carb85

Hey guys,

just recently I renewed my cylinder head gasket and my timing belt on my carburetted 22R.
Now I put everything together and started the engine ... fortunately it started after three weeks of works.

Only one thing: In idle the RPMs are going up and down between 1000-1400 RPMS...the engine is bucking. Timing is set to 5°.

When I am just rolling on a highway downhill (without any throttle from the gas pedal) the engine is bucking as well. As soon as I accelerate again the bucking is getting better.

What could it be? Distributor? Spark plugs (I took the old ones)? Vacuum leak? What should I check? Is anyone here who had the same problem?

Sorry for the questions ... but it is the first time I repaired something serious on a car and am a bit stuck.

Thanks for your answers in advance :-)

carb85

Here I got two pictures of my distributor...cleaned it a bit with sandpaper because there was a lot of red dust on it (yaeh ... welcome to Australia). The bucking did not get better after it. Does it look worn to you?

1989toy4wd

It doesnt look that bad...did you replace the spark plugs, wires, or anything, if not, it may just be time for a tune up

flyingbrass

Timing on the carbed motors is supposed to be set at 0 with vacuum hoses disconnected from the distributor and plugged. That's at an idle speed of 950 RPM max. When you reconnect the vaccum lines it should read somewhere around 12 BTDC.

I'd get it timed correctly and then go from there.

abecedarian

As mentioned, timing should be set with the hoses to the distributor both disconnected and plugged... be sure you plug the engine side of the hoses.

With regards to the idle speed and actual timing, you should defer to the decal(s) under the hood. Otherwise, I find it difficult to believe a 22r would have a spec'd idle of more than 800 rpm and initial advance of more than 8 BTDC. Call the dealer with your VIN if you can't find what you're looking for in a book.

carb85

Ouch ... set the timing WITHOUT vacuum hoses? Damn ... I set up the timing with them. One question: Do I really have to disconnect ALL hoses from the carburettor or does anyone has to stay connected?

Nevertheless I just ordered (10 minutes ago) a carburettor rebuild-kit. A friend told me he had the same symptoms with his Volkswagen T2 kombi and solved it by rebuilding it.

BTW: New spark plugs were not helpful - but now I got a bit more torque when accelerating :-)

flyingbrass

Disconnect only the hoses from the vacuum advance gizmos on the distributor. Two, IIRC. Pull them off at the distributor and plug their ends. Check and adjust timing to 0. Take plugs out of hoses and reconnect them. Check timing again. It should be somewhere around 12 BTDC. The pulley doesn't have a 12 mark, but you can eyeball it. That's what my FSM says. It's also what my truck did and had better do again when I get it back together.

950 RPM max is what the FSM says. Seems high to me, but that's max. 800ish would be better. You want it low enough that the advance isn't kicking in. I presume 950ish is where that happens.

Of course, go by hood decals if you still have them.

dhall50

This left me kind of confused. I have a weber carb and when it is tuned it doesnt pull vacume at idle. So if i set my distributor to 0 or 5* it stays at that setting even with the vac lines hooked back up at idle. Does this mean I should put it at 12* while the vacs and everthing is hooked up?

82blueyota

A bad manual fuel pump can cause bucking it may not show a leak mine didnt the first time it went out.

xxxtreme22r

dhall mines the same way, it's normal.

dhall50

So what do you keep yours at extreme?

xxxtreme22r

0 degress. without the vac line.

Anthony Wright

Re. bucking car: My '78 Celica was giving me fits. It was the carb but I didn't know what. One guy said replace the AAP diaphram and I did, but the problem was the float! Here's how I knew what it was. I'd take the carb apart in the warm weather we get here in Calif. and put it back together after an hour or so. It'd run nicely for a few miles and go back to running RICH. I'd do it again and the same thing would happen. Then it ocurred to me: The float, being made of some sort of semi-porous plastic, would dry out and work the way it's supposed to by cutting off the fuel until it'd absorb gasoline again and sink and it'd run rough again. I replaced the float - and problem solved. It was the original float and the new one was available from an online dealer in Texas. Tony Wright '78 Celica daliy driver.