Terrible fuel mileage and new car to me

[Liveaction]

Well so I am new to this whole forum thing but it seems as though y'all are a very helpful group of people. I just recently bought a 1981 Toyota tercel corolla and i bought it without to much research, well come to find out it seems to be almost impossible to get parts for not to mention a FSM to use with it. I know this is a four wheel drive forum and mine is 2 wd but i would greatly appreciate any help on where to find stuff for these vehicles. I currently am only getting like 19 mpg and that sucks as i purchased it to commute back and forth to work in. Thanks in advance for any guidance also i did change plugs,wires, cap and rotor, and fixed the obvious vacuum leaks and the day i bought it i had the timing belt and water pump changed. Thanks again

[TURTCEL]

Welcome to the crew Liveaction.

Eventhough you only have 2wd Terc have no fear, you will be helped out. I am not really familiar with your year of Terc but there are tons of comonalities between older carbureted rigs...basic stuff.

A really helpful addition to you would be that FSM for your rig, sounds hard to locate but I am sure it is out there.

Did you check the timing after your tune up parts were installed, correct plug gap too? The carb has some adjustments on it that could also be a little off as well. Vacuum leaks on these cars are a notorious factor to runnability. Make sure all vacuum hoses go to their correct location and that the carb itself is not leaking vacuum from a gasket or seal area too.

I am sure you will be getting a lot more advice from members soon. Keep checking your post.

Also, did you change your filters on the car...can be a huge factor. Air, fuel, oil, and pcv valves should all be changed.

Good luck.

Peace

[TURTCEL]

I just checked Amazon for you and they have the Bentley Service manual for you car starting at $2.61 + shipping. There are 10 starting at that price. Not so hard to ge a manual for you rig. Check out Amazon.

Peace

[Mattel]

Hi Turtcel, I just removed your double post. If you are wondering where it went.. cheers.

[Liveaction]

Thanks for the quick replies I will go on amazon today and as for the timing I noticed that the distributor is all the way turned to the left and cant be turned any more so i was assuming the guy that put the timing belt on may have it one tooth off. Are there marks on the gears for the timing belt and if so should they be at say 12 and 6 position. Also was wandering about the vacuum lines to the vacuum advance as I have three and most posts talk about two that i have seen. Once again i have zero forum experience. I am a mechanic for a living so mechanical inclination is not a problem of course not cars but helicopters are what i am used to thanks again

[dlb]

hi liveaction. it sounds like you have a first generation tercel. the only commonalities between it and the 4wd wagon are the engine, carb, and emission stuff, but luckily, that is most likely where your problem is. even more luckily, you can use the FSM available here for that carb and engine. here's the link.

https://tercel4wd.com/forums/viewtopic.php?f=2&t=8103

lots of things to check for poor mileage. i'll list them to try to make it as clear as possible and start with the most basic.

1) tire inflation. make sure tires are at 35 PSI.
2) extra weight. don't bring your cast iron weight set or anything else heavy with you everywhere.
3) ignition timing. use a timing light and set your timing to 10* BTDC for a bit better mileage and performance. stock setting is 5* BTDC. the timing marks are on the lower timing belt cover, just above the crank pulley. follow the procedure in the FSM.
4) tune up. check your dizzy cap, rotor, spark plugs, spark plug leads, and replace as necessary.
5) vacuum leaks. remove the air filter housing and check the mess of black vacuum hoses. make sure none are cracked, unattached, or routed improperly. there should be a vacuum diagram on the underside of the hood which you can follow to make sure they are hooked up correctly.
6) hidden vacuum leaks. check the diaphragms on the vac advance unit (on the bottom of the dizzy) by connecting a clean hose to each port and sucking, then plugging the hose end with your tongue. they should hold vacuum. if they don't and you are able to suck air through them, remove the hose and plug all involved ports or replace the vac advance unit. there are other hidden vac leaks but this is the most common that i find on tercels.
7) AAP. you will find this in the emission section of the FSM. it is a diaphragm on the front of the carb that makes the carb run rich while the engine warms up. if the diaphragm is ruptured though, it will cause the carb to run rich all of the time. this is a common source of poor mileage and/or poor running.
8 - automatic choke. check to make sure the choke valve opens fully when the car is warmed up. sometimes (usually after sitting), the choke can get stuck and cause rich running throughout all heat ranges. if it is stuck, just tap it free and lube the pivot points and linkage with WD-40 or something similar.

those are the first things that come to mind for me. work through them and see what you find. as turtcel mentioned, i'm sure more peeps will chime in with more advice shortly.

welcome, and good luck.

[Petros]

Welcome to the list,

you also might double check the cam timing was done properly, just pull the upper timing belt cover, set crank at TDC and verify the hole in the sproket lines up with the marker on the front of the head. Than check your spark timing, not unusual for it to be installed a tooth off and than you can not get proper timing.

