[Buick] VR V6 in VNs1, teething troubles

[savage1987]

have changed over entire ignition system. coil packs and DFI replaced, plugs and leads replaced with new

also changed the MAP for good measure

still splutters

worse now, does it free revving too

 

[savage1987]

A vacuum leak ---possible
A bad spark plug wire ---don't think so, replaced all plugs and leads with new
A thermostat stuck open ---nope, near new and perfectly installed. heats up fine at idle and stays where it's meant to
A leaking fuel injector ---hope not
A defective oxygen sensor ---possible but was fine 3wks ago
A loose or corroded engine ground ---have checked all i can find
A carbon-coated air intake temperature sensor ---impossible. clean as a whistle inside the manifold
A defective manifold absolute pressure sensor ---replaced, did not fix
A defective engine coolant temperature sensor ---possible

.................

 

[delcowizzid]

no fuel leaking out the reg vacuam hose.you may have got a dodgy plug making it worse.did you gap the plugs to 1.5mm.got fuel going past the reg back to the tank.correct injectors are they new and are the orings sealing in the manifold.did the last engine fill the cat with fluids.got an ALDL cable and laptop .

 

[delcowizzid]

were the plugs all sooty when you took them out

 

[savage1987]

no fuel leaking out the reg vacuam hose. --none you may have got a dodgy plug making it worse.did you gap the plugs to 1.5mm. --i have never gapped a set of plugs in my life got fuel going past the reg back to the tank --must do, fuel system primed fine when we primed all the air out of it for first startup could hear it squirting air into the tank.correct injectors are they new and are the orings sealing in the manifold. --stock VR V6 injectors not new, no spray / fuel leaking upward so o rings must be good. did the last engine fill the cat with fluids. --no got an ALDL cable and laptop --no

will go pull plugs now, swapping TPS changed nothing

getting a VN stock memcal to try, see if less timing and more fuel makes a difference

 

[delcowizzid]

the injector orings too the manifold i meant they will suck air in there no petrol will escape

 

[savage1987]

ah ok not sure how to test that. they should be good tho, no probs fitting them

 

[delcowizzid]

spray engine start round them to check for leaks if the revs change theres a leak

 

[savage1987]

righto. shame, carby cleaner is all i have... it'll ruin my paint work

 

[delcowizzid]

got a butane torch you can do the same thing with butane/lpg just dont light it obviously and way the nozzle past the inlet seals and around the injector boses throttlebody join and elbow join