Topic: Weird Startup Conditions at Elevation

[Kurlee Daddee]

So I put a new motor in my truck with a performance cam. Engine had a little over 500 miles on it. Properly timed. Just did a valve adjustment and fresh oil change.

Played hookie from work on Thursday and went up snowboarding at Kirkwood for the day. Rode solo for the trip.

Got to Stockton and stopped at McDonalds for a bathroom break and breakfast. Had ran the truck around 70 mph the whole way to Stockton from San Jose. Got back in the truck and tried to start it. Turned over a bunch of times and got it to start but it felt hesitant to start and had a low idle. I had to rev it a few times to get it going. Thought if I should go back home and decided to keep going.

Got to Jackson and filled with gas. Got back in and the same thing. It didn't want to start right up. Had to rev it a few times.

Went boarding for a half day. Epic day I must say. 2 ft of fresh powder and no one there.

Got back in the truck and prayed to god it would start. Same hesitation problem but after a few rev's, it was good.

Got up to the summit on HWY 88 and pulled over with the engine running. Probably 8000 ft. or so. Unlocked the hubs out of 4WD and the I could smell the exhaust. It smelled SUPER rich.

Got back down the hill and topped off the tank in Jackson again. Truck started up normally No hesitation. Nothing.

Truck ran perfect the whole way home without a hickup.

My question. What was my truck doing? I have been running 89 octane in it since its first start up. Never had a problem until that day. Scared the crap out of me that I wasn't going to make it home. And now it runs perfect. Motor has a little under 1000 miles on it. Should I be worried of something?

[79coyotefrg]

efi or carb??
either way 500 miles isnt quite broke in yet it might get better after its broke in fully.

[Joey88RUNR]

Yea thats pretty odd, Maybe the new motor, let it break in and see what happens. My 22re seems to run better in higher elevations

[Kurlee Daddee [OP]]

efi or carb??
either way 500 miles isnt quite broke in yet it might get better after its broke in fully.

22RE. I would have assumed that the EFI would account for the elevation and the ECU would adjust accordingly. But it acted really weird. I was blaming it on the ignition system. But everything is basically new (plugs, wires, cap, rotor, etc.)

I guess I will put more miles on it and see what happens.

[Cheesemaker]

When you replaced the motor, did you check all the sensors? 
How's the O2 sensor? 
What temp was the coolant running at? 
When you shut off the motor did you let it run at idle for a few minutes before shutting it off?  I had a rig that I had to let it idle before I shut it down. 

[Kurlee Daddee [OP]]

When you replaced the motor, did you check all the sensors? 
How's the O2 sensor? 
What temp was the coolant running at? 
When you shut off the motor did you let it run at idle for a few minutes before shutting it off?  I had a rig that I had to let it idle before I shut it down. 

Yes all sensors were checked.

O2 sensor was working good. But....after the start-up incident at the McDonalds, I did get a check engine light. And I think it was caused by the O2 sensor.

Coolant was between 180 and 190 deg F. the whole trip according to my Auto Meter gauge.

No I did not run the motor at idle after I parked it. I had to piss bad!!!!

I thought of another cause for this weird idle thing. Could a PCV valve that sits loosely in the valve cover cause this too?

[junya92toy]

My 3.0 will do that too from time to time. I think its just vapor lock.

[germ]

Sounds pretty basic, but is it possible that the choke mechanism is stuck? I had a similar problem a few years ago, blasted the whole mechanism with some carb cleaner, and it went away. Watched the choke slide back 2mm, and the whole thing was fixed.

Just a thought.

Could also check the idle screw on top of the EFI, just behind the throttle body. If it's running perfect now though, this probably is not your problem.

Dead bird get sucked into the intake, and took a few miles to burn it out?

Erik

[Kurlee Daddee [OP]]

Dead bird get sucked into the intake, and took a few miles to burn it out?

Erik

HAHA! That's probably what happened. Because I drove it to work this morning and it started perfect and ran perfect. Weird  stuff happens.

About vapor lock. Doesn't that only happen when its warm outside? Or when you are beating on the car it over heats the fuel pump? I thought about both theories, but not sure if either one was the cause.

How tight is the PCV valve supposed to be in the valve cover? Mine sits in the o-ring, but is kind of loose. I can easily pull it out. Not like the old one.

[2slow4you]

might be a little different but I had the same thing happen during my trip to yellowstone last summer. Went from right around sea level to 9k feet. Truck ran like a dog, thought I was going to be stuck in Montana... So no some 22re's do not like high elevations.

[junya92toy]

HAHA! That's probably what happened. Because I drove it to work this morning and it started perfect and ran perfect. Weird  stuff happens.

About vapor lock. Doesn't that only happen when its warm outside? Or when you are beating on the car it over heats the fuel pump? I thought about both theories, but not sure if either one was the cause.

How tight is the PCV valve supposed to be in the valve cover? Mine sits in the o-ring, but is kind of loose. I can easily pull it out. Not like the old one.

No it can happen when the engine is cold too. Like if you turn it on for a min then shut if off. Its still using the cold start injector so there is excess fumes in there. I think the same thing happens after driving it at a high rpms. Its using a loy of fuel and you shut it off, excessive fumes. Cold or heat outside doesnt really matter.

[Cheesemaker]

might be a little different but I had the same thing happen during my trip to yellowstone last summer. Went from right around sea level to 9k feet. Truck ran like a dog, thought I was going to be stuck in Montana... So no some 22re's do not like high elevations.

Hope mine doesn't.  That's where I'm going in July. 

[Kurlee Daddee [OP]]

No it can happen when the engine is cold too. Like if you turn it on for a min then shut if off. Its still using the cold start injector so there is excess fumes in there. I think the same thing happens after driving it at a high rpms. Its using a loy of fuel and you shut it off, excessive fumes. Cold or heat outside doesnt really matter.

Cool. Thanks for the explanation. That's probably what happened.