Than as noted above, vac leaks and proper vac line routing, AAP, etc. Also, check all the brakes are not locked up: jack the front of the car up, pump brakes and than go rotate tires, one caliper could be hanging up. If you find nothing wrong, try doing a compression check on the engine and see what you get.

That first gen Tercel is very light and should get about 36 plug mpg if everything is running properly. Should be easy to find, these early cars are rather simple despite the maze of vac lines (not so hard to understand once you know how all the systems work). Good luck.

[dlb]

Also, check all the brakes are not locked up: jack the front of the car up, pump brakes and than go rotate tires, one caliper could be hanging up.

that's the one i couldn't remember! glad someone else did. crucial to check. other signs of a hanging up brake will be that awful burning brake smell when driving, heat emanating from a wheel, or even smoke coming from a wheel well. speaking of which—i just sold our VW westfalia and as soon as the new owner bought it, she drove it to a mechanic for some work she wanted done. i followed her so i could drive her back to her car at my place. when we got to the shop, i could smell something burning. she immediately looked at me and asked if it was burning oil, as if i had ripped her off. i said it smelled like brakes to me, but both the front brakes seemed fine. then i looked back and both the back wheels were smoking like crazy! i asked her if she had driven with the park brake on, and yep, she had. then the mechanic came out and ragged on her for it a bit. she was pretty sheepish after that. thank god that the van was already paid for!

[Liveaction]

Thanks again for the replies i will start going one step at a time through this thing with y'alls advice. Also just curious is the #1 cyl clossest to front or rear of car, and the dizzy is turned all the way to left counter clockwise with no room for adjustment does that mean maybe its retarded all the way or advanced all the way? Thanks again

[dlb]

#1 cylinder is closest to the front of the car. if the dizzy is as far as it can go counter clockwise, it is as retarded as it can go. remember to disconnect and plug the manifold vac advance hose when checking/setting the timing though, and hooking it back up afterward.

[Liveaction]

Well I have not checked the fuel economy yet but the cam timing was off one tooth at timing belt. So that should definitely help.not sure how much better fuel mileage will get but hope alot. Thanks for all the suggestions and I will let y'all know how much better it gets.

[TURTCEL]

If the belt was off by a tooth then setting it correcty should greatly improve your fuel economy. If the vehicle is firing at the incorrect time then fuel is not burning effiently and the car will prob be running pretty crappy. You can adjust the dizzy to compensate for a tooth off belt so make sure you recheck your dizzy after the belt is reset correctly.

Peace

[Liveaction]

Well the timing belt off a tooth did nothing but give me false hope for good fuel economy. Did not increase at all. But I did check today and timing was right at TDC so i adjusted to 10 to the left of TDC which i believe to be before TDC. But i did check the vacuum advance on dizzy and did the whole suck on the line thing and i dont have suction on any of the three ports. So i will need to find one of those. Just curious to know if it will indeed increase my fuel mileage and if so by approximately howmuch. If not greatly i will soon have a very clean 1981 tercel with not all that great fuel economy for sale. Thanks again for the help

[TURTCEL]

Don't give up yet Liveaction. That little car will be a good car to you. This is the time when you are just getting to know her.

How do you know that you are not getting better fuel economy? have you mileage checked it? There will definitely be an increase in fuel economy with timing belt being correct now...how much exactly is still a who knows question. The timing must also be set correctly for maximum effifiency.

If there are other issues with the car then the fuel economy can be affected too. The vacuum advance being bad can cause a slight drop in economy but nothing you would notice on a huge level. Plug the lines that go to the advance to eliminate any vacuum leaks through the diaphram.

Have you checked for other vacuum leaks and proper vacuum line routing already? These can cause econmomy issues. Also, does it need a tune up including all filters and oil change? Have you confirmed that the brakes are not hanging up or dragging? A valve adjustment may also help in the economy area. If the valves are not opening/closing to the proper amount then the combustion in the cylinder will not be at its maximum potential. Check compression? What octane fuel do you run? Low octane with ethanol fuel is rough on these girls. It is also winter...colder outside which means richer running with choke on longer as well as longer warm up times. Whew, there is just a small list. There are a lot of factors to look at...keep chipping away.

Good luck.

Peace

[dlb]

turtcel gives some good advice there. i would check all those things turtcel mentioned and plug the hoses going to the vacuum advance unit before throwing in the towel. what are your exact mpg/km/L?

after you corrected the timing belt, did you set the timing to 5 or 10* BTDC? if so, are you saying that after doing that, you found it at 0* today? if that's the case, your distributor could be at fault. remove the cap (three 8 mm bolts) and check to make sure that the rotor has a small amount of spring-loaded counter clockwise play. if it does not, the grease in it is gummed up and not allowing the dizzy to advance appropriately. i have found this on several tercel dizzy's. not surprising since it's 30-yr old grease! it's easy enough to do yourself but check and see if that's the issue.