as per prev post, renewed all the sensors on the cossie, still wasnt right so changed the ignition amplifier on the inner wing and the coil, car started and ran perfect....better than it ever did! was well happy......until she got up to operating temperature and she runs like a bag of poo, like on three cylinders and obv wont boost properly and keeps cutting out! it will start again and run perfect for about ten seconds then go back to runnin like shit! Following has been replaced:

plugs, leads, coil, all engine bay sensors, ignition amp, fuel pump, fuel filter

any ideas?? its a 4x4 saff with a green top engine by the way - totally standard

 

Fuel pressure regulator? Idle CO set properly? Four teeth present on the crank pulley?

edit

scrap idle CO - it's green top and not adjustable. therefore - lambda sensor been replaced too?


oooh ooh - air leak? split vaccum hose?

I have a twincam Sierra that does exactly the same thing and I've never got to the bottom of it, despite replacing everything but the engine! WOuld love to find the answer to this one too

 

the easyiest way to see if its an air leak is to buy a can of carb cleaner. with the engine running spray around any pipes and inlet manifolds. the engine will revv faster as it draws in the vapour where the leak is.

the other obvious one is the fuel filter, a dirty and/or block fuel filter can make them run like a bag o shite, have a look under the spare wheel well, if its rusty - its not been replced in a good few years

 

Fuel filter is alloy so won't rust, and even when really old they can look as new.
Have you checked the dizzy shaft for wear/play sideways, there should be NONE.
Also have a close look at the CPS connector, try to do a wiggle test with it running, as in the process of replacing bits you may have disturbed a dodgy joint, CPS connector is a fave on cossies.
tabetha

 

alloy fuel filters still corrode but might be best replacing it anyway if it is an unknown age.
check the multi plugs on the bulkhead above the cam cover if it still has them for corrosion

 

well after replacing a nasty connector on one of the wires on the multi-plug of the ignition amplifier, the car fired up and ran perfectly for about 15 secs then went back to playin up.....wiggled the plug when it was running and it seemed to help so hoping its a loose connection. Ordered a new ignition amplifier but can i get a brand new multi-plug anywhere?

 

contact Ryan on here - the loom man himself, he will be able to supply a tailed multiplug for you to graft onto the end of your existing loom...

 

my mistake - i was thinking the sierra ones were the same as the escos ones - now they DO rust

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