[Ratman407]

Been searching and I can’t find the answer or atleast not with the words I’m using so I’m going to have to ask here
So forgive me if it’s been asked before


I have a problem with my 91 g13 stock motor and all I can put it down to is something carby related
The problem is any time the clutch is in and the revs drop to idle it cuts out
Most the time it happens when coming to a stop but it’s also happened when changing gears if the clutch is in to long

The other part of the problem is it’s very random no pattern to it
It will do it for a few days then be good then random start again
Though it was most likely dirty fuel but swapped out the fuel filter and hasn’t seemed to help

Think that’s all if it
Thanks for the help guys

[bumstein]

Hmmmm.. the stock carby is pretty ordinary now. They’re old and have served their better years long ago.. You can have it professionally rebuilt and it will still have wee issues. I’ve tried it and it’s not a complete solution.

My suggestion is get hold of a corolla 4K carby or a Weber (or FAJS Weber copy) on depending on what suits your use..

Just curious, does it happen with the clutch out, car in neutral and idling away?

[Ratman407]

sometimes it will other times no it will stall

sometimes it will start fine with no throttle other times you have to give her a bit to get it started

[Ratman407]

something like this
https://www.ebay.com.au/itm/Carburetor- ... Sw5cNYPPSi

How hard are there to fit?

[bumstein]

Yepo much like that one..

I haven’t installed one myself so I’m not the guy to give you the ins and outs, but this should give you the info:

viewtopic.php?f=17&t=16365

My understanding is they’re quite easy to install

[Ratman407]

cheers mate read a bit and I'm going to get one

[bumstein]

Good choice [emoji4] the Weber (of Faj’s) are good for the road but they tend to overfuel on steep inclines. The 4K are cheap and easy and work well by all accounts. Let us know how it goes

[Ratman407]

Anything I can do short of pulling the carby completely apart to get it going untill 4K gets here?
It’s at the point I can’t even driveit to the shops safely as it stalls out 2 or 3 times

[bumstein]

I’m no carby genius! They’re somewhat a black art as far as I’m concerned..

if you’re at the point where you can’t use it anymore then it seems like a good time to have a random play!!

Perhaps remove the jets and see if they’re blocked. There’s two brass plugs on the side of the float chamber, undo them and you can unscrew the jets with a flathead screw driver.





^this is a blocked jet..

Other than that unleash a can of carby cleaner and see if it helps!! If you start pulling the carby apart you may find small parts spring out and it’s a bastard to find what bits go where (if you can find the bits)

Check for vac leaks in the lines or where the butterfly shafts sit on the throttle body? I’m clutching at straws here

[primejo07]

viewtopic.php?f=5&t=54335&start=30#wrapheader

Read that thread by Pete_79. He had a carby issue and it was a simple fix. The answer is on page 2

[bumstein]

I thought about the clutch switch but that problem seems to present as a power issue under load with the clutch out. Ie idles fine, revs fine but in gear with the clutch out it dies in the ass.

Worth a try but doesn’t seem to match the problem that Ratman is describing. He’s saying the problem presents with the clutch in and idling.

Just curious Ratman, you say if the clutch is in too long when changing gear or while idling at lights etc it cuts out (intermittently). If your pulling up and slip it out of gear with the clutch out rather than in does the problem still happen?

[sideways]

bumstein wrote:

Just curious Ratman, you say if the clutch is in too long when changing gear or while idling at lights etc it cuts out (intermittently). If your pulling up and slip it out of gear with the clutch out rather than in does the problem still happen?

This. ^

It doesn't seem like Pete's problem but it could still be an EGR issue, with the EGR staying open when it's not meant to or simply the EGR valve not closing fully.

Personally, I'd remove/block all the related vacuum lines/solenoids and block the EGR valve. The whole system is a source of vacuum leaks and running issues. If you're looking at fitting a different carby then you probably aren't very concerned with meeting emissions anyway.

It's easy to remove and plug the vacuum lines that actuate it just to test. You can go one step further and block the ports in the EGR valve to make sure it doesn't leak.

