Engine Type and Fuel Delivery Questions

[deejay1272]

I noticed that my '85 Tercel engine says "3A-S" on the side of the block. I've done some searching around and I'm not able to find anything on this engine type. Is this a misunderstanding on my behalf? I also noticed that there is a sticker on the firewall that says 3A-C, so perhaps that's the more official engine type description. Any thoughts on what engine type I really have?

Second topic - I have a difficult time starting my Tercel after it cools down (difficult start, then rough idle until it warms up to normal operating temperature). I gather, from reading many posts, that I should probably focus on possible vacuum leaks first, then attack the carb. I'm curious to hear further insight from the members of this forum - is this a sensible approach for my dilemma?

Thanks,
Dan

[Petros]

The 3A-S might be an imported crate engine from Japan, and the original 3A-C was replaced with the used imported engine, hence the mismatch in the labels. I have never heard of a 3AS installed in a North American Tercel.

A vac leak can cause the hard start, other symptom would be rough idle, or fast idle after warm up. It could also be the auto choke. Easy check, after the engine is cold, remove the air cleaner cover and watch the choke plate when you advance the throttle and release it. The choke should snap shut. If not you need to service the autochoke.

Good luck.

[deejay1272]

Here's a bit more about my strange engine type question that I posed a while ago. The information under the hood of my Tercel says that the engine is a 3A-C, but in clear lettering on the side of the head is a sticker that says 3A-S. I can't find anything about the 3A-S engine online!

I'm guessing that someone put a new engine it this vehicle. Hopefully one with less mileage than my odometer shows!! I suppose I could compare serial numbers to answer this question once and for all. Next weekend, I suppose...

[tercel4wdrules]

Your engine is the JDM 3A-SCV, it's a common 3A variant imported to replace the 3A/3AC. These engines have a vacuum dashpot at the very back of the head (firewall). I hope this provides some insight that you are seeking. There are several members on the forums that have this engine in their T4WD's.

[deejay1272]

Thanks for the clarification! Given the fact that the info panel on the firewall says that there's a 3A-C engine in this vehicle, do you think that the original engine was swapped out?

(man, I wish I had some more history on this car!)

Thanks!

[blade]

ya the motor would have been changed because if im correct no tercel came with the 3a-S i have two of those motors in my shop and if every thing on the motor works that is one great motor.

[Highlander]

Deejay- I have (well OK, my wife has) one of these engines in her T4WD. Good enigne, I just figured out how to hook up the dashpot- there's a thread about the 3A-SCV in the repair questions forum. We get 32-35mpg in mixed driving with it. the tuneup specs SB the same as the 3AC.

[deejay1272]

I have a difficult time starting my Tercel after it cools down (difficult start, then rough idle until it warms up to normal operating temperature). I gather, from reading many posts, that I should probably focus on possible vacuum leaks first, then attack the carb. I'm curious to hear further insight from the members of this forum - is this a sensible approach for my dilemma?

Update: the cause of my difficult starting condition was a result of an improperly closing choke plate. Liberally squirting carb cleaner as I moved the choke plate back and forth fixed the problem. Next problem was associated with the odd idle characteristics that I was experiencing. The car would "hunt" for the proper idle speed. In order to fix this, I carefully sprayed carb cleaner on the connections to first rule out the possibility of a vacuum leak (very, very common problem - especially with T4WDs with OEM carbs installed). After this possibility was eliminated, I moved to to the fuel delivery system. After much searching I found that my poor idling problems were associated with the fact that the butterfly valve at the base of the carb wasn't closing properly. The extra .001" required to close it off completely wasn't happening with the stock spring so I took Takza's advice and mounted a smaller diameter spring inside of the stock spring. Now the butterfly valve closes beautifully and I achieve the ~850 RPM idle that I always dreamed of. Beauty! Only problem - I have to put several pounds of pressure on the goddamn gas pedal to get the car to move! It makes me a slower driver so it probably saves me a few MPGs in the end.

Another issue contributing to the poor idle condition was associated with the ignition timing. When I bought my Tercel it was reading about +2 degrees but I've since retarded (heh) the timing down to ~13 deg BTDC. This has not only improved my idle situation, but also the low power condition I was seeing when I bought the vehicle.

Looking forward: A few things that I still plan to do:

• New Timing Belt
  Flush radiator
  Replace rear diff gear oil
  Replace transmission fluid (I don't want to lose my transmission like so many other peeps on this forum)
  Replace passenger side rack and pinion boot, Install CD player and speakers
  Sew new shifter boots (Thanks, Tom!)
  Somehow find a way to replace the carpet (any help would be appreciated)
  Replace the severely cracked windscreen
  Replace or simply clean the seats (one day)
  Perform a complete overhaul of the suspension (special attention paid to the shocks - I have a bouncy ride at the moment)
  Install (you guessed it) a Weber carburetor and fuel pump to supply ~2.5-3 PSI

This should be fun times indeed.

[takza]

Looking forward: A few things that I still plan to do:

• New Timing Belt
  
  Flush radiator < try the Prestone flush kit? just don't leave the T in the heater line...they can break
  
  Replace rear diff gear oil < real easy to do
  
  Replace transmission fluid (I don't want to lose my transmission like so many other peeps on this forum) < probably a high priority item...use the air powered trans filler jug. This device is based on alien technology I received when taken up into a saucer...so you know it works
  
  Replace passenger side rack and pinion boot, Install CD player and speakers
  Sew new shifter boots (Thanks, Tom!)
  Somehow find a way to replace the carpet (any help would be appreciated)
  Replace the severely cracked windscreen
  Replace or simply clean the seats (one day)
  
  Perform a complete overhaul of the suspension (special attention paid to the shocks - I have a bouncy ride at the moment) < one rubber donut per spring will help with the sloppy ride...handle better and brake better.
  
  Install (you guessed it) a Weber carburetor and fuel pump to supply ~2.5-3 PSI

This should be fun times indeed.

[red91sit]

• New Timing Belt
  Flush radiator
  Replace rear diff gear oil
  Replace transmission fluid (I don't want to lose my transmission like so many other peeps on this forum)
  Replace passenger side rack and pinion boot, Install CD player and speakers
  Sew new shifter boots (Thanks, Tom!)
  Somehow find a way to replace the carpet (any help would be appreciated)
  Replace the severely cracked windscreen
  Replace or simply clean the seats (one day)
  Perform a complete overhaul of the suspension (special attention paid to the shocks - I have a bouncy ride at the moment)
  Install (you guessed it) a Weber carburetor and fuel pump to supply ~2.5-3 PSI

This should be fun times indeed.

You can get new carpet online in a variety of colors. If it is like most cars, you just have to remove the seats and plastics around the perimeter of the vehicle and gear center area. Then the carpet should pop right out.