Hard to start cold, hestitation under acceleration

[Esaus]

Had a recent issue after I did some tuning to my tercel 4WD with manual transmission.

I recently did some tuning. The car ran fine before the changes but has started to have some slight issues after.
I recently had the engine out to replace a clutch and a bunch of things. The carb was renovated before the summer and has ran great since then until now. The car ran great after i put in the engine and all.

Its is a standard 3A. It has a distributor with external coil. I recently changed the fuel pump to a Carter one that i got from the states.

Ive set the ignition to aprox: 11-12degrees from 5 that I had before. The car would start ok with 11 degrees. I also lowered the fast idle from the specified 3000 rpms with the vacuum hose off and the choke in full. I felt it was super annoying to have the fast idle at that rpm range. It might be 2000 rpm or something now.

I then bored out the primary jet on the carb. It has the 103 jet and when I measured it with a drillbit it had aprox a 1mm hole. A 1.1 or 1.08 wouldnt fit. 1mm was slightly loose in the hole. The closest drill I had was a 1.08. I drilled out the jet. I had the top of the carb off in the car so I didnt have the carb out or anything. I was careful not to drop anything. I only removed the parts that were connected to the top.

Now the car is harder to start when cold. In mind its starting to be colder outside now. It was 4degrees C today and the car was sluggish to start. When hot it starts ok, but if i leave it for a while it sort of behaves like my 60s buick that has fuel boiling issues. It sort of is hard to start but when I give it gas it sluggisly comes to life.

When I drive i feel that the car has more power than before. Accelerates better, runs well and goes on the highway really well. However sometimes it starts to bog or hesitate when under acceleration and moving through the gears when speeding down the highway around 80 - 100 kmh ish in forth and fifth gear under load. Then i let of the gas and after a while it wont have that issue when accelerating again.

Ive checked: Fuel level is in the middle of the glas. I tightened the carb base nuts, ive checked for any obvious vacuum leaks, I recently put in a new fuel pump, I cleaned the distributor points which were slightly oxidized but problem persists. I could feel a slightly better idle when i cleaned distrb cap. i checked the spring in the choke and set it to the middle notch.

I cant figure out whats causing it. Does the main jet affect idle at all? I believed it wouldnt change it or affect it at all. Am i wrong? Did i perhaps move something or such to cause the issue? Does the fast idle have to be at 3000?! If so i hate it

Im going to check vacuum hoses tomorrow to see if some are loose or something.

Any pointers or help is appreciated! =)

[Esaus]

When checking the diagram in the manual i see that the idle runs of the main jet line after the fuel cut solenoid. So Im guessing i need to drill out the plug for the idle mixture and change it? Any thoughts? I also noticed im missing the "stopper" gasket on the accelerator pump plunger thats ontop of the plunger. I dont know how that will affect anything. Ill replace it tomorrow i guess.

[dlb]

If you look at the rear of the carb you will see a cam with steps in it. These steps control how much throttle is automatically given at idle while the engine warms up. If things are not set correctly, you can end up starting with not enough throttle, or with the opposite problem where the engine is warmed up but it's still on one of the steps meant for when the engine is warming up. So the first thing I would do is try adjusting the fast idle back to where it was.

The next thing I would look at is adjusting the electric choke. I had an issue with it back in the summer where the car was idling lousy when cold. I found the choke wasn't setting properly when I was starting the car so I loosened the three screws and turned the electric choke dial a few degrees so it would keep the choke closed for longer. The car has started great at all temps since then. The choke is not something that was supposed to require adjusting when these cars were young, but at 40 years old it should be expected that the bimetallic spring in there has gotten a little tired. The electric chokes on Weber carbs also often require seasonal adjustments so it makes sense to me that the electric chokes on stock Tercel carbs might also need that sometimes.

I think that the chokes on US tercels are riveted in place, hopefully your Euro tercel is not like that. Canadian ones are screwed down so it's nice that we don't have to drill rivets out. If yours is screwed on though, be careful not to strip the head of the screw. Those tiny old things probably haven't been touched since the car was made so they can be difficult to break free initially.

Good luck!

[Paul]

Just a couple basic things... I've have best luck punching the throttle once, then cranking it with my foot off the gas. Pop the aircleaner lid when it's cold, then press the throttle once to set the choke and see its position. Even if it dies, I try to restart with my foot out of it.
The hesitation might be your pump shot. You should get delivery soon as you move the throttle.

[Esaus]

Thanks for the tips. I managed to fix the issue.

My thought was since it mostly started after i opened the carb as i set the lid upside down and the hesitation mostly came during heavy load that it was a fuel starvation issue. I suspected that I dislodged debris in the small filter before the needle seat.
I checked it and it was full of debris and junk. Mostly oxidation and rust. I cleaned out the area and scraped the metal inletpipe and everything with a screwdriver and paint gun brushes. I also checked the acc pump and inserted the extra gasket i had forgotten. I managed to break the pump leather so i replaced it with a old one that was in like new condition. I also set the float since it looked too low.

I then rechecked all vacuum hoses with no issues there. I also noticed before when i removed a sparkplugwire i didnt get shocked that much so i cleaned the breaker Points. I later got a shock that was how i thought it would be hehe.

I then tried resetting the idle. I wasnt able to get a idle below 800rpms. Turns out i put in the acc cable too tight after the engine out. I loosened it and was able to fix that. Ill also look for a new acc cable spring to pull it tighter. The spring seemed on the weaker side of things.

I also had a slight miss so i checked the workshop manual and redid the fuel mixture procedure and set it as lean as i could with 650rpm. Before it would almost die when i set it to 650. The car idles better now and runs smoother. I also get less smoke out the tailpipe than before. I guess its been too rich this whole time.

I later started the car when cold and it fired right up! Was alert and no stumble. I guess the debris had starved it of fuel + all the other small things added up. It feels like a different car almost.

The whole thing took about 3 hours or so. I had to recheck and think and check the manual several times. It was very frustrating to figure it out. Im glad its done!!

[Esaus]

I can add a point after ive had the car for a while. I've had similar issues since i did the initial fix. it has always been a fuel starvation issue all those times. Mostly it has been the fuel filter ive added directly after the fuel tank. Ive had issues with rusty tanks since the restoration. ive replaced the whole tank and i had to sandblast the replacement tank and do alot of welding on it. Due to this it had alot of sand blasting media in the tank so i had to add a filter directly after the tank. Ive had it clog up several times when ive ran the tank empty and refilled it. The sand was hard to get out of the tank!