Becks Bear
Active Member
- Posts
- 258
- Location
- Northern Ireland
A brief history and sorry for the long winded story, but just wanted to inform as much as possible so i can find out what i did wrong
3.9efi non serp, no cats, with mark adams tuned ECU running green resistor.
The motor has been running good, yes has always been running rich
New dizzy rebuilt professionally less that 1000miles, new power amp at least two years old, checked still good spark. HT leads all new and good again about 2000 miles, engine oil and filters every 3000miles+/-
All injectors stripped, new filters and cleaned and bench tested maybe 600 miles ago all giving good spray pattern
So serviced the wagon yesterday as it was due
Oils and filters
Replaced the spark plugs NGKBP6ES 7811 which I always use and set gap 0.8mm
Old plugs removed where all black (but this due to her running rich and has always ran rich been trying to sort this for ever)
Removed K&N filter (it was old and I had no K&N cleaner left to service it) and replaced with standard new air filter
Replaced dizzy cap and rotor arm with a new Lucas
Firing order correct
Set base idle
Checked throttle pot, 0.35 volts
Checked MAF volts 1.5vdc
Checked fuel pressure 38psi (adjustable regulator so can always tweak this)
Removed and cleaned the stepper motor (not dirty when removed and it was replaced with a new one maybe three years back)
Checked the timing 10 degrees before TDC
Changed the engine coolant temp sensor (connected to the correct wiring loom, so fuel and coolant not crossed wired). The reason for changing, the one I fitted some time back I was not confidant it was good quality it was very cheap, the new replacement states its Lucas
Issues
After the service started the yoke and its back firing slightly and the smell of petrol fumes in the garage is worse than it’s ever been.
Test drove and the backfire is when I boot the throttle and she is also down on power.
So again rechecked all of the above, advanced the timing slightly and test drove again, slightly better power but still a slight backfire when accelerating and deaccelerating. Replaced the removed dizzy cap and drove again just the same.
Tested all on the rovergauge computer and no faults, tested the stepper motor with rovergauge opening and closing all ok, fuel pump working, spark at all plugs.
So the question is what did I do wrong as she never ever back fire before?????
Also the new spark plugs (from a reputable dealer and not cheap) look like ****e, the old ones removed are stamped as made in Japan, the new set have what looks like Russian writing on them.
I have taken pictures so can post if required
Any genuine suggestions or advice greatly welcome still working on it this morning so wish me luck
Cheers Ivan
3.9efi non serp, no cats, with mark adams tuned ECU running green resistor.
The motor has been running good, yes has always been running rich
New dizzy rebuilt professionally less that 1000miles, new power amp at least two years old, checked still good spark. HT leads all new and good again about 2000 miles, engine oil and filters every 3000miles+/-
All injectors stripped, new filters and cleaned and bench tested maybe 600 miles ago all giving good spray pattern
So serviced the wagon yesterday as it was due
Oils and filters
Replaced the spark plugs NGKBP6ES 7811 which I always use and set gap 0.8mm
Old plugs removed where all black (but this due to her running rich and has always ran rich been trying to sort this for ever)
Removed K&N filter (it was old and I had no K&N cleaner left to service it) and replaced with standard new air filter
Replaced dizzy cap and rotor arm with a new Lucas
Firing order correct
Set base idle
Checked throttle pot, 0.35 volts
Checked MAF volts 1.5vdc
Checked fuel pressure 38psi (adjustable regulator so can always tweak this)
Removed and cleaned the stepper motor (not dirty when removed and it was replaced with a new one maybe three years back)
Checked the timing 10 degrees before TDC
Changed the engine coolant temp sensor (connected to the correct wiring loom, so fuel and coolant not crossed wired). The reason for changing, the one I fitted some time back I was not confidant it was good quality it was very cheap, the new replacement states its Lucas
Issues
After the service started the yoke and its back firing slightly and the smell of petrol fumes in the garage is worse than it’s ever been.
Test drove and the backfire is when I boot the throttle and she is also down on power.
So again rechecked all of the above, advanced the timing slightly and test drove again, slightly better power but still a slight backfire when accelerating and deaccelerating. Replaced the removed dizzy cap and drove again just the same.
Tested all on the rovergauge computer and no faults, tested the stepper motor with rovergauge opening and closing all ok, fuel pump working, spark at all plugs.
So the question is what did I do wrong as she never ever back fire before?????
Also the new spark plugs (from a reputable dealer and not cheap) look like ****e, the old ones removed are stamped as made in Japan, the new set have what looks like Russian writing on them.
I have taken pictures so can post if required
Any genuine suggestions or advice greatly welcome still working on it this morning so wish me luck
Cheers Ivan