1990 tercel troubleshooting tips, my story...
rhynes
07-08-2004, 01:10 AM
1990 Toyota Tercel, welcome to my nightmare... Hopefully this post will give you some troubleshooting ideas if you own one of these beasts.
A lady friend of mine sort of inherited this car from her mom, and ever since has been a money pit. I know, i know, toyota is supposed to be a good car but this one was a short tripper all of it's life. only 80,000 original kilometers on it. can you spell carbon???
Keep in mind that my friend is financially strapped when you read this...
4 mechanics looked at this car before I tackled it, one replaced the front pipe, another replaced the fuel pump and all four wanted to (surprise, surprise) change the carburetor.
The starter was the first to go, and for those looking for it, it's tucked up behind the motor under the intake manifold... Took me 5 hours to remove it, replace the brushes and get it back in... can't begin to count the string of curses that came out of me or the pints of blood I lost on that job. Yes, the brushes are pretty much the only thing that ever goes... approx 40 bucks at the toyota dealership for the set.
The alternator was next, 2 weeks later... found a good used one luckily. It's sitting next to the starter and is not as difficult to replace. Blood loss and cursing minimal.
Next thing was the thermostat, it stuck open and the car refused to heat up. If you're looking for it, the housing sits between the tranny housing and the distributor. Do yourself a favor, spend the extra few bucks and use the fail safe thermostat, when it fails, it will fail open. The car won't heat up but you definitely won't cook the engine.
In between all this was the emission system, I refused to believe the carb was the problem... When she first got the car, she was lucky to get 200 kms to the tank of gas, extremely poor. Overall, the car ran poorly. Here is a general list of what I did to fix the issues.
- vaccuum lines: 5 were rotted, all larger (similar to size of fuel lines). Check all others. I disconnected the HAS temporarily too (high altitude sensor).
- Clean the carburetor: cheap can of carb cleaner does the trick.
- Lube the carburetor linkages: WD40 or similar does the trick.
- Ensure the TV cable isn't too loose, should be a 1/4" deflection but I found that the car would rev too high at that setting.
- Pull out and check the O2 sensor, change if necessary.
- Remove the egr valve and clean it. Check the diaphram, it should move up and down freely with little pressure from your finger. This is a good source for carbon buildup. I sprayed it inside and out with wd40 afterwards. Change the gaskets too if you can find them.
- intake cleaner: Toyota sells a product called "pre-tune", works pretty good given the price, about 8 bucks. Warm up the car, up the rpm's and spray slowly and directly into the carb til the can is empty. shut the engine off and let sit for 30 minutes. Give the car a hard run then do an oil change. the oil change is a must.
- Do a full tune-up: change the spark plugs (use good plugs like the bosch platinum, champions are terrible). Check the ohmage of the plug wires and at least clean the distributor cap and rotor contacts. Replace if necessary.
- Change the fuel filter, usually sits below the brake master cylinder.
- Keep checking the timing: I found that after replacing rotted vaccuum lines, the timing advanced again. Make sure it's dead on, or slightly retarded, think it's 3 degrees TDC. 5 degrees will give a little more oompf.
That's all I can think of right now, if there's anything else that I missed, i'll post it.
BTW, I followed the advise of my mechanic cousin... As I type the engine has a belly full of ATF fluid, not engine oil. Going to run it on this for about 500 kms and do another oil change.
The car runs so much better now, lots more power and back to 35 MPG on fuel. Can't ask for any better with a car that's 14 years old.
A lady friend of mine sort of inherited this car from her mom, and ever since has been a money pit. I know, i know, toyota is supposed to be a good car but this one was a short tripper all of it's life. only 80,000 original kilometers on it. can you spell carbon???
Keep in mind that my friend is financially strapped when you read this...
4 mechanics looked at this car before I tackled it, one replaced the front pipe, another replaced the fuel pump and all four wanted to (surprise, surprise) change the carburetor.
