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Hey, new to the forum. I bought an '81 Celica GT this spring and it's been running rougher and rougher the last month or so. I'm hoping you all can help with a few problems I'm having with the car...

The car had a slight jolt/sputter while driving when I bought it, but it was hardly noticeable. Within the past month though, it's gotten much worse. It jolts pretty violently at times, but runs perfectly fine when it wants to.

Then the car started stalling. I would start it with no problem in the morning, make a few turns on my way to work, and it would die at the same stop sign almost every day... usually after about 2 minutes of running the engine. It would start back up without a problem, and run mint the rest of the way. That went on for about 2 weeks until it got worse. Now, when the car's running rough it wants to stall every time I let my foot off the gas. It doesn't happen all the time, though. Sometimes the car runs perfectly. If the fuel pump was dead the car would run rough all the time, right? I replaced the fuel filter, and I honestly thought I'd fixed to problem, but after about 4 days it started running rough again.

Now the car's killing batteries. I'm assuming it's an unrelated problem, though. I haven't had any money to fix the problem, so I haven't even done much investigation under the hood. I've been alternating between two batteries, charging them at home overnight and keeping one in the hatch at all times to swap with the one under the hood once it's too drained to start the car, but I don't know how much longer I can keep re-charging/swapping batteries like this. They've both been drained and re-charged at least 5 times each in the last week and half... that's gotta be damaging something, right?

A few friends think I've got a bad ground somewhere. I know the last owner had a sub & amp put in it and had whoever did it wire it through the factory eq in the dash but they screwed up and it always crackled and popped the right speakers. Could a bad ground be causing some of these problems? I dunno if the car's got a manual or electric fuel pump, but if it's an electric fuel pump, that could be causing the stalling and rough running, right? A bad alternator could be messing up an electric pump too, though right? I'm not sure how to check for a bad ground. I've replaced the positive terminal and cleaned the posts really well on both batteries...

My plan right now is to pick up a Haynes manual tonight or tomorrow, get the alternator out of the car on Sunday and get it checked. Hopefully it's dead and I can just buy a new one and that'll solve that problem, right? As for the jolting/stalling, I'm assuming the Carb needs to be rebuilt/replaced? I ran carb cleaner through the car when It started acting up and, if anything, it made it run worse.

Any other ideas as to what could be causing the problems? Is there anything else anyone can recommend I do/check? Thanks!
 

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Discussion Starter · #2 ·
P.S. I thought I'd post some pics...

It's an '81 GT. 170,xxx KMs, 5spd, 22r, really great condition. I got it for 2700 CAD in March and it's been great until these problems popped up. I'm not complaining, though. I couldn't possibly hate this car...









 

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Wow, do you have a lot going on here.

About your engine running rough, the first thing I would do is to check all your vacuum connections. I make a point of replacing all my vacuum lines every two years or so if I'm using regular vacuum hoses (yes, I mean all the hoses in the entire engine compartment, except those four-house ribbons, and the long ones for the AI and A/C subdamper). I've also been getting fiber reinforced hoses lately (Gates hose 27000 works well for me), because they last longer. It seems like a lot of work, but vacuum leaks will cause rough running.

One thing about that is that you should not merely copy the way the vacuum hoses are already routed because many mechanics are unfamiliar enough with these older cars that they will get it wrong for you. You need to get an original Toyota repair manual, not a Haynes or Chilton manual, and follow it exactly. They are easy to find on eBay. Also if your carburator has been replaced, there may be extra vacuum ports that can confuse you. Simply cap these, but make sure you're using the right vacuum ports.

About your car stalling, the 81 Celica has a feature where the car will automatically open the EGR valve when you turn the car off. If that system malfunctions, it will stall the engine at idle. This is usually an electrical problem. The VSV that controls that is mounted on top of the engine at the back. You can test this by disconnecting the vacuum hose from the EGR valve and see if it still happens.

Your battery draining sounds like a basic electrical problem. To find it, I would connect the battery to the car through an ammeter, and make sure it says there is power running through the car. Then remove the fuses one at a time until the power drain goes away. When you have identified the circuit that is draining power, replace the fuse, and disconnect all the parts that are on that circuit, one at a time, until the power drain goes away. If everything on that circuit is disconnected and power is still being drained, there is a short. Use a continuity tester to find the wires that are connecting the powered part of the circuit to the ground. If a component is the blame, replace or remove that component.

Just make sure not to start the engine with an ammeter connected because that will use more power than most ammeters can take.

If you get an original Toyota manual, there is a fold-out page just inside the back cover that has the car's entire electrical system on one side, and just below it is a chart of the entire car's wire harnesses. I've found this invaluable for doing electrical repairs on my car.

I hope this helps you out. Good luck with your car.
 

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