HELP Corolla running badly, rough idle, vibrating, low power

[lewis_waters]

Hi Guys

I recently bought a Corolla AE92R Automatic 1993, 4AFE
150,000 on the clock, in good condition outside and in.  

It had been sitting for a few months before I bought it, but seemed fine. I drove it a few times after I bought it, no issues. Then on a very rainy day I took it to the shops, drove fine, then restarting the car to come home, it started running badly. In Park it has a rough idle, in Drive and Reverse it stalls straight away, I have to keep the revs up to get moving, and once moving it really struggles to accelerate and stutters and vibrates quite a lot, it sounds quite sick. I managed to get it home stalling at every lights.  

A few days before I had replaced the distributor o-ring and put the dizzy back on without setting it properly, but the car ran fine regardless.  

I have replaced the spark plugs, no difference.  

Then I reset the dizzy by ear, it still runs really badly and stalls in Drive and Reverse. Basically it made no difference, but I was worried I had damaged the dizzy so I looked further into it and the symptoms matched up with a bad coil so I replaced the whole unit with a junkyard dizzy that seemed to be in pretty good shape, made no difference at all. The original cap and leads are still installed so I wonder if I damaged the cap? there is some slight oxidising or melting of the pins, but they are intact, I’m not sure how fine the tolerances are with the pins, otherwise the cap and leads look like they are in good condition, no cracks, no evidence of moisture in there.  

I wonder if there are other obvious things I can test for at this stage?

You might have figured out I am fairly new to car maintenance, but I really want to learn.  

Cheers

Lewis

[Rhymes with Paris]

Have you cleared out all the fuel system,and got fresh fuel in ?

Bearing in mind it had stood for a while.

 

[lewis_waters]

No I haven't, but could the old fuel have caused a blockage somewhere? over the few days of it driving fine?

[Rhymes with Paris]

If the fuel has been in there a long time,it can get a bit treacly and clog up things like injectors,or carburettor jets if your car has a carb .

Also if the tank is left half empty on an old car, then tiny flakes of rust can form , and get sucked into the small pipes and tubes.

Have a look at the fuel filter, and see if it's full of gunge or dirt.

And of course if you are sure that you are getting a spark in all cylinders at the right time, even though you have swapped out a few things.

Maybe check HT leads and distributor cap again and make sure all sound and dry.

With an older design engine like this though,it is usually HT electrics or fuel stopping them running right,so back to basics really,if you have fuel,air, and sparks it should run ok.

But please bear in mind, my mechanical knowledge is very limited, so I could be way off, there are many others on here who have much more tech know how, and may offer help.

 

[Rhymes with Paris]

Just had a further thought, I take it you've put new points in and correct gap?

Of course I may be going too far back here to prehistoric times when cars had these.😄

Electronic ignition a different matter, but I don't know which it would be on a car of that age.

 

[Red_Corolla]

6 hours ago, Rhymes with Paris said:

Just had a further thought, I take it you've put new points in and correct gap?

Of course I may be going too far back here to prehistoric times when cars had these.😄

Electronic ignition a different matter, but I don't know which it would be on a car of that age.

 

Probably safe to say electronic on a post-1990 car, Paul.

If the coil or HT ignition components are in doubt then it's possible to gauge spark strength by using a 12v test light (bulb only, NOT LED) as a substitute earth electrode and see how far it will jump - it should manage close to an inch or even further outside of the cylinder, at atmospheric pressure. Word of warning, though: HT leads tickle when they're live 😆

[lewis_waters]

I did some further testing based on suggestions on another forum.  Removing the spark plug leads while the engine is running.  The engine stalls when removing leads 1 and 4, but no change when removing 2 and 3, and I can see the spark arching from the rubber boot (near the start of the stem) to the spark plug tube as I lift it up.  So next I am going to do a compression test.  I have a feeling there might be a problem with the head gasket, I can hear a regular small puffing sound when the engine is running.  Or could I have accidentally burnt some valves by running it with an incorrectly set distributor?  I guess just wait and see with this compression test, I have a friend who can loan me one.  

It has fuel injection and electronically controlled ignition

[Red_Corolla]

It's possible the head gasket has failed between 2 & 3, but wait and see. I think the compression test is a good next step. If there is a serious issue with compression, you can normally hear it in the sound and rythm of the engine while cranking - it will be irregular.

[lewis_waters]

Hi guys.  

Little update here
I replaced the cap and leads, no change.  
I removed the fuel injectors, cleaned and tested them, and replace the rubber seals and micro-filters, no change.  
Got it to a good mechanic, he did a compression test and found that cylinders 2 and 3 were at Zero. So its a blown head he says. Water is coming out of the exhaust.  
I'm going to remove the head and inspect it when I get a chance.  
Fun and games!

Lewis