lack of power - KE70 4K motor

[WA_TRD_83]

my super Rolla has hit its first stumbling block after a few weeks of reliable driving...

she's got a total lack of power - and I don't just mean cos its a 4KC motor
so wierd that it was running perfectly fine one day, and then went to drive to work the next day and this problem occured

basically coughing and spluttering and struggling to idle. I can put my foot flat to the floor and it just coughs an pops and backfires. Can't even get the car to move under load, it just stalls.

upon purchasing from the previous owner, I know the following things have been claimed to be replaced within the past 12 months (and they still look in good condition):
- coil
- leads
- new mechanical fuel pump
- battery

last weekend
I replaced fuel filter, distributor condensor, and sprayed a hell of a lot of carbie cleaner in.
Still seems to be getting fuel in the carby, so seems to be more an ignition/spark issue.
checked coil, still sparking

this weekend
new spark plugs
new dizzy cap
new rotor
(new points not in stock - now on order)

All vaccuum lines appear to be connected and in good condition, nothing dried out or cracked that I could see.

so far STILL no joy in fixing my problem.

any suggestions on things to check/test would be helpful


cheers
Damo

[2jzhilux]

serious suggestion

Swap a couple of leads around the wrong way so it still runs with the aircleaner off and get it to backfire out the carb, then swap them back could be something blocking the pilot jets in the carb.
Had to do this regularly on a corolla i used to have because i couldnt be bothered cleaning out the carb.

[WA_TRD_83]

serious suggestion

Swap a couple of leads around the wrong way so it still runs with the aircleaner off and get it to backfire out the carb, then swap them back could be something blocking the pilot jets in the carb.
Had to do this regularly on a corolla i used to have because i couldnt be bothered cleaning out the carb.

thanks mate. tried your suggestion - got some good backfires out of it, swapped the leads back ... started up and idled ok - but still no power when I put my foot down.
so tried it again, switched some different leads, and switched them back... started up, problem still exists.
so don't know if its worth changing the carbie or getting it rebuilt - or if thats not the actual problem ?

[CrUZida]

Timing?
Could dizzy have moved?

[lexsmaz]

It could be a lot of things, An easy try is you could start it up again & bring the rev's up slowly & at the same time pull out the choke if it smoothes out & the rev's increase by just pulling on the choke you are chasing a fuel issue .... I suspect it could be a faulty condensor, i would change the condensor again or just put back the old one to see if it improves how it runs & also what are the points like in condition & the gap & check the timing too ..

[WA_TRD_83]

Timing?
Could dizzy have moved?

can't really adjust the dizzy - only the points gap.
not sure why it would be working one day, and then the next day just fail though

[lexsmaz]

Why can't you adjust the dizzy ?????

[WA_TRD_83]

Why can't you adjust the dizzy ?????

depends in what way you mean adjust the dizzy?

[RHINO145]

The 4Kc in my KE55 had a similar problem, it turned out to be a wire off the side of the carby, still never worked out what it does id take a picture of my culprit but i have a 5K and weber in now.


or it could be because its a K series

Edit: this may have been on the weber actually... way to many bloody corollas

[CrUZida]

Damo, you can loosen a bolt on the dizzy and rotate it about 15degrees - ie to set the timing.
Its common for this bolt to come loose, and the dizzy to move to one extreme, giving similar symptoms.

[Matt-AE86]

Do your ignition points and shit. That helped my 4AC become awesome before I ripped it out years ago with Adz. Other then that. Nangs and nang canister hose hooked up to intake + 98ron + advance timing.

[stahlz_ae86]

Triple check vac lines close to carby, especially underneath.

[thechuckster]

assuming that you've got spark, look at the carbi again.

If it's stumbling/missing when going lean - accelerator pump - check by removing air filter, look down throat and pump pedal, you should see squirt of fuel

If it's just not getting enough fuel (aka making any power) on a steady throttle - main jets and/or float level - you can do a nasty unblock process by removing air filter and bringing the revs up as high as possible then quickly cover the carbi inlet to choke it 100%. Float level you have to inspect and/or measure.

Personally, i think carbi's are the work of the devil and EFI was sent down by <insert god/diety of your choice> to rid the world of them.

[WA_TRD_83]

ok - looks like I'm going to have to remove the whole air intake assembly then and have a better look in and around the carby then

I was planning on an engine conversion - but maybe in a couple of years time, not after couple of weeks owning it!
need to get this economical little 4K running right again!

[WA_TRD_83]

Do your ignition points and shit. That helped my 4AC become awesome before I ripped it out years ago with Adz. Other then that. Nangs and nang canister hose hooked up to intake + 98ron + advance timing.

thanks Matt
will be changing ignition points and checking timing as soon as the parts come in. they still look pretty good/newish - but may as well change them to eliminate that as suspect