The starter was the first to go, and for those looking for it, it's tucked up behind the motor under the intake manifold... Took me 5 hours to remove it, replace the brushes and get it back in... can't begin to count the string of curses that came out of me or the pints of blood I lost on that job. Yes, the brushes are pretty much the only thing that ever goes... approx 40 bucks at the toyota dealership for the set.
The alternator was next, 2 weeks later... found a good used one luckily. It's sitting next to the starter and is not as difficult to replace. Blood loss and cursing minimal.
Next thing was the thermostat, it stuck open and the car refused to heat up. If you're looking for it, the housing sits between the tranny housing and the distributor. Do yourself a favor, spend the extra few bucks and use the fail safe thermostat, when it fails, it will fail open. The car won't heat up but you definitely won't cook the engine.
In between all this was the emission system, I refused to believe the carb was the problem... When she first got the car, she was lucky to get 200 kms to the tank of gas, extremely poor. Overall, the car ran poorly. Here is a general list of what I did to fix the issues.
- vaccuum lines: 5 were rotted, all larger (similar to size of fuel lines). Check all others. I disconnected the HAS temporarily too (high altitude sensor).
- Clean the carburetor: cheap can of carb cleaner does the trick.
- Lube the carburetor linkages: WD40 or similar does the trick.
- Ensure the TV cable isn't too loose, should be a 1/4" deflection but I found that the car would rev too high at that setting.
- Pull out and check the O2 sensor, change if necessary.
- Remove the egr valve and clean it. Check the diaphram, it should move up and down freely with little pressure from your finger. This is a good source for carbon buildup. I sprayed it inside and out with wd40 afterwards. Change the gaskets too if you can find them.
- intake cleaner: Toyota sells a product called "pre-tune", works pretty good given the price, about 8 bucks. Warm up the car, up the rpm's and spray slowly and directly into the carb til the can is empty. shut the engine off and let sit for 30 minutes. Give the car a hard run then do an oil change. the oil change is a must.
- Do a full tune-up: change the spark plugs (use good plugs like the bosch platinum, champions are terrible). Check the ohmage of the plug wires and at least clean the distributor cap and rotor contacts. Replace if necessary.
- Change the fuel filter, usually sits below the brake master cylinder.
- Keep checking the timing: I found that after replacing rotted vaccuum lines, the timing advanced again. Make sure it's dead on, or slightly retarded, think it's 3 degrees TDC. 5 degrees will give a little more oompf.
That's all I can think of right now, if there's anything else that I missed, i'll post it.
BTW, I followed the advise of my mechanic cousin... As I type the engine has a belly full of ATF fluid, not engine oil. Going to run it on this for about 500 kms and do another oil change.
The car runs so much better now, lots more power and back to 35 MPG on fuel. Can't ask for any better with a car that's 14 years old.
rhynes
07-18-2004, 07:36 PM
Quick update, the car was still lagging after all was said and done...
The workaround was found on another forum, and goes like this...
Locate the EBCV on the back left underside of the breather assembly.
Disconnect the electrical harness from the valve.
Trace the hose leading to the ECBV and locate the yellow "T" connector.
Remove the "T" connector and reroute the hose to remove the High altitude
sensor.
This stops the lagging.
The workaround was found on another forum, and goes like this...
Locate the EBCV on the back left underside of the breather assembly.
Disconnect the electrical harness from the valve.
Trace the hose leading to the ECBV and locate the yellow "T" connector.
Remove the "T" connector and reroute the hose to remove the High altitude
sensor.
This stops the lagging.
Doug Rodrigues
07-24-2004, 10:37 PM
You must have one of the rare Tercels. Most of them run forever without problem. I had similar problems with a GMC pickup truck a couple of year ago. It was a continuous problem every couple of weeks or so. I finally go rid of it to a GMC lover who felt that GMC could do no wrong. Last I heard, he was broke-down on a San Jose freeway.
Automotive Network, Inc., Copyright ©2025