WYrider

I have an 87 pickup with a 22R. I just put the engine in. It will start up just fine but it surges real bad, most of the time it wont die. But it only does this when its cold. When it warms up it runs just fine. But it smokes black real bad when cold/idle and is dumping fuel out the exhaust. Went through the carb with someone that knows what he is doing. also put another carb on it. no change.

Any ideas?

ttrmike

Check the AAP (Auxiliary Accelerator Pump) diaphragm.

alltracman78

Doubt that's it if he's had the same problem with 2 different carbs.
Not impossible though.

Just some random thoughts.

Generally vacuum leaks will cause you to run lean, but it's possible you've got one [especially with a "new" engine].
Have you checked your spark when it's cold? Are you misfiring when cold [misfire may be causing the excess fuel out the tailpipe]?
Hows the cold compression? If you're not getting enough compression that will also contribute to a misfire.
Does it help if you rev it? Or does it still run like crap?
Possibly a problem with the factory cold start system [your carb is controlled by an ECU].
Choke is working?

ttrmike

This has the tell tale signs of a broken/ruptured AAP. The super rich starts and black smoke until the engine is up to temperature to stop vacuum to the valve. When I bough my Auto-Line rebuilt carb the AAP diaphragm was already broken (though I didn't know it at the time since i had a host of other problems to deal with first.)

The carb on these truck is not controlled by an ECU. The electric choke, and fuel cut solenoid are triggered by the key. The ECU that your thinking about is actually just the emissions control computer, and triggers the vacuum switching valves for the evap canisters, and the vacuum valve for the deceleration fuel cut system.

OP, i would suggest downloading the 1985 and 1988 FSM for these trucks from here: http://www.ncttora.com/fsm/

alltracman78

You're right.
I assumed all the trucks were the same. Only the Cali emissions has a fuel feedback system, Federal emissions doesn't.
I also assumed it also controlled the cold start system, but it doesn't, sorry for the misinformation.

It seems unlikely that 2 different carburetors would have the exact same problem, but it's not impossible [as I said in my first post ].

There should be a pretty easy way to see if that's the problem.
Bypass the TVSV. If it stays running rich once it's warmed up, the AAP probably the problem.
If not, you'll need to keep looking.
Hopefully it's that, so you won't have to spend lots of time searching.

alltracman78

You're right.
I assumed all the trucks were the same. Only the Cali emissions has a fuel feedback system, Federal emissions doesn't.
I also assumed it also controlled the cold start system, but it doesn't, sorry for the misinformation.

It seems unlikely that 2 different carburetors would have the exact same problem, but it's not impossible [as I said in my first post ].

There should be a pretty easy way to see if that's the problem.
Bypass the TVSV. If it stays running rich once it's warmed up, the AAP probably the problem.
If not, you'll need to keep looking.
Hopefully it's that, so you won't have to spend lots of time searching.

ttrmike

It should have put that in my last post. An easy way to check the AAP is to pull the vacuum line going to it and check for gasoline in the line. If there is, you can bypass the system by placing a BB in the vacuum line.

If it does turn out to be not directly carb related, check the condition of all the vacuum lines and there routing. Vacuum leaks can pose some pretty perplexing situations.

drew303

There are so many variations of the 22r it's rediculous. I personally own an 87 non cali and cali versions... similar but different. Besides that there are other variants when u go back in age with the carbs and the engines themselves.

Anyway, things I'd look for are issues with the choke, the electric choke is controlled by a BVSV valve in the plenum. If the hoses to this arent hooked in correct youre choke wont work at all. Thats more of an FYI..the diaphram (sorry im not privy on the terms of the diaphrams right now, its been a few years since ive rebuilt one of these)... controls whether the Electronic choke turns on or not.

Are your distributor vac advance hoses hooked up? ... You'll get a very rough idle when starting cold without them hooked up.. sounds obvious but its an easy thing to forget to hook back up after doing timing.

A slew of other vac related (not vac leaks) but just hoses hooked to the wrong components can cause a number of odd behaviors with the engine.

Just recently I did a top end on a 22r and had the choke hoses simply mixed up, no choke, ok fixed that.. more issues..two more hoses that go near each other were simply swapped which caused some very very very unusual behavior at certain RPMs...

Also, you may just need to drill out the idle mixture plug and adjust it. 3.5 turns out is factory but every older 22r carb ive seen has needed adjusting