Main IndexAuto Repair Home Search Posts SEARCH
Who's Online WHO'S
Log in LOG

Search Auto Parts

1980 Celica Bad MPG/Bad Accel/Some New Parts

  Email This Post

New User

Feb 17, 2020, 7:42 PM

Post #1 of 4 (328 views)
1980 Celica Bad MPG/Bad Accel/Some New Parts Sign In

  Hi All!

Really struggling with my 20R 2.2L and was hoping someone might be able to help.
I have a 1980 Celica GT with 168k miles, I'm the third owner and have all the repair receipts (if those might be helpful).

The Prob:

- Starts up on the first turn occasionally, other times needs pedal assistance, idles great with a sputter very rarely

- The gas mileage was not great when I first bought the car, about 13 mpg.
- When I start the car it takes approx 3 min to warm up enough to drive (prepared to deal with this)
- Before a 5 min warm-up the acceleration on a scale of 1-10 is a 1
- After driving for about 5 minutes (after warm-up) the acceleration is still very boggy and there's a good amount of shudder (whole car shakes) when leaving a complete stop. Acceleration at this point a 3

- When I get into 2nd or 3rd gear, the acceleration is much more responsive but there is still an odd "budder" noise in the drive train somewhere. Acceleration at this point is a 5

- At times I was getting less than 10mpg until I leaned out the carb (it's back to 13mpg roughly). Adjustment screw is now approx. 1 1/2 turns out from closed
- On attempting to get the smog passed the gas mix was read at 4% and after replacing the carb it was down to approx. 1.3%

- When I park the car there is a mild hot smell that doesn't seem to come from under the hood

-- Trans fluid is bright red, v clean
-- Just had oil change

Very recently replaced parts:
Carburetor (aftermarket I think)

Catalytic Converter

Air Filter
Spark Plugs
Spark Plug Wires
Oil Change

Any help would be greatly appreciated, I'm a bit handy with cars and can't really afford a mechanic right now. Love the car and want it to not be sick anymore

(This post was edited by jensua on Feb 17, 2020, 10:48 PM)

Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Feb 17, 2020, 8:40 PM

Post #2 of 4 (306 views)
Re: 1980 Celica Bad MPG/Bad Accel/Some New Parts Sign In

OK, the first advice I'm going to give you is to NEVER post link in this forum.

Read the rules

The second clarification is you cannot lean out a carburetor. That adjusting screw is for idle mixture only.

It sounds like the engine has a misfire that needs to be located and diagnosed.


We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.

New User

Feb 17, 2020, 10:51 PM

Post #3 of 4 (295 views)
Re: 1980 Celica Bad MPG/Bad Accel/Some New Parts Sign In

My apologies! I'm a forum noob and was confused by the terminology. Also thank you for the direction!

Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Feb 18, 2020, 5:13 AM

Post #4 of 4 (282 views)
Re: 1980 Celica Bad MPG/Bad Accel/Some New Parts Sign In

Some thoughts to get started: You've replaced Air Filter, Spark Plugs, Spark Plug Wires. Hope you inspected the old ones if no change or if no better check the new stuff.
You could cancel plugs one by one but use a ground wire to open wire end at the plug not leave it in air. Watch for stray spark and see if one drops RPM more than another. Focus on that cylinder.
Vacuum nightmare for these carb and all. It wasn't intended to use any "ethanol" or long times sitting with that it's water absorbing all hell busts loose. Vacuum leaks high on any list by age over 30 years ago never mind now. Rated hose mandatory to be top shelf if found.

To find anywhere vacuum is (you said you were handy so know gaskets or anything) I like to use spray (carefully can harm things too) either risk of a flammable (read containers) spray carb/throttle body cleaner or Bra-Kleen by brand will put out a fire - read it by that brand.
Either way with engine at idle spray around the flammable (AYOR) will usually raise idle speed the other will lower it or stall it out. Note the item or spot it shouldn't do anything with that for testing.

If fuel itself suspect I find just tad of Sea Foam liquid can really fix a problem if a varnish or clog but can't fix metal debris in the wrong spots.

Last for now: You said up top turned mixture out? Should be the only thing that's just idle mix and mid throttle not the mix when under any load really. Glad you have one or two it's best not to mess with those once right mix is found but great you can clean with those out totally.

Good luck. None of that costs much but your time. IDK how anyone deals with their own if not really handy plus seriously understand the damage of Ethanol in fuel has ruined more assorted stuff of my own than anything going back to a 1948 still doing fine no longer will use any more Ethanol wrecked it's carb's few gaskets OE kit on hand too to do that someday,


  Email This Post

Feed Button

Search for (options) Privacy Sitemap