I have a 1985 truck with a 22R engine. I had the carburetor replaced a year or so ago and it has ran fine since, other than it has become hard to start when the engine is hot. Anyway I had to take it in for a smog “test only” (California), and they failed it. It passed all of the emissions numbers, but they said they could smell fuel in the engine area, the gas cap failed it’s test, and the timing was set at 40 degrees BTC!

So I bought a new gas cap, then went home to check on the other two items. I never smelled the gas (although I have smelled it before), but did verify the timing being off severely. It was off so far that I couldn’t move the distributor enough to get it even close to where it was supposed to be (0 BTC @ 950 RPM with vacuum lines at the distributor disconnected and plugged).

I removed the distributor, put the engine at TDC #1 cylinder compression, reinstalled the distributor with the rotor pointing at #1 wire, and I was able to set the timing correctly once it was running. The problem is that it runs like crap there. It sputters, and doesn’t want to accelerate, then dies, and is hard to restart (which could be a function of my previous starting problem when hot). The timing advances when I reconnect the vacuum lines, but it still runs bad.

Any thoughts or ideas? Why was it able to run well with the timing so far off, and run like crap with it set right?

 

Valve adjustment?

 

You should set your timing at 30-32 degrees total- all in at about 2000-2200 RPM. You will need a timing light that is capable of doing a total timing adjust (Sears). By using this method you will find that the timing will be around 10-12 degrees at idle. Follow the factory procedure for performing a timing adjust (disconnect vacuum hose, etc).

 

uh...no

pull the 2 vaccume lines from the distributor and plug em so there is no vaccume leak and set the timing to 0 btdc at idle

with the vaccume lines hooked up you should be at 12 btdc at idle

you might need to adjust your carb since the timing was so far off, who ever installed it might have leaned it out so much to get the idle down with timing that advanced. ( im surprised it ran that far advanced and didnt burn a valve and ping like crazy )

 

Sorry for not getting back sooner. I've never messed with the carburetor, so I am not sure what kind of adjustments I would need to do. I just downloaded the maintenance manual, but haven't checked it out yet. Is there anything specifically you are thinking of checking?

 

Finally got back to the truck...

I decided I would just put the distributor back to where it ran OK, and I would drive it somewhere to have them look at it. Funny thing is when I got it back there it wouldn't start. I rotated the distributor to the stop and it fired off but was not happy, like it really was firing 40 degrees BTC and trying to push the piston back down. So I put the engine back to 0 compression #1, and reinstalled the distributor where it was supposed to be, pointing at #1, and it started right up. Crazy.

It is still not running well, and backfires if I accelerate too fast, but at least it is drivable now. Before I could barely get down the street without it dying.

What is different? I have no idea.

I think there is something else wrong besides the timing though. I can rotate the distributor and the RPMs will go up and down, and they are closest to normal when the timing is 0 with the lines off, and slightly advanced with them on. It just has slow acceleration and backfires if I accelerate too much.

I did spray carb cleaner around the carb while it was running and didn't notice any change.

 

Have you done a compression test? Judging by the inconsistent dizzy results, your chain maybe off a tooth...

 

Well, stupid me, I guess I didn't check the timing marks in relation to the #1 piston accurately enough. I checked it more carefully, and it turns out when the piston is at TDC, the timing mark is about 24 BTDC.

Is there an easy way to align that back?

BTW, I did a compression test for good measure and they all have good compression. Just wanted to get that out of the way.

 

how are you telling the piston is at tdc with out with your timing mark being off, are you sticking something down the spark plug hole? you realized that the piston hangs out for a little bit of the rotation, unless your crank pulley has spun the outer part of the crank pulley or they key way is missing off the crank there is no way to mis allign the pistons to the tip of the crank...

so set your timing mark to tdc on the compression stroke on the #1 cylinder( remember the crank spins 2x per the cam so make sure you are on compression stroke ) and set your distributor in facing the #1 spark plug thing on tha cap. Also allign it so the bolt is middle of the travel on the distributor when you stab it in. Then start her up and go from there....

 

I stuck a small wooden dowell in the hole and watched it as I rotated the engine. Then to verify it I actually held the dowell while rotating the engine and it came out the same both times. Piston at TDC, timing mark at 24 BTDC.

I'm going to pull the pulley off and see what is going on.

 

Sorry just jumping in on this but with your main pulley at tdc open up your valve cover and check where your cam sprocket dot is at. It should be just to the left of the arrow on the rocker arm assm.. If that is way left or to the right of the arrow pull the sprocket and move it over a tooth with the main still a tdc.This will put you on a compression stroke on #1.

 

Well, it turned out that my harmonic balancer had slipped, and the timing mark was no longer accurate. I put a new one on, retimed the engine, and it runs great! Smoother that it has in a long time (apparently the balancer really does work)!