[haurp00ned]

Heyy guys i have a 92 sierra with a 1.3l standard engine. and when it is running it attends to miss a lot and play up, I'm leaning towards the fact that i might need new spark plug and coil lead, or possibly a new coil or a new cap? any advise would be great thanks guys.

[primejo07]

Crap in your carby mate

[4x4xzook]

start with the simple things first. Are you letting it warm up before you drive it? could be the choke - does it come good after you drive it for a few minutes?? IF NOT.

1. check spark plugs are not burn out. - a new set should only cost you $20 odd dollars
while ur at it for another 20 u might as well change the leads too. also change the dizzi cap - something a lot of people forget to do!!

2. clean out the air filter, often mud and all sorts of yummy things can clogg it up causing the sierra to cough and fart.

3. suspected fuel issue if it is missing. is she fully topped up, does ur fuel gauge work? do you have a faulty fuel filter or pump maybe?

After you have done all this have a beer and congratulate urself on a mini service.. lol
if all of this does not work, then it may either be a timing issue or a number of things... can you describe what the car is doing, what rpm does it struggle? is it only on take off, between gears? - could be ur clutch??

[4x4xzook]

or as prime said ur carby.. try repco for some Carby cleaner.

just make sure u dont get any painted surfaces. haha

[haurp00ned]

I have checked all spark plugs and none are burnt, i cleaned my carbie with carbie cleaner, I'm buying a new fuel filter and maybe some new leads today.

And the Sierra it coughs and farts and plays up when idling, and in first gear until 3000rpm, and also the same in second but then after that it runs fine and smooth.

[primejo07]

do all the things 4x4xzook said, its the best way to narrow down whats causing the problem!

this is a write up oozuk did a few weeks ago and it fixed my carby i was having the exact same problem as you. its awesome help and it shows why auszookers is such a good community.

i also swapped leads 2 and 3 over with the carby hat off and got it backfiring a bit, it literally shoots the crap out of the carby.

oozuk wrote:

could be a couple of things.

A. the throttle plate bushes could be heavily worn (indicated by the fact when you rev it the rev's don't return to to the same before reving

B. Idle circuit could be blocked up try doing a poor mans tune up (follow steps below)

step 1: go to repco and buy a spray can of some good carby cleaner preferably one with a spray needle included (nulon one is good and smells pretty)
step 2: get the engine upto operating temp.
step 3: move the car off the nice concrete driveway as all sorts of shit will spray out of the tail pipe when doing this.
step 4: shut down the engine and use a 10mm spanner and remove the nut holding the intake off the top of the carby, unclip the airbox top and put it all to the side out of the way.
step 5: use some vice grips and remove the post from the center of the intake of the carby ( it unscrews)
step 6: look down the carby and identify the primary and secondary ports (primary has the choke butterfly in it and secondary has the little brass float breathers < REMEMBER THESE)
step 7: take your carby cleaner and using the spray needle insert it into one of the two float breathers in the top of the secondary ports and fill the bastard up until carby cleaner comes out the breathers, also whist your there spray it around in the primary and secondary ports whilst opening the choke with your fingers to get past the butterfly, you want to remove the varnish and see nice clean alloy inside these ports (now this is where it gets fun !!)
step 8: WITH THE ENGINE OFF !! reach down the back of the carby and pull it to Wide Open Throttle "WOT" and unflick the throttle cable off the throttle cam and bend it back out of the way so the carby can be controlled by hand (if this is not done and you rev it by hand it could possibly jam on WOT not fun pooing you pants whilst you rush to shut down your engine before things jump out of it)
step 9: get a friend to start the engine whilst you hold the throttle at 50%, Be prepared it will be hard to start and cough and splutter due to you flooding the carby with carby cleaner.
step 10: work the carby cleaner through the engine by reving the engine on and off the throttle. (now the cleaning starts)
step 11: with the engine running spray carby cleaner down the ports of the carby continue to hold the throttle open to sustain the engine revving.
step 12: not good if you have girly hands for this one!! after it has had a gutfull of carby cleaner you need to put it to work to do this directly after dumping a bit of carby cleaner down the ports of the carby (with the engine running) rev the living christ out of the engine to WOT say 5000-6000rpm (go by ear) then when it hits that point throw the palm of your hand over the carby to create a seal over the carby (still holding it WOT) effectively creating a massive vacumme in the carby and intake, and listen to the engine as the rev's die off to about 1500rpm (go by ear) let your hand off the carby and pump the throttle to keep the engine from dying.
step 13: continue steps 10-12 until happy, once done hold the engine at 1500rpm to allow the carby to clear itself and see if the idle improves (usually does if gummed up)

that may work for you it may not, at worst it costs you $12 for a can and some blisters on your hand (sounds like a night i had once)

don't be surprised if you go through a whole can of carby cleaner doing this

on another note... holy crap i think i've accually added "Tech" to auszookers !!!! what is this world coming to ?

[haurp00ned]

I have swapped the leads around with the carbie head off and made it back fire but no shit came out the carbie, the carbie seems clean and in all working order

[4x4xzook]

thats a sweet write up!!

see how it runs after u swap over the fuel filter!.. keep us posted.

[haurp00ned]

I re did the carbie cleaner and followed that wrote up. I then changed the fuel filter, and spark plugs and also dizzy cap, and now she's running good again, I also bough some spark plug leads and I'm just going to hang on to them as spares for now, thanks for all your guys help. Cheers.

[4x4xzook]

Good stuff. Now get out there and get it muddy!