Not a 4wd... 1990 Corolla not running right

[Petemcc]

My girlfriend has a 1990 ee90 toyota corolla with a 2e carbed engine. It has been running a bit rough when driving and really rough then idling as well occasionally running on when turned off. I started buy changing the plugs which where in very average condition. This helped a little but the idle was still really average. I also replaced the rotor and dissy which were old and crap too. This didn't seem to help at all.

The car is now running better when going but is idling as bad as ever and has started to run on really badly. The other day I turned it off and it ran on a for about a second then revved up and popped off a breather pipe that goes onto the air cleaner and is normally under suction rather than pressure!

I now have her driving it round but putting it in 5th and stalling it to turn it off rather than letting it run on haha. I am working out of town and have thursday and friday this week to get it fixed when I am back.

My only thought is that it might have an intake leak (kind of sounds like it does) So I was going to start by replacing some gaskets and vacuum hoses. But I would really like to have a better idea of what it is before I start replacing stuff for no reason. The carby is a really weird looking thing with a horizontal slide rather than butterflies and has vacuum hoses and emissions crap for Africa!

Anyone got any other ideas?

Cheers,
Pete

[Petemcc]

Forgot to mention it is also hard to start when hot, you have to hold down the gas and it will slowly come to life

[mudlva]

get a can of engine start have the motor idling and spray the crap all arond the carb and intake area if motor starts to rev then concertrate on that area to id where the leak is.
it mite take a couple of cans if the leak is hidden beneith stuff

[mud_slinger]

if its running on odds are there is a decent amount of carbon build up in the combustion chamber and not much you can do apart from pull head off.

clean the carb with carb cleaner, it prob need a decent clean


Buy a nissan

[Taz]

if its running on odds are there is a decent amount of carbon build up in the combustion chamber and not much you can do apart from pull head off.

clean the carb with carb cleaner, it prob need a decent clean


Buy a nissan

Nah you can stick a garden hose in it. Haven't you seen the vids?

[Swamped]

Mine did the same. Could never diagnose the over running thing. Had the head off and cleaned it when I did the headgasket. put a recon kit in the carb and it still did it. When I did a top tune it got even worse. You could lock it up and walk away with it still overrunning. Try drown it with the throttle and it would rev...... well sorta. It was slightly better with 95 than 91 gas I noticed but thats about it.

I didn't have the performance problems you talk about though except under load it would lose a lot of power for some reason.

Just sold it cos I got fed up with it.

[pruggerdore]

ignition timing to advanced will typically give those sympyms

[scohar]

ignition timing to advanced will typically give those sympyms

x2, Check ignition timing, and goto your nearest subaru dealer and ask for upper engine cleaner bout $20 a can, only add in product that I have ever seen results for it sucks up through a vacuum hose while the car is running. Check it out on Youtube its pretty scary looking but it doesn't screw anything up which you would think by looking at the vids, otherwise known as SeaFoam.

[pruggerdore]

also tho there should be an electric solanoid on the carby to stop the running on by cutting the power to the solanoid when you turn the key off allowing a plunger to block off idle jet thus cutting the fuel at idle so no fuel means it cant run on.

[Landynut]

take it down some gravel roads well beyond reccommended RPM.... poor thing probably just needs a good thrashing, she'll come right! (ur g/f i mean)

could be just a bit of crap in the carb, a really hard thrashing always sorts it out, works on the mrs anyway......

if it doesnt come right, or blow up- after a really good rev-out session you probably need to set the valves and timing..... even a tiny ammount of intake air leak would be causing it to overheat wouldnt it?

fuel, spark and air....
you said you've replaced the plugs and dizzy cap & rotor but did you visually check the spark? could be just a weak coil or bad leads...
put a screwdriver (with a plastic handle) in the spark plug end of a lead, start the motor, then earth it out. if it kills the motor, the lead is good... if it keeps on chugging, the lead is dead.... repeat that for all four leads, just dont give yourself a shock, its likely to hurt....

I've tuned up a few of those rolla motors, quite simple but quirky little engines, very wierd setups, if i remember rightly the plug leads are basically laid along inches directly above the manifold?? kind of stupid really - think they tend to cook leads for that reason....

could be the automatic idle / automatic choke thing being a pain in the ass causing the run-on, especially if its not burning fuel efficiently ....

if its not a simple fuel/spark/air problem, borrow a timing light and check the timing, then the valve clearances...

if still to no avail, i've got a 12 gauge and a sack full of buckshot - could have some redneck fun with it

good luck!

[Petemcc]

Cheers guys I was heading towards some similar conclusions. auto choke and that gear is one I have had issue on before on another corolla. At this stage I have had bugger all time to have a good look at it but will try to spend a bit of time on it towards the end of this week when I am back in town.

Carbon build up in the cylinders is one I had thought of because she is always keen on running the cheapest gas which we all know is pretty crap stuff here.

and yes in my limited time i had to look at it I did try the give it a bloody good thrashing trick. Didn't work on either of them!

Cheers,
Pete

[Petemcc]

Also does anyone have a link to a manual for these engines. I wouldn't mind getting a look at some stuff on the carby set up and the the valve clearances etc but haven't been able to goolge find one...

Cheers,
Pete

[NJV6]

Run on thing can't be carb/fuel/spark related as the key is turned off!

She's carboned up mate, carbon gets hot, on she runs.

The old Jeep was like that, turning the key off was done in time with letting the foot off the clutch...

Time for a headjob

http://www.youtube.com/watch?v=74-BI-iI-K8

[COMILUX]

Thats is common symptons in those engines.

they run a twin ventury carb which are common for failing in old age. generaly carbs cant be fixed and are very hard to find a good second hand one.

Good luck

[Landynut]

I've had some little petrol motors like that which have gone over a million km's and never had a carbon issue, always running the el cheapo 91 gas.... petrol motors are kind of self cleaning in that respect - it would take bad timing advance/retard and/or bad valve clearance to get carbon buildup happening in the first place wouldnt it ?

makes sense to treat the root of the problem, not the symptom.... so get a timing light on it first

as to the carb being poked, highly likely.... whip the carb off and see if you can get a ford laser / mazda 323 carb to slap on there - if its the wrong ID you can get an engineer to make up an adaptor for bugger all, will probably run alot cheaper too, and rebuild kits are readily available

for a manual, if you cant get it online you'll have fork out 40 odd bucks at supercheap/repco, they can order just about any manual if they dont already have it in store...

you could always ring toyota, if u hassle them they will tell you the valve clearances.... I've done that once before

this is the procedure, and could even be identical to your motor by the looks:

http://www.tercelreference.com/articles/valve_lash_adjustment/valve_lash_adjustment.html

[nizmo]

hi, some of them 2e carb motors has a stupid diaprham carb, almost like a motorbike carb with a big slide, bin it and get a normal one, at work we made up and adappter plate and mounted a cortina carb and jetted it, went really well for 1300, we have a mint rebuilt engine, port polish cam and that carb set up but the bottom end is stuffed, if your interested let me know and ill find out how much,

[Landynut]

yeah i put a mini minor carb on an Xr200 once . . . went like a rocket, but back then fuel was cheap, and it wasnt a runabout laser/323 carbs are a dime a dozen and im fairly certain they will just slot straight on, good reliable wee carbs to.... In fact I think I may have one or two of em in a box under the house somewhere....