fire5

I live in Canada and drive an 86 22re pickup. When temps hit well below 0* (-20 and colder *C, or -4*F), I turn the key, the CEL does not light up, the engine cranks, and will not start. Fortunately I'm usually at end of work (so it's been sitting approx. 10 hrs with block heater plugged in, which works by the way) shift and buddies help me push it inside.
Now here's what baffles me. (This is the 4th winter I've owned it and happens sporadically over the cold months.)
Once inside in the warm, I know from experience now to wait approx. 10 mins, and it fires right up normally, with the CEL illuminated with the other dash lights. Last winter I unhooked a fuel line in the engine compartment to see if I had pressure and had none. Would wiring on top of fuel pump be faulty and affected only by cold, cold temps? Or is there a sensor acting up?
Any insights into what to replace or fix would be great. Has anyone ever had a similar problem?

4runnerx3

Have you checked the water temp sensor when its that cold? I would do a continuity test on it.

fire5

I'll do that tomorrow as I'm at work now. Are you meaning test it with an ohmeter?
Thankyou for the input.

thook

Yeah....that ECT thing.

The temp sensor could be part of a running problem, but the starting problem would be the cold start injector time switch. That might also explain the lack of fuel in the line. But, the lack of a CEL means intermittent power to the ECU. Which could be a faulty relay or fuse.

Try this....get a simple two way on/off toggle switch. Hook a wire from battery ground to the off position of the toggle. Take another wire and hook it to the neg side of the cold start time switch connector...not to the switch, the connector ......and the other end to the on position of the toggle. Turn the toggle switch to on and try and start it.

EDIT: since you're at work, if you need to run this expirament, you can blow off the toggle and directly hook the wire from neg battery side to the neg. side of the time switch connector and try to start it.

fire5

Thankyou VERY much for the knowledge. I decided to leave the truck at home in warm garage (treat it nice for the night as it's going down to -40*C...yikes!), so I'll be able to run around tomorrow.
I can't wait to try that technique, thook. One question though - how do I determine which side is neg. on the switch?

fire5

Yota4, I had originally thought the AFM was the culprit. It is dry, no moisture or ice.
The first time it happened this year, I lifted off the air filter cover that houses the AFM, and had a friend make sure the flap was open. We were inside letting the truck warm up. Nothing. Same symptoms. Let it sit for a few minutes, went back, turned the key and CEL with all other normal dash lights came on and the truck fired up perfect.
This has been stumping me since I've owned it.

4runnerchevy

I ran my 86 with a pushbutton cold start for 7 years, no prob. Tap it a few as you start and your on the road. The cold start inj. is pressure all the time from the rail, so just hook 12 v to it and go. Dont leave it too long, it will burn up the injector. I no longer have issues!

fire5

Sorry Chevy, but could you detail out your explanation for me? Particularly your voltage hook-up. Did you run a wire from the neg. battery post to...what part of the injector?(Neg. side?)
And do you mean you un-hooked the wire or else it would burn out the injector? I hate making you guys work.

4runnerchevy

I hooked from the neg side of the battery, to the neg side of the cold start injector. I then hooked the positive through a momentary switch. When you start it just tap the momentary switch a couple times while cranking. Don't hold it too long because it might burn out the injector, as well as flood the chamber.

This is not the right way to do things, but it works.

thook

Off hand I'm not sure which side is which. But, you can take a volt meter and determine which side of the connector has voltage with the key on. Not only that, there's only two terminals. So, one side will work and the other won't. Pretty simple, it is.

fire5

Gotcha Chevy. I understand now. I'm going to get the necessary items today to try thooks process as to avoid a burn out issue with the injectors as you mentioned Chevy.
I'm excited to update with positive news regarding this bothersome glitch.

bigt

im having the same issue and i cant get to my cold start time thermo switch because of ac and rad lines.. i could get to it in my parts truck because it was a base model... and i had some stuff off the engine.... so i have a good time switch but it might be easier to hotwire like your dudes are talking...

thook

Note to whomever shall bypass the time switch...

Make sure you have some way to disconnect/break/deactivate it (time switch circuit) once the vehicle is running. You don't need it sending a constant signal to the ECM once the engine is warm enough.

bigt

you mean like make sure you put a switch in the line and hot just a a wire thats hooked up all the time??? yeah some days i might be slow but im not that slow... but good advice if anyone reads this thread.. since the cold start injector was easy to get at i put a good working one from my parts truck in and if when its good i still acts up ill look into hot wireing

thook

Yep, a toggle switch at the dash with lines run to and fro is the way I did it. So, when the motor's cold I just reach down, pull the toggle (to create the necessary ground connection), start, and push it back once it's running.

aviator

-40*C!!! Holy heck fire 5 just where in the great white north are you anyway?...

fire5

"Winter"peg...er...Winnipeg. That was with windchill overnight. Yeah, brutal. I'm originally from the Ontario banana-belt though.
I've picked up the items I need but have been lazy to hook everything up. Tonight, hopefully. I've been careful when out and about so not to be stuck somewhere.
I'm back on nights this Friday, so I'll have it done by then, leave it overnight and cross my fingers and hope it works. Putting all my faith in this, Thook! Ha.

fire5

Should I just get off my wallet and replace this switch?

bigt

i had a hard time getting mt mine because of ac lines.. on my parts truck with no ac is was easier to get at

thook

It will work.....if the cold start time switch is your problem. Replace the switch, if you have the dough. Otherwise, you'll be good to go for a while and can save the money for something else. That's what I did. Eventually I'll replace it, though. It just hasn't been critical.