Otherwise you can play with idle speed and mixture. Just turning up the idle a bit might stop it stalling.

[Ratman407]

Yeah still happens
Even atm when you start it got to give it revs then once you drop the revs it cuts out without touching the clutch or gears

About to pull it out and have a look

[Ratman407]

So pulled the hat off the carby and was playing with the throttle and noticed that the butterfly that’s not under the choke side doesn’t move is that normal?

[bumstein]

That I’m guessing will be the secondary throttle which opens when you go full noise. I think they are vacuum activated rather than linkage so unless the motor is under load it won’t open. Let me check in the morning with one I have at home, however your problem is evident at idle which means both butterfly’s will be fully closed. I wouldn’t think that is your issue

[Ratman407]

Doesn’t look like it’s the jets

Pulled them out and cleaned them still no better so no idea now unless it’s timing but that doesn’t make sense to me

[bumstein]

The more things you can do like that the more problems you’re ruling out. So check the timing while you’re playing. Checking spark etc is a good idea too..

My money would be on a vac leak somewhere. If not the vac lines, perhaps air getting in somewhere like the butterfly shafts or the like.

[Ratman407]

Anybody know what size the vac lines are ?
Plan to get a meter or so and replace all the lines

[bumstein]

8mm vac lines.. and no the secondary butterfly does not open with the throttle linkages, think it’s vacuum operated.

Also check over the Manifold and other areas for anywhere it may be leaking air and/or fuel. My primary butterfly shaft is worn and leaks. I also spent waaaaaaayyyy too much time trying to find a fault where cylinders 1&2 weren’t running properly only to find that a vac port on the Manifold was open.

Again, be aware that you may be chasing a fault that cannot be fixed ie carby is old and rooted. All this is really only to confirm that the carby needs replacing as you already suspect.

[Ratman407]

Yeah local mechanic said to spray start you bastard around the carby andsee if the revs show up meaning there’s an air leak

Yeah it is worked that out while I was sitting there playing with it andclezning the jets

Yeah all I’m doing is trying to fix it while I wait for the 4K should be here by Wednesday

[bumstein]

You’re on the right track then you’ll know for sure when you change the carby!!

[Ratman407]

Lol yeah unless it doesn’t fix the issue sad face

[Ratman407]

Well start you bastard didn’t work so any other ideas ?

[bumstein]

Look forward to seeing the posties happy face on Wednesday

[Ratman407]

Next seimton

Pump the throttle 4-5 times she will start up and idle for maybe 5 seconds before dieing ??
Possible fuel pump failling ? Idk

[Ratman407]

Next seimton

Pump the throttle 4-5 times she will start up and idle for maybe 5 seconds before dieing ??
Possible fuel pump failling ? Idk

And on another note if I pump the throttle then discount the fuel line it does the same thing as when the fuel is connected
But the fuels still pumping because I put a jug on the line to make sure it was

[bumstein]

Yeah I’d expect if it were the fuel pump then it would fail under power.. I’m out of ideas unless you feel like cracking that thing open and checking the needle valve and float etc.

Pretty much I don’t think you’ve got a lot to lose between now and Wednesday, pull it apart and see what you can see? Disclaimer here, when you separate the cap from the float/throttle body there’s a spring/ball assy which pings if you’re not careful and it will end up FK where with little chance of knowing where it all came from in which order. I try find a pic which details the where and how

[Ratman407]

Yeah going shopping tomorrow but once I’m home I think I will crack it fully open or burn it to the ground both ideas sound good at this point

Really need to get the gti in my lounge room going so I have efi

[Ratman407]

What ever it is I can’t find it so have given up and will wait for the 4K to show

But I did work out how to over come it for now but I wouldn’t requmemd it it’s a very dodgy fix
I ended up adjusting the throttle cable so it will not fully shut and stays open enough to keep her idling at 2grand

[bumstein]

Oh well!! Temporary fix but if it gets you by until Wednesday