Problem with Lack of Power and Odd Sounding on Accelleration

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FranklinTheWagon
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Posts: 18
Joined: Mon Feb 18, 2019 7:34 pm
My tercel:: 1983 Toyota Tercel 4WD Wagon

Problem with Lack of Power and Odd Sounding on Accelleration

Post by FranklinTheWagon »

Hello everyone,
So I' having some trouble and am in need of some advice on what might be wrong. I have a 1983 Tercel 4wd Wagon with a 5+1 speed manual, the original carb, and the original 3AC engine.
My issue started the three days ago on the way to a campsite. We were on a pretty rough dirt road not going particularly slow but nothing too extreme and there were some 4-8 inch mud puddles we slowed down to go through; nothing crazy. I started to notice that the car was seemingly going a little slower and struggling on the uphills but it was insignificant enough that I figured I was imagining it. We ended up about 25 miles into nowhere and as I parked to camp we really struggled to pull up the little hill and my buddy got out and pushed to assist. The next day as we headed out I realized there was a real issue. Even in the EL gear I couldn't pull up anything more than the mildest of inclines and we couldn't get going faster than 25 to get enough momentum to pull up hills. We ended up trekking to where we had service and getting the car towed back.

So the current situation: The Terc seriously struggles to accelerate on level ground and will quickly lose speed in any gear when going uphill at all. Along with that, When you press the gas pedal and the rpms rise it sounds very 'lawnmowery'.
What It (seemingly) is not: I have a brand new muffler and the Cat is in good shape, when testing the pressure at the 02 sensor its about 1 psi so the exhaust isn't clogged. I just now replaced the fuel pump and the filter is only about a week old. It doesn't seem to be a misfire (I'm less certain on this one); I disconnected one plug wire at a time and with each one it was clearly dropping a cylinder.

Prior issues: It would diesel at shutoff a little at high altitude and a lot at low altitude, I've lately been getting only about 22-26 mpg city or highway, to start I have to crank for a few seconds and give it a little gas once it starts running or it'll stall out.
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dlb
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Joined: Mon Jul 06, 2009 9:03 pm
My tercel:: '87 sr5, '83 dlx parts car
Location: bc, canada

Re: Problem with Lack of Power and Odd Sounding on Accelleration

Post by dlb »

Is the air filter clogged?

I would also check all the vacuum lines on the carb and make sure you don't have a big leak. Next I would check the timing, check the fuel level in the float bowl of the carb, pull the spark plugs and check them, and I would also change the fuel filter again just in case it failed or something just happened to get stuck in there.
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Petros
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My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: Problem with Lack of Power and Odd Sounding on Accelleration

Post by Petros »

possilbe you wiggled off a vac line somewhere on the rough road. usually it will idle rough, and be down on power with a vac leak.

could also be a marginal ignition coil, it will spark okay without load, but under load/high rpm it generates a weak spark.

check for cracks or leaks in the fuel line up stream of the fuel pump, it may not leak fuel but have find pinholes or cracks in the rubber flex line up stream of the fuel pump will suck in air instead of fuel (check the fuel level in the window on the carb, (if it is fuel starved it may show up in the window).

Verify the throttle is opening all the way, the cable adjustment may have become loose. verify the mechanical spark advance is working, if it is stuck it will idle okay but be down on power at higher rpm (this can be done with a timing light, or you can remove the distributor cap and see if the rotor is free to rotate, if not lubricate it and work it loose. while you are at it check the spark timing, it works best at 10 deg BTDC rather than the emssions compliant factory 5 deg.

get the front cover off and carefully inspect the cam timing belt has not jumped several teeth, this can happen with a worn belt or a loose belt tensioner.

if you don't find anything, try a compression test just to verify you have good compression. not likely, but iti is easy eliminate that.

good luck.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
atoyta
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Posts: 137
Joined: Thu Jan 29, 2009 11:32 pm
My tercel:: 3 wagons now
Location: Monroe, Washington

Re: Problem with Lack of Power and Odd Sounding on Accelleration

Post by atoyta »

They are also prone to collecting moisture in the distributor cap after running through water. I usually run a thin bead of silicone grease across the lip of the cap where it meets the distributor when putting it back on.
FranklinTheWagon
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Posts: 18
Joined: Mon Feb 18, 2019 7:34 pm
My tercel:: 1983 Toyota Tercel 4WD Wagon

Re: Problem with Lack of Power and Odd Sounding on Accelleration

Post by FranklinTheWagon »

Air filter is nice and clean and I couldn't find any vaccum leaks. Plugs are a little foul; it burns rich and I was planning to finally tune the carb this week. I haven't done carb work yet so I'll admit I'm more ignorant in that area. I'm out of town right now so I can't check much until next week but I had a friend check the float for me and with the car running or off there is no fuel at all visible in the sight glass. Every time in the past I've checked in the past its been in the dead center of the window so this is new. What might that indicate?
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