FrankXK8
RMS Regular
- Messages
- 113
- Drives
- XKR
Hi folks
Having real trouble with idle on my 1993 RRC, are there any experts in the Rover V8 in NI ? Thinking perhaps TVR people would know...
The car is a 1993 Range Rover with the 3.9 V8, catalyst-equipped and 14CUX “hotwire” electronics.
The problem is that the emissions are poor (high CO (1.5%) and extremely high HC (3240) readings.
The idle is lumpy, very up and down. The car accelerates and cruises very well, but idles badly and will stall when coming to a stop in Drive or Reverse. Always restarts with no issue.
1. New AIR Filter, spark plugs,
2. New coil, plug leads, distributor cap, distributor rotor, Denso spark plugs
3. New Lucas idle control valve, MAF and O2 sensors
4. New coolant temperature sensor (CTS)
5. Oil change, coolant change
6. Checked all vacuum tubes, and flex tube between MAF and plenum, replaced the T-piece in the breather assembly
7. Cleaned flame-trap and the breather.
8. Clamped off the idle control valve pipe – idle unaffected, is still up and down.
9. Disconnected the MAF connector – idle unaffected, is still up and down.
10. New fuel-pressure-regulator
11. Even put new/reconditioned injectors in, thinking the old ones might have been drippy
12. Tried a new MAF (ebay cheapie) - no difference, so refitted the old original
12. Sprayed carb cleaner around the plenum, injectors, vacuum hoses, joins – no effect.
There are no fault codes showing up in Rovergauge diagnostics. All of the sensors old and new are showing up okay in Rovergauge (Transmission PNPS, road speed sensor, fuel temperature sensor). It is not catalyst-related as there are no sensors after the cars, only before.
A log was gathered during a test drive, the stall event can be seen around lines 937 in the log.
But I think the key fact is that the car is running rich, and the short-term-fuel-trim is like -90% (therefore the ECU sees that it is rich, so is decreasing the injector time)
Running out of skills and ideas now, so will have to find someone with the brains and experience ! The car failed its MOT due to emissions. Based in Downpatrick.
Cheers
Frank
Having real trouble with idle on my 1993 RRC, are there any experts in the Rover V8 in NI ? Thinking perhaps TVR people would know...
The car is a 1993 Range Rover with the 3.9 V8, catalyst-equipped and 14CUX “hotwire” electronics.
The problem is that the emissions are poor (high CO (1.5%) and extremely high HC (3240) readings.
The idle is lumpy, very up and down. The car accelerates and cruises very well, but idles badly and will stall when coming to a stop in Drive or Reverse. Always restarts with no issue.
1. New AIR Filter, spark plugs,
2. New coil, plug leads, distributor cap, distributor rotor, Denso spark plugs
3. New Lucas idle control valve, MAF and O2 sensors
4. New coolant temperature sensor (CTS)
5. Oil change, coolant change
6. Checked all vacuum tubes, and flex tube between MAF and plenum, replaced the T-piece in the breather assembly
7. Cleaned flame-trap and the breather.
8. Clamped off the idle control valve pipe – idle unaffected, is still up and down.
9. Disconnected the MAF connector – idle unaffected, is still up and down.
10. New fuel-pressure-regulator
11. Even put new/reconditioned injectors in, thinking the old ones might have been drippy
12. Tried a new MAF (ebay cheapie) - no difference, so refitted the old original
12. Sprayed carb cleaner around the plenum, injectors, vacuum hoses, joins – no effect.
There are no fault codes showing up in Rovergauge diagnostics. All of the sensors old and new are showing up okay in Rovergauge (Transmission PNPS, road speed sensor, fuel temperature sensor). It is not catalyst-related as there are no sensors after the cars, only before.
A log was gathered during a test drive, the stall event can be seen around lines 937 in the log.
But I think the key fact is that the car is running rich, and the short-term-fuel-trim is like -90% (therefore the ECU sees that it is rich, so is decreasing the injector time)
Running out of skills and ideas now, so will have to find someone with the brains and experience ! The car failed its MOT due to emissions. Based in Downpatrick.
Cheers
Frank
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