boxmaker

I've been researching this problem for a couple of weeks now and there are lots of reasons for hard cold starts with a 22re. I first thought my cold start injector wasn't working properly and I messed around with that for a while, (checked the 2 sensors etc and I set up a push button for it). This did not solve the problem though. I then discovered that the fuel pump is not turning on when the engine is cold and it's below freezing outside (about -10 C). Jumping the Fp B+ plug thing doesn't do anything and I have verified that the fuel pump works by sending direct power to it from the battery. Another thing, the engine light is not on when the key is in the on position when cold, if I put the truck in my garage and let it sit and warm up for an hour or so the engine light comes on when the key is on and it fires right up. My question is; would an old worn out key switch interrupt the flow of power to the fuel pump? If so, why would it it only do this when it's exposed to air temperatures below freezing ?

wyoming9

iTrader: (1)

Do all your other key powered items not work as well when it is cold??

The electrical part of the switch can fail I guess perhaps be effected by the cold.

I have replace many lock cylinders but never any of the electrical switches

I would explore other options first

i would think some place you have a loose connection that is effected by the cold.

it could even be solid moisture preventing the circuit to work

This can apply to the ground side of the circuit

Could be as simple as the fuse block

15 amp EFI fuse

then you have the EFI relay the circuit opening relay also the switch in the AFM

Contacts in any of these relays or the switch could be just worn enough to be effected by the cold

Could be the trucks way of telling you it wants a nice warm garage to sleep in.

scope103

-10 C? In Canada? Bah! We'll worry about you when it hits -40 C.

Use a multimeter to measure voltage to ground from B+ with key on; should be battery voltage (about 12.6, but a little less in the cold). If not, measure voltage on both sides of EFI fuse (should be battery voltage at all times) and on both sides of IGN fuse (should be battery voltage only with key-on). If you have voltage there, the problem is near or on the EFI Main relay.

Electrical problems are actually easy to diagnose; use an $8 voltmeter and work systematically.

boxmaker

It's not the ignition/key switch, I have narrowed the problem down to something in behind the driver's side kick panel because when I put a hair dryer there for 5 or 10 minutes it'll start. I've checked the ignition and engine fuses in that fuse block but not the main relay. How do I check if the main relays good ?

bbrideau

pull the relay, check for corrosion, I believe if you can find the wiring diagram for the main relay you can pull the relay and apply ground and power to two of the poles, if you hear a audible click(should feel it click too) then it is generally okay, If it is a weak click or it makes a few clicks in a row then it could be on its way out. Relays usually work or they dont work. On the bright side they shouldn't be very expensive to replace. Go to a wrecker and pull a bunch out of trucks wrecker usually only charges a dollar or two for relays.

scope103

http://personal.utulsa.edu/~nathan-b...37efimainr.pdf

RockAuto has these for $25. Is it worth $23 to you, if you eventually find out that you have a flaky relay, to replace it with a junk one? (It is to some; not to me.)

boxmaker

I'm pretty sure it's the relay, it was pretty well frozen solid. Do Rock auto ship to Canada? That gives me a good idea on price though.

Thanks for the help, I appreciate it !

wyoming9

iTrader: (1)

Solid Moisture!!

It seems you have a leak!!!

Replacing the relay will just allow another to get wet and freeze find where the water is coming from fix that as well.

Unless your just slopping that much snow in every time you get in and out.

water coming in someplace.

bbrideau

Was offering a simple solution until he can source out a new one or determines if that is the issue. I have spares kickin around just for the simple purpose of ruling out one possiblity.

Lordco is usually close in price to rock auto. just gotta talk to the right people and push the right buttons. Napa you can get lucky with sometimes too.