P38A Diesel Injector No.4

wammers · Jul 5, 2020

Reason it happens is when engine is subject to idle control throttle pot below 9% and idle switch engaged. ECU controls idle speed to 750 + or - 50 RPM. So if engine is idling at 750 and load is applied to it, the CPS detected RPM will reduce, so ECU causes quantity servo to give more fuel to maintain 750 RPM. When load is reduced and CPS detects a change in RPM the ECU will cause quantity servo to reduce fuel to maintain 750 RPM. So basically only a very small portion of the position or feedback track is being used, therefore it wears exponentially to the rest of the track causing loss of contact in that small area.

Lukas018 · Jul 5, 2020

wammers said:
Reason it happens is when engine is subject to idle control throttle pot below 9% and idle switch engaged. ECU controls idle speed to 750 + or - 50 RPM. So if engine is idling at 750 and load is applied to it, the CPS detected RPM will reduce, so ECU causes quantity servo to give more fuel to maintain 750 RPM. When load is reduced and CPS detects a change in RPM the ECU will cause quantity servo to reduce fuel to maintain 750 RPM. So basically only a very small portion of the position or feedback track is being used, therefore it wears exponentially to the rest of the track causing loss of contact in that small area.

Ok great I see now. Yeah mil lamp when need more power not when dropping down or at idle.

wammers · Jul 5, 2020

Lukas018 said:
Ok great I see now. Yeah mil lamp when need more power not when dropping down or at idle.

Don't think you read that right.

Lukas018 · Jul 5, 2020

wammers said:
Don't think you read that right.

When I drive mine the lamp/injector light flashes when engine needs more power in changing gear and has symptoms you mentioned earlier. It is the only time it occurs. I had this symptom way before I changed the chains so. I either have 2 duff pumps with the same fault or there was an inherent fault all along that is not making the pump function correctly. Hence why I need to run a nanacom see what's going on as @Datatek suggest before got getting new pumps and that.

Datatek · Jul 5, 2020

Lukas018 said:
Ok great I see now. Yeah mil lamp when need more power not when dropping down or at idle.

So you just get the MIL lamp when you boot it? Not on lift off when the revs drop?
Have you ever checked the connector to the EDC for corrosion?

wammers · Jul 5, 2020

Lukas018 said:
When I drive mine the lamp/injector light flashes when engine needs more power in changing gear and has symptoms you mentioned earlier. It is the only time it occurs. I had this symptom way before I changed the chains so. I either have 2 duff pumps with the same fault or there was an inherent fault all along that is not making the pump function correctly. Hence why I need to run a nanacom see what's going on as @Datatek suggest before got getting new pumps and that.

Ok carry on I have explained it to, it is when the throttle is released and the throttle pot drops below idle position. If it is very slight it flashes the MIL lamp as it worsens at idle speed the engine stops.

Lukas018 · Jul 5, 2020

Datatek said:
So you just get the MIL lamp when you boot it? Not on lift off when the revs drop?
Have you ever checked the connector to the EDC for corrosion?

Yea that's what I get whenever I accelerate the lamp flashes and no when the revs drop. Have checked and cleaned the connections and few times.

Datatek · Jul 5, 2020

Lukas018 said:
Yea that's what I get whenever I accelerate the lamp flashes and no when the revs drop. Have checked and cleaned the connections and few times.

So, I think that you cannot progress without diagnostics and a check on the modulation

Lukas018 · Jul 5, 2020

Datatek said:
So, I think that you cannot progress without diagnostics and a check on the modulation

Yes I agree so my issue is now getting a nanacom

Lukas018 · Jul 5, 2020

wammers said:
Ok carry on I have explained it to, it is when the throttle is released and the throttle pot drops below idle position. If it is very slight it flashes the MIL lamp as it worsens at idle speed the engine stops.

I have listened just telling you what I am experiencing. Can't go further without a nanacom so that's my next task and advise from there on.

Datatek · Jul 5, 2020

Lukas018 said:
I have listened just telling you what I am experiencing. Can't go further without a nanacom so that's my next task and advise from there on.

I don't think Wammers has read what you have written exactly, he's missed the fact that it's not to do with dropping to idle.

Lukas018 · Jul 5, 2020

Datatek said:
I don't think Wammers has read what you have written exactly, he's missed the fact that it's not to do with dropping to idle.

Just been out to it again and now when I rev it does the opposite when revs drop light flashes and there is a delay between pushing the throttle and engine response.

It wasnt doing that before at all.

Need to diagnostics only forward really to make sense what's happening.

Datatek · Jul 5, 2020

Lukas018 said:
Just been out to it again and now when I rev it does the opposite when revs drop light flashes and there is a delay between pushing the throttle and engine response.

It wasnt doing that before at all.

Need to diagnostics only forward really to make sense what's happening.

If it flashes the MIL light on revs dropping you might be back to Wammers worn quantity servo.

RangeRoller dt · Jul 5, 2020

136 Is normally QS as far as I’m aware and that last description does wreak of it.

Datatek · Jul 5, 2020

RangeRoller dt said:
136 Is normally QS as far as I’m aware and that last description does wreak of it.

136 is normally QS? Waht is 136? If it's a fault code, on what device??

Lukas018 · Jul 5, 2020

Datatek said:
136 is normally QS? Waht is 136? If it's a fault code, on what device??

136 is fuel actuator circuits which relates to QS on the hawkeye diagnostic.

It is intermittent aswell and engine does not stall but clear fault and comes back.

I will try and do nanacom diagnostics to be sure.

If it is FIP then I have been well and truly stuffed.

Datatek · Jul 5, 2020

Lukas018 said:
136 is fuel actuator circuits which relates to QS on the hawkeye diagnostic.

It is intermittent aswell and engine does not stall but clear fault and comes back.

I will try and do nanacom diagnostics to be sure.

If it is FIP then I have been well and truly stuffed.

What diagnostic tool is that from?
I'm sorry to say that you have no chance of a refund from Skit, I know I have tried.

Lukas018 · Jul 5, 2020

Datatek said:
What diagnostic tool is that from?

Hawkeye from Bearmach.

Datatek · Jul 5, 2020

Lukas018 said:
Hawkeye from Bearmach.

OK, I have no knowledge of that unit so I do not know in detail what the code really means, I might have a search to see what can be found.

Lukas018 · Jul 5, 2020

Datatek said:
OK, I have no knowledge of that unit so I do not know in detail what the code really means, I might have a search to see what can be found.

Have attached photo of it doesn't give much by way of information.

P38A Diesel Injector No.4

No longer with us, RIP

Well-Known Member

No longer with us, RIP

Well-Known Member

Well-Known Member

No longer with us, RIP

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Sprung Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Attachments

Similar threads