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oakrichardson

New Member

• Apr 14, 2012

• #1

Hi,

my 3.9 v8 efi from a 96 disco takes a very long time to start, and will usualy not go from cold until it has oil pressure (about 8 seconds of cranking) and then i switch on the fuel pump or it floods and it will go. It runs good when going though. any ideas?

 

jamesmartin

Well-Known Member

• Apr 14, 2012

• #2

does it tap to start with

 

landowner

Pensioner Pete

Full Member

• Apr 14, 2012

• #3

Plugs and sparks, timing may be retarded

 

discool

Well-Known Member

• Apr 15, 2012

• #4

Thats is a bit excessive, you do have to crank the 3.9s a bit more when cold, mine takes about four or five revs to wake up the ecu and pump not a great problem as it's just two seconds and we are running.

I would also go for "Plugs and sparks, timing may be retarded" whos plugs and what grade are u using?.

There is no interface between the oil pressure and the starter so if you were able to start running in a couple of seconds or so the oil pressure will be there, unless you have a pump problem that is..

 

vougese39

Well-Known Member

• Apr 15, 2012

• #5

Why are you switching the pump on?
Is it on gas?
Are they gen ignition parts?
Has the ecu been tested for duff sensors?

 

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oakrichardson

New Member

• Apr 18, 2012

• #6

hi,

when first starting i can only get it to run with good oil pressure, and until then i dont switch on the fuel pump as it will flood. it is not on gas, ignition components have come from a dealer so i would expect them to be genuine.

The ecu has not been tested, i believe the plugs are ngk but will have to check. The timing has not been set as this is the first few times i have started it, but will get that done asap.

 

jamesmartin

Well-Known Member

• Apr 18, 2012

• #7

the only way oil pressure would effect starting is if tappets were draining overnight etc ,and valves wernt opening fully ,good timing (use a strobe ) plugs, leads,dizzy cap .rotor arm ,amplifier and coil are needed for good starting and running. check temp sensor for ecu on lhs front of inlet manifold it should increase fuel for cold starts

 

discool

Well-Known Member

• Apr 18, 2012

• #8

Rich mixture on startup can be caused by the air control valve (stepper motor) sticking and therefore not fully open. You should be able to hear it returning to it's fully open position when the ignition is turn off, if you don't then remove it and clean it.

 

Playsatan13

New Member

• Aug 10, 2012

• #9

i had a prob with mine taking ages to crank, turned out i was only running on 6 cylinders.
2 HT leads were buggered
does it backfire if you flood it?