saltandgranite

Hi guys, I just drove my '87 4x4 22r cross country to Wyoming and it went wonderfully. Around 4500 feet up in Utah (also around 18 degrees fahrenheit) I noticed, at cold start, that it started pretty slow and sounded a little "clangy". After about 20 seconds of this - without touching the gas pedal - it finally went up to fast idle and then was fine.

Now I'm at my destination in Wyoming at 7,000 feet. It's below freezing here pretty much all day. Single digits at night. I noticed after getting here that if I leave the truck for over an hour it's been hard to start. Per the instruction manual - I pump 4 times (for sub freezing temps) and then turn the key. It takes awhile to turn over and when it does it doesn't really fast idle anymore. And still sounds clangy when cold.

Prior to leaving on this trip (last week), my toyo mechanic and I set the timing, checked everything out and it ran perfect. I know the carb is set for sea level, and now I'm at 7,000 feet, but I have no idea how to re-jet and I'm just heading back to sea level in a few weeks anyway.

Is it bad for the engine to have all of these cold clangy slow starts? There's nothing in the manual about how to start at altitude. Just cold weather. Should I pump the gas pedal more than 4 times before cranking the key? Should I pump while cranking the key? Should I hold the pedal to the floor while cranking?

My top end was just rebuilt including all gaskets etc and was purring like a kitten last week.. before coming to the cold at 7,000 feet.

Help?

saltandgranite

If rejetting is what I need, then I can learn to do it... Just want to treat this engine right. But maybe slight clanginess and hesitancy to start is normal with a healthy 22r at sub-freezing temps on a mountain?

Co_94_PU

iTrader: (-1)

HAC, High altitude compensator, Assuming that is operating correctly You do nothing. Your battery could be sad and missing the warm, or you just need to go with a cold weather(lighter weight) oil.

dropzone

iTrader: (6)

What kind of.block heater and battery blanket are you using? Thermastically controlled?
Are you even using one?

saltandgranite

Hi, no block heater as my mechanic buddy said I wouldn't need it above 0. New battery, cranking fine, just starting slow. I'm running 5w30 Mobil one. Thanks so much for any suggestions, I'm in class all day and will respond to any questions this eve. I hate watching all of these fuel injected trucks firing up around me - but I wouldn't trade my 22r for anything

wyoming9

iTrader: (1)

Get a new mechanic!!! People that don`t live with this weather have no clue.

Any thing to help vehicles start better in the cold is well worth it.

I take your truck is outside??

Mobil 5w30 can`t get much lighter then that.

Is this a auto or manual??

About the first thing I did when living out there was to install a manual choke.

I think your just going to have to tough it out to school is over.

These starts are not helping how fast does your oil pressure come up??

saltandgranite

Really think I need a core heater? It's like 60 degrees out right now. And projected 20 tonight? Just saw link to high altitude compressor... Did this come standard on all trucks in '87? I'm guessing I don't have one or it's not functioning properly...

Truck parked outside and it's manual. Honestly, it's not the temp. The temp isn't that bad right now?

Co_94_PU

iTrader: (-1)

Says on federal 77-88, the test/service proceedures are on the next page. Should be simple enough to check for one, trace the vacuum line off the distributor (diagram on first page).

wyoming9

iTrader: (1)

Well if it stays that warm . Winters I remember from out there were lows from -20 to -30 Fahrenheit at night to highs of 10 to 20 with swings both ways throw in some wind that is the weather I talk about.

Have you rebuilt the carb ?/

I have not had a carbed truck in a while but mine started like crap till it was rebuilt.

Is the choke working like it should ??

You might have some other problems.

saltandgranite

Thanks for all of the help guys. So, I got a chance to run out and get the truck going tonight. It cranked up immediately - after sitting for a day. It wasn't as strong as normal startups... it didn't fast idle, but it idled on its own. It got a little faster as it got warm. And it was still pretty clanky sounding. I let it warm for about 5 minutes before driving, and it did finally kick down (even though it never got to full fast idle).

Here's where I've noticed a real difference now: When I try to start it after sitting about an hour. Anything under this and holding the gas pedal half way down starts it right up (still not as strong as a sea level start). If it sits for an hour, it doesn't start nearly as well as a full cold start. It has to crank for awhile and I can't find that sweet spot of how many times I should pump the pedal before turning the key.

Anyone know why this is?

RJR

It's likely the automatic choke. Back when i had carburated vehicles, the classic problem was starting at high altitude after a partial cool down. What happens is that the choke temperature sensor cools off and thinks the engine is cold and applies a lot of choke as though for a cold start. However, the engine really isn't that cold yet, so doesn't need all that much choke, especially at high altitude where it's short on air anyway. The result is a flooded engine that won't start. The solution is to open the hood and manually hold the choke open while someone cranks it. If you're by yourself, you can jam the choke mechanism with something to hold it open. It will usually fire right up when you do this.

Pumping the gas pedal is generally the wrong thing to do. The engine needs more air, not moe gas.

Hope this helps.

Ron