GQ Revving high. Please help!

[jayj23]

Howdy guys,

Long story short I started my GQ up this morning it was a little hesitant, I gave it a little throttle and all of a sudden it started to rev and maintain at about 2500rpm. It will not drop and I can't figure out why.

Does anyone have any ideas?

1990 TB42
SWB Maverick

Thanks in advance

[Bloodyaussie]

Hmmm?? Fuel position sensor playing up??? that one you can adjust your self.

Cable is in good condition??

[threedogs]

Is it on gas? Try and release the throttle cable by hand, heaps of CRC.

[rusty_nail]

i am also having this problem and would be keen to hear if anyone has a fix for it?

[patch697]

This cold be a symptom of a few things.

First thing I'd be checking is throttle cable including the hand throttle, carby linkages & return spring.

If this all checks out ok then get back to us & we can then target other arias that maybe of concern.

[taslucas]

Auto choke may be staying on. Try a real quick short sharp stab of the accelerator.
As said above, the throttle cable may be sticking, (with engine off)try moving it by hand at the carby end and try to get crc/wd40/penetrene into it.
The linkages on the carb may be sticking, (with engine off)spray everything with crc etc and try to wiggle/move by hand paying special attention to the rubber boots and vacuum switches.
Try some carby clean down the carby (with air filter off and engine running).

Tap, crackle, pop

[rusty_nail]

ok, i i had a look at mine the other day. my car specs are in signature. the throttle lever thing is not sticking, i adjusted the idler thing on the carby(black round thing that you can increase and decrease idle speed) and the idle on petty has turned down however running on LPG the idle is very high(2-2.5k RPM) does this indicate a vaccum leak as lucas has suggested? any ideas on how to pinpoint vaccum leaks?

[taslucas]

Hmmm, I don't know how to check for a vacuum leak, I was.just suggesting to make sure the switch is moving freely.


Tap, crackle, pop

[rusty_nail]

well in my case, everything is moving freely.

[taslucas]

Tried a bit of carby clean down the throat? (the cars not yours!).
Do the butterflies close off completely when throttle is backed off?

Tap, crackle, pop

[healy]

Does the car still run properly when driving Or is it losing power?

[rusty_nail]

i dont know how to check that. not sure if my car even has that. i have an impco 300 vaccum on mine with a completely different filter setup etc. the car runs with plenty of power still its just hard to drive at it won go down from such high revs. is the butterfly the point where the air is taken into the carby?

[threedogs]

Vacuum hoses perish or become brittle, just replace them very cheap.
Sometimes running on gas the system will lean out causing very very high temps.
sometimes this will melt the carbie causing the molten metal to lodge under the butterfly.
Visual inspection is your friend here. Personally I'd be spraying WD40 or similar on all
linkages hopefully this will free it up. Plus replace the hoses

[patch697]

ok, i i had a look at mine the other day. my car specs are in signature. the throttle lever thing is not sticking, i adjusted the idler thing on the carby(black round thing that you can increase and decrease idle speed) and the idle on petty has turned down however running on LPG the idle is very high(2-2.5k RPM) does this indicate a vaccum leak as lucas has suggested? any ideas on how to pinpoint vaccum leaks?

One way to check is to grab yourself a can of WD, CrC, RP7 something like that & with the engine running spry around all your hoses, joins running off your inlet manifold, the manifold gaskets themselves, break & clutch booster connections/vacuum hoses & if the sound of the engine changes at all or a particular spot you have sprayed dries out very quickly then there is a better than good chance your found a vacuum leak.

[taslucas]

If there's a vacuum leak in a hose for lpg then you would be down on power and it wouldn't want to rev out.
The vacuum leak I was talking about was in a vacuum switch, making it not work properly and maybe making the choke stay on.
When you look straight down the throat of the carby, the butterflies are the metal circles attached to the accelerator shaft that open and close when the shaft is turned as you accelerate.

Tap, crackle, pop

[rusty_nail]

If there's a vacuum leak in a hose for lpg then you would be down on power and it wouldn't want to rev out.
The vacuum leak I was talking about was in a vacuum switch, making it not work properly and maybe making the choke stay on.
When you look straight down the throat of the carby, the butterflies are the metal circles attached to the accelerator shaft that open and close when the shaft is turned as you accelerate.

Tap, crackle, pop

sounds like a job for tongiht over a few beers.cheers for all the infor guys

[threedogs]

You have some great info there to suss out over a few beers, keep us updated.

[Morton]

doesnt sound like a sticking auto choke, the revs are to high, auto chokes are usually set between 1000-1500 rpm, 2500 rpm would indicate something else, at the back of the carby is a yellowish half moom plastic disc, this is part of the auto choke, turn it up or down & you will notice a change in the revs, which ever way it lowers the revs push it harder, it will move if it is stuck

[threedogs]

Hey Rusty do you have an up date for us ???

[Irish]

Not saying this is 100% the issue, but you never know.

Pull off your airbox and look down inside your carb. See if there is what looks like a large washer blocking your secondary butterfly from closing.

If there is, push the "washer" back across towards the primary(towards the right front wheel) for a quick temp fix. Then when you get a chance, pull the carb off, You'll see a weird looking bit of metal that looks like it directs the a/f mixture into the intake manifold. It's supposed to be completelyround at the top but it wears on the sides. I had the same issue the other day, fixed it back in place with some liquid gasket and put everything back together, running fine now.

This is what the metal doovilacky looks like: http://i121.photobucket.com/albums/o234/Irishpete/IMAG0706.jpg

(Note the areas of wear)

[Irish]

So did you figure out what it was??????