Outer Limits 4x4 Board

iv got a 1989 sierra nt

when i picked the car up around 2 weeks ago
it was running fine

the problem iv got is when i put my foot on the accelerator it goes for a bit then cuts out then goes and cuts out and so on
untill im in higher revs

it seems to do it alot more when the engine is cold

but also does it when its warm

pissing me off really embarrassing driving it around haha

thought i would ask you guys before taking it to a merchanic
thanks guys

When mine does that i flush the radiator. There is a little allen key thingo under your carby. Undo that for about 2Litres do it back up fill the rad and give it another go... Mine is odd like that but

Josh

fuel filter - which is located infront of the back wheel on the inside of the chassie on the drivers side. Remove the 2 clips and see if you can blow threw it, if its really hard get a new one for about $10

If you have just picked it up here's what I would do to get it up to scratch no matter what the prevous owner told you about its service history etc:

• replace:
  
  fuel filter
  spark plugs
  leads
  Air filter
  oil filter
  engine, gearbox, transmission and diff oils
  distributor and rotor button - replace if looking tired
  mechanical fuel pump - these seem to be going on most sierras around 20 years old
  then get yourself a timing light and set the timing, should have little sticker on inside of bonnet telling you the standard timing

that's what i would do at a minimum. Sounds to me like fuel starvation, like MrRocky said could be bockage in fuel filter but is also most likely the diaphragm in the mechanical fuel pump on the engine destroying itself. this does a couple of things. It will release little bits of crud into your carby which can affect performance and it will also release raw fuel into your head as well...not good by any means.

good luck

Mine occasionally does that which im suspecting is the fuel filter as well, it looks like it hasn't been changed since the car was built... got a new one waiting to be put on.

Replace all vacuum hoses. Had the same trouble, a small hose about 8cm long that had become real hard was jumping off the manifold giving poor idle. Can buy it at repco $4 a metre.

thanks for the help guys

hi mate just had the same problem with mine
it was verry simple to fix this is what i reccomend

it is defonatly fule related so like everyone has been saying check the fule filter also undo the banjo fitting on the front of the carby and crank the engine while this is off if there is only a little trickle of fule it means you need to replace the fule pump whitch is no big job, i replaced those 2 things on mine and it worked perfectly but i also gave it a carby clean and new plugs whitch is a good idear.

with the fuel filter. get two supercheap generics for $3 each. they are a tad smaller than the stock ryco one (which was like $20 last time i checked)

put one in stock location the other between the fuel pump and the carb. then replace it every 6-12months by throwing out the stock location one, moving the carb one to the back and putting ]the new one between the pump and carb (or jujst replace both)

the ryco one only lasted me 2 yearss (but to be fair i use ethanol blends and it was chocked with 13yrs of crud that had dislodged from my tank)

the other tricks are
-revving it by hand then blocking the intake the huge vacuum draws extra fuel to flush the jets

- poring a steady pencil-thick stream of water down the carb whilst keeping the engine alive by manually operating the throttle. dont let it die! this literally cleans the carbon deposits inside your engine, valves, pistons, combustion chamber the lot, dont be alarmed if your engine spits out heaps of white smoke and soggy black flecks (oil change immediately after procedure is recommended)

-clean the gunk thats accumilated in the hose between the crank case vent, pcv valve and airbox