engine fault - not sure which direction to take
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engine fault - not sure which direction to take
hi there,
ive reached the point where im not sure what to do. i have a rover 3.9l efi in a cobra replica. Been having problems with it for a while now and cant work out what is wrong. It has recently returned from a garage after having a load of tests done but nothing untoward found. these are the tests that were done:
Fuel supply/return pipes - nff
Fuel pressure/pressure regulator operation - nff (36psi min)
fuel condition i.e.: water ingress - nff
fuel rail/injector leak test (initially thought to have failed upon removing and retesting turned out to be a fault with the pressure gauge) - nff
fuel injector pattern/flow test.- ok (they haven't been duty cycled)
Ignition timing - static/idle & maximum mechanical advance. - nff (10*idle, 30* full advance)
ECU/engine earth points cleaned secured..- ok
ECU coolant thermistor operation/multi plug condition.- nff
Injector electrical pulse (noid) test.- nff
Throttle potentiometer operation - nff
Engine compression test - ok (c150psi)
ignition system - rotor/cap/leads/plugs.- nff
Air flow meter operation/adjustment. T.B.C
Visual inspection of engine wiring loom (where accessible). - nff
Check for inlet air leaks (where accessible) - nff
Now, the main reason for sending the car to the garage was becuase the engine sounded like it was mis-firing and was running rich as there was popping and banging at all revs and a lot of black oil particles coming out of one of the exhaust pipes - the injectors had been sent off separately about a year ago and these were all tested, refurbished and refitted - do they jam easily if left unused?
Does anyone have any idea where to go from here, the gargage was listing the following as next course of action but i was reluctant as i hoped a specific avenue would have been found to go down rather than testing everything:
removal and testing of all injectors to include duty cycle
removal/inspection/replace inlet manifold gasket
inspect cam shaft & valve gear.
Remove dashboard to access ECU, remove multiplug and 'pin out' engine harness
Test ECU
the car has been sitting for years due to the above but before that was running beautifully for a long time. Any help greatly received
ive reached the point where im not sure what to do. i have a rover 3.9l efi in a cobra replica. Been having problems with it for a while now and cant work out what is wrong. It has recently returned from a garage after having a load of tests done but nothing untoward found. these are the tests that were done:
Fuel supply/return pipes - nff
Fuel pressure/pressure regulator operation - nff (36psi min)
fuel condition i.e.: water ingress - nff
fuel rail/injector leak test (initially thought to have failed upon removing and retesting turned out to be a fault with the pressure gauge) - nff
fuel injector pattern/flow test.- ok (they haven't been duty cycled)
Ignition timing - static/idle & maximum mechanical advance. - nff (10*idle, 30* full advance)
ECU/engine earth points cleaned secured..- ok
ECU coolant thermistor operation/multi plug condition.- nff
Injector electrical pulse (noid) test.- nff
Throttle potentiometer operation - nff
Engine compression test - ok (c150psi)
ignition system - rotor/cap/leads/plugs.- nff
Air flow meter operation/adjustment. T.B.C
Visual inspection of engine wiring loom (where accessible). - nff
Check for inlet air leaks (where accessible) - nff
Now, the main reason for sending the car to the garage was becuase the engine sounded like it was mis-firing and was running rich as there was popping and banging at all revs and a lot of black oil particles coming out of one of the exhaust pipes - the injectors had been sent off separately about a year ago and these were all tested, refurbished and refitted - do they jam easily if left unused?
Does anyone have any idea where to go from here, the gargage was listing the following as next course of action but i was reluctant as i hoped a specific avenue would have been found to go down rather than testing everything:
removal and testing of all injectors to include duty cycle
removal/inspection/replace inlet manifold gasket
inspect cam shaft & valve gear.
Remove dashboard to access ECU, remove multiplug and 'pin out' engine harness
Test ECU
the car has been sitting for years due to the above but before that was running beautifully for a long time. Any help greatly received
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- Newbie
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- Joined: Wed Mar 16, 2011 1:32 pm
CTS is the coolant temperature sensor. If this fails open circuit (the most likely way) the ECU will think the engine cold and go maximum rich.
Easily checked at home with a DVM.
The cold start injector isn't controlled by the ECU. No need to unplug it as it only operates below a certain temperature. The engine will start on all but the coldest day without it, though.
Sounds like the system wants a thorough check through. Sadly, very few garages understand it well.
Easily checked at home with a DVM.
The cold start injector isn't controlled by the ECU. No need to unplug it as it only operates below a certain temperature. The engine will start on all but the coldest day without it, though.
Sounds like the system wants a thorough check through. Sadly, very few garages understand it well.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
- Ian Anderson
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- Location: Edinburgh
Check your spark plugs.
Are all electrodes similar colour? If not the different one is showing the problem cylinder
Are they all the same brand and heat range? If so what?
Wait till dark
Open bonnet
Start car, look at wiring for spark show, to see if spark is escaping before plug.
Would be my first test
Ian
Are all electrodes similar colour? If not the different one is showing the problem cylinder
Are they all the same brand and heat range? If so what?
Wait till dark
Open bonnet
Start car, look at wiring for spark show, to see if spark is escaping before plug.
Would be my first test
Ian
Owner of an "On the Road" GT40 Replica by DAX powered by 3.9Hotwre Efi, worked over by DJ Motors. EFi Working but still does some kangaroo at low revs (Damn the speed limits) In to paint shop 18/03/08.
- Ian Anderson
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http://www.cowdery.org.uk/downloads/FlapperManual.zip is the Land Rover manual.
http://www.cowdery.org.uk/downloads/V8EFiSystem.pdf is a TVR interpretation of the same.
Chris.
http://www.cowdery.org.uk/downloads/V8EFiSystem.pdf is a TVR interpretation of the same.
Chris.
--
Series IIA 4.6 V8
R/R P38 4.6 V8
R/R L405 4.4 SDV8
Series IIA 4.6 V8
R/R P38 4.6 V8
R/R L405 4.4 SDV8
- Ian Anderson
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So the problem is you perceive it is running rich....but you also state oil and black particles coming from one exhaust pipe only ?
Is that one exhaust per bank, or other ?
And is it actually running rich ? What sort of mixtures is it seeing ? Hydrocarbons ? Again, for each bank if possible.
And does this correspond with injector pulse widths for each bank ? ie are they excessively high ?
Injectors can give issues if laid up for a long time, but it really depends what the last fluid was through them and how they were stored.
But you dont seem to be suggesting it is off cylinders as per a stuck injector.
Is that one exhaust per bank, or other ?
And is it actually running rich ? What sort of mixtures is it seeing ? Hydrocarbons ? Again, for each bank if possible.
And does this correspond with injector pulse widths for each bank ? ie are they excessively high ?
Injectors can give issues if laid up for a long time, but it really depends what the last fluid was through them and how they were stored.
But you dont seem to be suggesting it is off cylinders as per a stuck injector.