Stuttering 1986 C-C-Corolla. Please Help!

[Amethyst]

Hello everybody!

I own a 1986 Toyota Corolla Hatchback, automatic with an auto choke. (not sure if an auto choke goes without saying with an auto...)

Anyway, I've got a bit of a problem. Firstly, my car has trouble starting at any time of the day, whether it's hot or cold. I need to pump the gas a lot to get the engine to turn over, then it coughs, splutters and dies. I start it again, hold the revs high (i don't know how high cos i have a clock in place of a taco) and leave it running for 5 minutes or so. Then when i put it into gear, it coughs, splutters and dies. Back to the beginning, start it up, put it in gear, rev the engine, it coughs a bit, levels out, and eventually idles ok. Then I can drive it away.

My second problem is that as i'm driving along, and the engine's warm, when I slow up at a set of lights or roundabout or something, the engine starts chugging, coughing and if I don't accelerate in time, it conks out. It will start up straight away and sometimes after that will drive smoothly to my destination, other times will repeat the coughing and dying.

Here is a list of things I have had checked, repaired, replaced, altered, etc.!

1) Carby: Jets cleaned, float level reset, gaskets replaced. (thanks Dad!)
2) Oil filter replaced (11/03)
3) E.G.R. Valve repaired (11/03)
4) Radiator cap replaced (11/03)
5) Ignition module replaced (02/04)
6) Choke assembly cleaned, lubricated and rechecked (02/04)
7) Engine tune reset (02/04)
8) VSV Vaccuum line replaced (02/04)
9) Carbruetor circuits checked (02/04)
10) Auto choke reset (was running rich, now running lean) (06/04)
11) Fuel filter replaced (02/04)

Also within the last 12 months I have had the sparkplugs replaced, a new battery, a new air filter, 3 flat batteries and a very lean bank account. My dad knows a lot about cars, but this has him and our local machanic stumped, as well as the mechanics at Toyota. Has anyone come across this problem and if so, how do you fix it?

My next move is to have a look at the butterfly valve and make sure it isn't seized or loose. The engineers at work (I work for Qantas, so they should know a bit about engines!) suggested it might have a loose pin, or be seizing. Another suggestion has been to check the idle mix. Please help! I love my car and it doesn't deserve the scrap heap yet.

[Flashmn]

10) Auto choke reset (was running rich, now running lean)

its supposed to run rich when its on ;P
did ya change your plug wires? did ya check the compression of the engine?

[Amethyst]

no, and i don't think so. But after having a look at the Butterfly valve i found that the spring-loaded action isn't working. So it opens ok, but doesn't have the spring in it to close it back up again as the throttle moves forward. Maybe the coiled spring (on the shaft on the right hand side of the carby near where the throttle cable is) has come unhooked, or snapped or something.

The plug wires are a good idea. Are they expensive? And (oh no, i'm starting to sound like a girl - hey wait, i am one, but still...) how do i/dad/the mechanic check the compression i.e. what is it, where is it, what does it do and what does it look like?

Thanks for your suggestions

[thespud]

The plug wires are a good idea. Are they expensive? And (oh no, i'm starting to sound like a girl - hey wait, i am one, but still...) how do i/dad/the mechanic check the compression i.e. what is it, where is it, what does it do and what does it look like?

The plug wires are not too expensive (usually). Mine cost $120 for premium wires for a 95 at Auto One (not sure if you have them in Sydney - Supacheap will do).

To check the compression, you need a compression tester, which can be expensive so it's probably best to let your mechanic do it, unless your dad has one.

The compression testers plug into the hole where your spark plugs go and just test how much air compression is in the firing chamber of the cylinder at it's highest level with the valves closed. it is a relatively simple procedure, however i know i had trouble finding a tester that would reach to my plugs (not sure if yours would be roughly the same), and when i did find one, it was upwards of $300 - pretty expensive for something you will not use very often...

Hope this is of some help to you.
Spud

[Amethyst]

Hi,

Thanks for the advice. The latest in the saga is i got a new battery under warranty (the old one had a small short in one of the cells), then we replaced the alternator brushes and regulator. That's stopped my battery going flat every night. But i'm still having to start the car 2 or 3 times every time because it starts, then peters out, then i've got to start it again, then it fluffs and dies, then i can start it again and it'll stay on.

Next plan is to do the compression test (dad's got a tester), change the spark plugs and the plug cables/wires, and replace the distributer cap.

It conked out on me again last night when driving home just off the harbour bridge (not a nice place for it to happen in an 80km zone). I noticed before it died that the car was lurching forward when i put my foot on the accelerator (to get it up to 80km) and then lurching backward when i took it off (i was coming up to a bit of traffic). This lurching forward and back kept up for a bit, then when i slowed right down and rolled up towards the backed up traffic, my car coughed once and the engine promptly turned itself off. There was no shuddering like it used to do. It started first go luckily.

I'm really hoping the plugs, wires and distributer cap could be contributing to this problem.

Also, we checked my friend's 86 corolla butterfly valve and it operated the same (we checked my vacuum lines and his, and they worked exactly the same as mine, one had stronger vacuum pressure than the other - Is that normal?)

I just can't believe that i can be the only one with these problems with their car, and that no mechanics seem to know what the hell the problem is.

[demetriuswoods]

i was just wondering if there was ever a solution to the problem. i own an '87 ae86 sr5, and have almost exactly the same problems. i have no mechanic experience, but i do have some buddies that do know some things. im thinking about getting the carb replaced cause that is what most people are suggesting, but i've already spent over $400 bux on a car i got for free. just wondering if it'd be worth the trouble of replacing the carb, windshield, and wiring.