, my leds indicate a lean mixture...

This morning it did fire right up, but then after about 10 seconds it stalled. Then i had to do the pull the hose routine again...

[Guest OB6D]

I just don't get it. It doesn't fast idle either.

I pull the hose, between the extra air valve and the intake "horn". I start it, then i gotta keep revving it, else it stalls. Then after about a minute i exit the car and jump for that hose and reconnect it. Then it runs a poor idle at i guess about 500 rpm. Then i just wait for it to warm and i gets better 'n better.

Then i drove around a bit. And then this problem i've been having before reappeared. It started to cut off at idle. I'm guessing cuz it was now doing 1200 rpm idle. I've had this cut off problem before, i thought i'd fixed it with readjusting the throttle valve.

Prior to this, time ago, when it did this cut off thing, i used to plug the bypassed air so it would get none and then it would idle smoothly.

Now after readjusting things, if i squeeze that bypass hose, the engine stops.

I wish i had spare modulators 'n stuff, like AFM's, but i don't...

Also when i'm driving and i keep my foot still and speed steady. I can see my mixture lean out on my led box. Then with a bit more throttle and more speed, it restores to normal again.

Oh yeah, i can also add. I've connected a push button to my cold start injector. So i can inject more fuel whenever i please. And at cold starting, pushing this don't help at all. So i don't. Then again, with this hose pulled i can see my mixture go from rrrrrrrrich to more like stoichio value where it ignites and starts...

And then right after startup mixture appears to be lean.

So that'd be where the thermo time thingy comes into play. Didn't it get the + from the safety relais...

And then it's + at cranking only i believe...

I gotta figure this out, a car that don't start in the morning is useless.

[bill]

I had a cold start problem on my old '88tw.

What a pain. I'm not kidding when I say that I used to go out when it was zero degrees and place my trusty Coleman camp stove under the engine for about 40 minutes or so. Outside. I had to be careful where I put the stove (there's an obvious place). It actually worked, but I am always hesitant to recommend it, for obvious reasons.

I remember after trying to troubleshoot, and being so desperate that I started throwing money at the problem. I recall trying a new thermo-time switch, and another cold start injector, all to no avail (I could have had a few really nice bottles of Scotch instead).

I ended up fixing it, or should I say, it fixed itself, when I put the engine into another car. The only thing that I can guess what might have done the trick is that one of the harness connectors needed cleaning (I took the time to clean each and every connection when I did the swap).

That's where I would start if I were you.

You will need some little files and such. Can of spray cleaner. And time, of course. Even invest in some of that expensive anti-corrosion paste. It's cheaper than getting stuck somewhere. (Nevermind the "What are we going to do now?" from the old lady). Plus you never know what problems you might avert down the road.

I've always had to make my own little files on my bench grinder to clean the female slots. Does anybody make them, as I haven't seen them for sale anywhere. Maybe I am looking in the wrong place..

Good luck,

Bill

[Guest OB6D]

Thanks,

I've bolted an other head on, might very well be something aint plugged in right...

I'll check that.