The injectors are pulsed from the main PCM, I think Robbie did a good write up on how they are controlled.
Flack
5th Nov 2020 9:40 am
Motolab
Member Since: 18 Oct 2019
Location: Sleen
Posts: 1815
Yupp, so readings wil not be 12V (or constant whatever voltage) on most voltage readers, because it is on.off/on/off/etc.. readers can not be that fast...Best regards
Harold
Always looking for Pre '55's & Pre war British Motorcycles! knowing or having one for sale? PM please. I visit the UK 6 times a year
Ps. I edit my texts quite often, english is not my native language, so I will edit My “typo’s” etc.
5th Nov 2020 10:00 am
rrhool
Member Since: 28 Aug 2014
Location: Norfolk
Posts: 4400
Depends where you read the voltage. The injectors cold be +12V with a switched earth.Richard
D3 SE 2007. Triumph 2.5Pi 1973. Ferguson TEA20 1948.
Discovery 2 4.0 ES 2001- Gone
Discovery 1 300Tdi ES '95 - Gone
Range Rover Classic '79 - Gone
5th Nov 2020 10:21 am
Farmer joe
Member Since: 10 Sep 2020
Location: Dungannon
Posts: 46
gstuart wrote:
Hiya
Pretty sure u should have 12 volts on the injectors , maybe bad connection between the injectors and ECM
Is ur main battery standing Vdc ok and have u had the codes read yet plse
Also included a wiring diagram Hope that helps
Click image to enlarge
Yes battery is good, got codes read, it just showed something to do with MAF, they were cleared and never came back. Thanks for the diagram.
5th Nov 2020 10:44 am
Farmer joe
Member Since: 10 Sep 2020
Location: Dungannon
Posts: 46
Motolab wrote:
Not meant to be rude, but farmer joe is shooting with hail now..
Get your codes read, as said earlyer topics, all about the same engine not running...
Seems impossible to me that injectors have a constant voltage... if so they are constantly open or constantly closed and that would not work
I prefer a IID, LR specific but some people have results with cheapy’s from ' arround 50 quid or arround..
I’m not being rude either, I thought that’s what this forum is for, asking questions. I have only posted one other topic about it not starting.
I have got the codes read and it’s just for MAF, it was cleared and didn’t show again.
As gstuart said and I also thought, the injectors should have a constant 12v feed and a negative feed from ecu to pulse the injectors, it is that negative feed that would open and close the injectors.
5th Nov 2020 11:02 am
Farmer joe
Member Since: 10 Sep 2020
Location: Dungannon
Posts: 46
rrhool wrote:
Depends where you read the voltage. The injectors cold be +12V with a switched earth.
I read the voltage from the connector at the injectors.
5th Nov 2020 11:06 am
Motolab
Member Since: 18 Oct 2019
Location: Sleen
Posts: 1815
i presume MAF error only comes back, when your engine runs, but it does not run, so error is not comming back... maybe?
change the MAF... (or clean it to start with) NOT by poking IN the hole!)
since you bought another engine... you have maybe two MAF sensors? you could try..Best regards
Harold
Always looking for Pre '55's & Pre war British Motorcycles! knowing or having one for sale? PM please. I visit the UK 6 times a year
Ps. I edit my texts quite often, english is not my native language, so I will edit My “typo’s” etc.
5th Nov 2020 11:07 am
Motolab
Member Since: 18 Oct 2019
Location: Sleen
Posts: 1815
Farmer joe wrote:
I’m not being rude either, I thought that’s what this forum is for, asking questions.
sure! just want to help.. what i meant is that if you need help with the non starting issue, it is easyer for us to get the "whole" picture
and since "we" do not know (untill your (just) last answer in this new topic) what and if you did read the codes, (it was not answered or mentioned until now) i did not get the whole picture..
your earlyer/other topic regarding the same non starting issue was this one is it not?
Always looking for Pre '55's & Pre war British Motorcycles! knowing or having one for sale? PM please. I visit the UK 6 times a year
Ps. I edit my texts quite often, english is not my native language, so I will edit My “typo’s” etc.
5th Nov 2020 11:16 am
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 13657
Motolab wrote:
Yupp, so readings wil not be 12V (or constant whatever voltage) on most voltage readers, because it is on.off/on/off/etc.. readers can not be that fast...
Hiya
May i ask , Would u then need to use an oscilloscope to test the injectors if a multimeter is too slow to respond to the pulsing voltages plse
Many thks
5th Nov 2020 11:42 am
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 13657
Farmer joe wrote:
gstuart wrote:
Hiya
Pretty sure u should have 12 volts on the injectors , maybe bad connection between the injectors and ECM
Is ur main battery standing Vdc ok and have u had the codes read yet plse
Also included a wiring diagram Hope that helps
Click image to enlarge
Yes battery is good, got codes read, it just showed something to do with MAF, they were cleared and never came back. Thanks for the diagram.
Hiya , ur so welcome
Also wonder if u can test the resistance of the injector coils , have been trying to find what the ohms should be but alas haven’t found that as of yet
Also found this from the workshop manual
There are six electronic fuel injectors (one for each cylinder) located in a central position between the four valves of each cylinder.
The ECM divides the injectors into two banks of three with cylinders 1 to 3 being designated bank A and cylinders 4 to 6 designated bank B, with injector numbers 1 and 4 at the front of the engine. Although the injectors are numbered 1-6 the firing order determined by the ECM software is numbered 0-5.
Each injector is supplied with pressurised fuel from the fuel rail and delivers finely atomised fuel directly into the combustion chambers. Each injector is individually controlled by the ECM which operates each injector in the firing order and controls the injector opening period via PWM signals. Each injector receives a 12V supply from the ECM and, using programmed injection/timing maps and sensor signals, determines the precise pilot and main injector timing for each cylinder.
If battery voltage falls to between 6 and 9V, fuel injector operation is restricted, affecting emissions, engine speed range and idle speed. In the event of a failure of a fuel injector, the following symptoms may be observed:
The ECM monitors the wires for each injector for short circuit and open circuit, each injector and the transient current within the ECM. If a defect is found, an error is registered in the ECM for the injector in question
5th Nov 2020 11:49 am
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 13657
Out of curiosity would something like be helpful, know the members here are considerably more knowledgeable than myself , or is it just the case u wish to test the ecm side
Plus can u use a noid test light to see if a signal feed is there
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