Another emission problem
Discussion
Hi,
Another question for all of you very helpful people out there,
I had major problems starting my rover V8 engine after restoration which you all kindly helped with I then focused on the body repairs but coming back to the engine the saga continues,
Engine starts and runs but its running very rich, its a 1988 model EFI 3.5 emission should be 0.5-1 but I am running at high 3 to 4 CO. as seen in another thread my hydro carbons are also running high at around 2800-3000, adjusting the mixture screw on the flapper valve makes almost no difference to CO so I am guessing I am over fuelling also supported by black plugs, there is also a fair amount of smoke coming from the exhaust pipe although it not dark black its more black / white.
So far I have checked fuel pressure which is correct, engine compressions are all between 180-190 psi, ECU has been sent away and recalibrated, Air flow meter sent away recalibrated, new plugs BPR6ES, New distributor, new HT leads (just a note bought a set of new Lucas leads fitted them and when checking each cylinder for misfire I noticed tingling up my arm and I was using HT lead pliers for removing so they went!!) new coolant temp sender, cold start injector disconnected, new injector wiring harness, all breathers clear and no difference with rocker box breather pipe disconnected. Last weekend I tried a different ECU, a different air flow meter (actually ran worse with this one so it may of had a fault) different diode pack, all changes done one at a time and made no difference. The only thing that has not been changed are the injectors themselves unfortunately I cant see what's going on when the engine is running but I would have thought these were controlled by the ECU, I have removed the injectors and turned on ignition opened the flapper valve to check for leaking injectors but all was fine, the injectors will have to go away for servicing I think but any ideas you can throw at me would be of great help
Another question for all of you very helpful people out there,
I had major problems starting my rover V8 engine after restoration which you all kindly helped with I then focused on the body repairs but coming back to the engine the saga continues,
Engine starts and runs but its running very rich, its a 1988 model EFI 3.5 emission should be 0.5-1 but I am running at high 3 to 4 CO. as seen in another thread my hydro carbons are also running high at around 2800-3000, adjusting the mixture screw on the flapper valve makes almost no difference to CO so I am guessing I am over fuelling also supported by black plugs, there is also a fair amount of smoke coming from the exhaust pipe although it not dark black its more black / white.
So far I have checked fuel pressure which is correct, engine compressions are all between 180-190 psi, ECU has been sent away and recalibrated, Air flow meter sent away recalibrated, new plugs BPR6ES, New distributor, new HT leads (just a note bought a set of new Lucas leads fitted them and when checking each cylinder for misfire I noticed tingling up my arm and I was using HT lead pliers for removing so they went!!) new coolant temp sender, cold start injector disconnected, new injector wiring harness, all breathers clear and no difference with rocker box breather pipe disconnected. Last weekend I tried a different ECU, a different air flow meter (actually ran worse with this one so it may of had a fault) different diode pack, all changes done one at a time and made no difference. The only thing that has not been changed are the injectors themselves unfortunately I cant see what's going on when the engine is running but I would have thought these were controlled by the ECU, I have removed the injectors and turned on ignition opened the flapper valve to check for leaking injectors but all was fine, the injectors will have to go away for servicing I think but any ideas you can throw at me would be of great help
Two remarks:
- first my 350i always runs 3,5 CO% for the MOT and around 4,0% for the rest of the year...
- second not able to adjust CO at the flapper: take it fully out, clean it, put it back and adjust as you require.... Had this issue and was a great tip on here 10 years ago. Wasn't able to set/reduce CO and also idle adjustment . And all was solved in a couple of minutes.
Rob
- first my 350i always runs 3,5 CO% for the MOT and around 4,0% for the rest of the year...
- second not able to adjust CO at the flapper: take it fully out, clean it, put it back and adjust as you require.... Had this issue and was a great tip on here 10 years ago. Wasn't able to set/reduce CO and also idle adjustment . And all was solved in a couple of minutes.
Rob
jensencars said:
hi,
thanks no its set its delivering around 30 PSI as I recall it matched the spec
That is too high for idle...should be 23-26psi...and at wide open throttle (WOT) you need 36-38psi.thanks no its set its delivering around 30 PSI as I recall it matched the spec
If its a solid state one then could be a leaking diaphragm ..have you changed the air filter ...flame trap and checked the crank breather on the N/S rocker cover ..(The little mushroom)..to make sure it has a clear pinhole opening...to remove its best with a warm engine, as with the flame trap.
Hi,
Thanks all vents are new sorry forgot to say that,,flapper is clean as airflow meter has been reconditioned, it's definitely rich as plugs are black, I know they don't run lean but engine manual says .5 to 1 it's the sunburnt fuel that worries me more especially the mega HC's will try to get a substitute pressure reg to put on as mine is not adjustable
Thanks all vents are new sorry forgot to say that,,flapper is clean as airflow meter has been reconditioned, it's definitely rich as plugs are black, I know they don't run lean but engine manual says .5 to 1 it's the sunburnt fuel that worries me more especially the mega HC's will try to get a substitute pressure reg to put on as mine is not adjustable
Check the engine temperature sensor as that influences the AFM and if too high resistance when warm will encourage the AFM to open the injectors for longer.
Best to check the resistance at the ECU multiplug (in case the wiring is introducing resistance).
Good advice above to totally remove the AFM adjuster screw and blow down the hole to clean out accumulated crud.
Also check the mushroom breather pinhole is clear.
On my 350i I ran out of adjustment and had to add an extra bypass pipe (7mm dia squashes at one end) trapped under the outflow hose to admit a bit more air, for the MoT.
Best to check the resistance at the ECU multiplug (in case the wiring is introducing resistance).
Good advice above to totally remove the AFM adjuster screw and blow down the hole to clean out accumulated crud.
Also check the mushroom breather pinhole is clear.
On my 350i I ran out of adjustment and had to add an extra bypass pipe (7mm dia squashes at one end) trapped under the outflow hose to admit a bit more air, for the MoT.
If the AFM flapper has been reconditioned then its possible the base setting is wrong inside the flapper. Take off the plastic flat lid and mark the current position, pull the latch and move the round base plate a few notches and see if it improves or makes worse.. as it can be moved both ways.
Naturally there could be another issue and this should be sorted first.
Naturally there could be another issue and this should be sorted first.
Just a quick note - One notch adjustment on the AFM spring doesn't make that much difference so you may need to go a few notches to seen anything (Tipex time)
Can you get access to a wideband o2 meter ? I bought an Innovate LM2 50/50 with a mate and it paid for itself the first time I used it - if not the car would have suffered it's second engine failure due to being seriously lean at WOT.
Can you get access to a wideband o2 meter ? I bought an Innovate LM2 50/50 with a mate and it paid for itself the first time I used it - if not the car would have suffered it's second engine failure due to being seriously lean at WOT.
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