B18E Fenix 1 engine running problems. Suggestions welcome!
Posted: Fri Oct 23, 2015 3:57 pm
I am looking for some help to get my '87 ES running sweetly. It has the very first Fenix 1 system (i.e. PTC, black bodied sensors).
I don't think there are any vacuum leaks and I have replaced the Idle Air Control Valve with a new one as I thought that could have been the problem. As far as the ignition system is concerned, it has had plugs leads, distributor, rotor arm in the past year or so with no improvement in running.
Sometimes, it idles well, other times, especially when hot, it will idle very high (2000rpm). Blipping the throttle can persuade it to come down, sometimes. Sometimes, I can drag it down and it will stay down, by trying to stall it with the clutch. Most of the time nothing helps!
It can be juddery in power application up to 3000rpm, but when cold, often isn't.
Over, 3000rpm it consistently runs beautifully. The power delivery is smooth and it sounds sweet! It is an absolute pleasure to drive on the motorway, just a bit crap once you have to slow down.
To me this points to the coolant temperature sensor as I have heard that above 3000rpm it is basically ignored by the Fenix as it cares more about air pressure at this point. I'm sure I read that on here somewhere. Does this sound true?
If I unplug the temperature sensor (spark plug 1 location, hidden under the Idle Control Valve, the revs change, implying to me that it is at least connected.
My next course of action will be to set the throttle position sensor so that at least I will know if the Idle Air Control valve is being told to bypass at the correct times.
After that, I will adjust the CO potentiometer with the Pulsair system blanked.
That is where I'm stumped. I seem to have misplaced my book with instructions on how to do that, in fact I think I gave it away with the '88 ES as I didn't think I would get another B18E. I adjusted the TPS on a B18E with Fenix 3.2 (I think) 5 years ago, so it is just a distant memory.
On the photo above:
What are 1 and 2? Is one of them the NRV for the Pulsair system? (also!!! Is Pulsair the same as EGR or am I getting confused?
2 is on the end of the fuel rail, but does it actually have anything to do with fuel or is it just mounted there.
Disconnecting 2 causes the RPM to rise, when the manifold is blanked with a finger, they return to normal. Is that the Pulsair blanked then?
Where does 3 go? The engine dies when it is disconnected. I think it feeds the VEM pneumatic valves, if I recall correctly from when I investigated them years ago. Where else does it go? It must do more than that if the engine cuts out!
On the photo above:
I disconnected the CO potentiometer and it had no effect on the engine running. I assume it must be open circuit. I will ring this out to the pins at the ECU.
Disconnections while engine running:
1. Temp sensor: revs change
2. CO potentiometer: no effect
3. IAC: revs change
4. Vacuum pipe and T-piece at "2" on first picture: revs rise (as expected), then return to normal when blanked with fingers.
5. Haven't touched pipe "1" on first picture
6. Pipe "3" on first picture: engine stops when disconnected.
So, there are about a million questions above. To recap:
1. What are 1, 2 and 3 and where do they go?
2. Is Pulsair the same as EGR?
3. How and where do I blank Pulsair/EGR for CO potentiometer adjustment?
4. Am I right or wrong about Fenix 1 basically ignoring coolant temperature above 3000 rpm?
What does anyone think of my next steps?
1. Adjust TPS
2. Check wiring between CO potentiometer and Fenix.
3. Adjust CO to 1% (on garage MOT machine) with Pulsair blanked
4. Check wiring between coolant temperature sensor and Fenix. Check resistance of sensor (should be 290 Ohms at 20 deg. C..
5.
I'd really appreciate people's input as I am running out of talent, but ambition is high!
I don't think there are any vacuum leaks and I have replaced the Idle Air Control Valve with a new one as I thought that could have been the problem. As far as the ignition system is concerned, it has had plugs leads, distributor, rotor arm in the past year or so with no improvement in running.
Sometimes, it idles well, other times, especially when hot, it will idle very high (2000rpm). Blipping the throttle can persuade it to come down, sometimes. Sometimes, I can drag it down and it will stay down, by trying to stall it with the clutch. Most of the time nothing helps!
It can be juddery in power application up to 3000rpm, but when cold, often isn't.
Over, 3000rpm it consistently runs beautifully. The power delivery is smooth and it sounds sweet! It is an absolute pleasure to drive on the motorway, just a bit crap once you have to slow down.
To me this points to the coolant temperature sensor as I have heard that above 3000rpm it is basically ignored by the Fenix as it cares more about air pressure at this point. I'm sure I read that on here somewhere. Does this sound true?
If I unplug the temperature sensor (spark plug 1 location, hidden under the Idle Control Valve, the revs change, implying to me that it is at least connected.
My next course of action will be to set the throttle position sensor so that at least I will know if the Idle Air Control valve is being told to bypass at the correct times.
After that, I will adjust the CO potentiometer with the Pulsair system blanked.
That is where I'm stumped. I seem to have misplaced my book with instructions on how to do that, in fact I think I gave it away with the '88 ES as I didn't think I would get another B18E. I adjusted the TPS on a B18E with Fenix 3.2 (I think) 5 years ago, so it is just a distant memory.
On the photo above:
What are 1 and 2? Is one of them the NRV for the Pulsair system? (also!!! Is Pulsair the same as EGR or am I getting confused?
2 is on the end of the fuel rail, but does it actually have anything to do with fuel or is it just mounted there.
Disconnecting 2 causes the RPM to rise, when the manifold is blanked with a finger, they return to normal. Is that the Pulsair blanked then?
Where does 3 go? The engine dies when it is disconnected. I think it feeds the VEM pneumatic valves, if I recall correctly from when I investigated them years ago. Where else does it go? It must do more than that if the engine cuts out!
On the photo above:
I disconnected the CO potentiometer and it had no effect on the engine running. I assume it must be open circuit. I will ring this out to the pins at the ECU.
Disconnections while engine running:
1. Temp sensor: revs change
2. CO potentiometer: no effect
3. IAC: revs change
4. Vacuum pipe and T-piece at "2" on first picture: revs rise (as expected), then return to normal when blanked with fingers.
5. Haven't touched pipe "1" on first picture
6. Pipe "3" on first picture: engine stops when disconnected.
So, there are about a million questions above. To recap:
1. What are 1, 2 and 3 and where do they go?
2. Is Pulsair the same as EGR?
3. How and where do I blank Pulsair/EGR for CO potentiometer adjustment?
4. Am I right or wrong about Fenix 1 basically ignoring coolant temperature above 3000 rpm?
What does anyone think of my next steps?
1. Adjust TPS
2. Check wiring between CO potentiometer and Fenix.
3. Adjust CO to 1% (on garage MOT machine) with Pulsair blanked
4. Check wiring between coolant temperature sensor and Fenix. Check resistance of sensor (should be 290 Ohms at 20 deg. C..
5.
I'd really appreciate people's input as I am running out of talent, but ambition is high!