al-one-arm

Well-Known Member

• Nov 21, 2012

• #1

hi all
all the time that i have had my 1995 4.0 se petrol (single point lpg, never used) its warm tick over has been 700 rpm in park and 550 rpm in gear, my indy garage say that they cannot alter the tickover by laptop.
just recently, however, it sometimes stalls, usually on a left hand slow corner,
if i turn the steering whilst in park, at standstill, the revs can drop to 600rpm.
any ideas?
alan

 

al-one-arm

Well-Known Member

• Nov 23, 2012

• #2

its now cut out after a nice burst of speed.not nice with no steering and a roundabout ahead.
at tickover, in park, i tried revving it to see if i could get it to cut out on overrun.
initially the revs dropped then picked up, then backfired then cutout, it took about 3mins after to get it to restart

 

Saint.V8

Dyed-in-the-wool 100% RR Junkie

Full Member

• Nov 23, 2012

• #3

Possibley the Idle Air Control Valve is a bit sticky....

 

al-one-arm

Well-Known Member

• Nov 26, 2012

• #4

which one is the" idle air control valve " on the intake?
where is the "c.t.s." (coolant temperature sensor)?
can i take all of the bits off the air input side and clean them, with carb cleaner, without having to have it all reset with laptop?

 

al-one-arm

Well-Known Member

• Dec 22, 2012

• #5

took it to my indy, they put in the laptop.the only fault listed, said that crankshaft was out of sync with camshaft?
it had not done it since , till tonight, typical, when all garages are going to be closed for days,
where is the crankshaft position sensor?

 

Saint.V8

Dyed-in-the-wool 100% RR Junkie

Full Member

• Dec 23, 2012

• #6

al-one-arm said:

took it to my indy, they put in the laptop.the only fault listed, said that crankshaft was out of sync with camshaft?
it had not done it since , till tonight, typical, when all garages are going to be closed for days,
where is the crankshaft position sensor?

Click to expand...

IIRC it is on the back of the engine by the bell housing I think...

RAVE is your friend!

 

kevwill

Active Member

• Dec 23, 2012

• #7

Saint.V8 said:

IIRC it is on the back of the engine by the bell housing I think...

RAVE is your friend!

Click to expand...

On passenger side. Check the wiring connections first.

 

al-one-arm

Well-Known Member

• Dec 24, 2012

• #8

further update:
every time that it has gone wrong, is just after restarting it when hot, ie drive from cold runs perfect, get it upto temperature, perfect, stop the engine to say fill up with petrol, try to restart, winds over for a while before starting, then drive off, couple of hickups like it misses the smooth gear change , then sometimes cuts out, sometimes wont rev, stop the engine, leave it till its cold, starts and runs perfect again.

 

Datatek

Well-Known Member

• Dec 24, 2012

• #9

al-one-arm said:

further update:
every time that it has gone wrong, is just after restarting it when hot, ie drive from cold runs perfect, get it upto temperature, perfect, stop the engine to say fill up with petrol, try to restart, winds over for a while before starting, then drive off, couple of hickups like it misses the smooth gear change , then sometimes cuts out, sometimes wont rev, stop the engine, leave it till its cold, starts and runs perfect again.

Click to expand...

I know nowt about the V8 but that could well be a crank sensor. The only way to be sure would be diagnostics using live data or a scope.

 

al-one-arm

Well-Known Member

• Dec 24, 2012

• #10

seeing as it does all short journeys ,its never had any injector cleaner added, so, ive just put 2 bottles of injector cleaner in, lets see if that makes any differance

 

E

eightinavee

Well-Known Member

• Dec 24, 2012

• #11

This shows all the symptoms of a failing crank sensor,they do tend to break down when hot.The engine ecu does not really have any chance to log crank sensor faults,but it does expect the signal to remain in synch with the cam sensor.
After checking the cable is not chafed there are two options;
1,Scope the crank and cam signals as the engine warms up - you should see the signal deteriorate as the engine gets hot or be very feeble when hot starting.
2, Just replace the crank sensor with a new or known good one if a scope is not available to test.
With Gems engines its also a good idea to remove the 1/2 moon plate that covers the lower front part of the flywheel behind the sump.They are prone to the U shaped tangs being damaged - which are what the crank sensor tip sits in to read the 36-1 pattern.Any damage must be repaired to avoid confusing the ecu.