|
700/900 Series General Forum for the Volvo 740, 760, 780, 940, 960 & S/V90 cars |
Information |
|
Post lockdown problemViews : 1744 Replies : 27Users Viewing This Thread : |
|
Thread Tools | Display Modes |
May 29th, 2020, 15:48 | #1 |
940 LPT Est/V70XC AWD
Last Online: Mar 23rd, 2024 13:25
Join Date: Dec 2003
Location: Waterlooville
|
Post lockdown problem
Hi everyone, my ancient 940 2.3 LPT (97 MY) has been sitting idle for these past month(s).
Started it yesterday and whilst it started on the button, it's only running on 3 cylinders! Natch, it was running fine before lockdown. Pulled leads and it's #1 that's doing nothing. Checked for spark - yes, good spark. I pulled the injector plugs on #1 and #2 and tested for voltage on the 2 pins with ignition on. #1 showing 11.98V on one and 0.48V on t'other. #2 is showing 11.98V on both. So from that I assume something is amiss but I have no experience on Fuel Injection and am a bit unsure how to proceed now. Any suggestions, please? Thanks. Andy |
The Following User Says Thank You to clandyuk For This Useful Post: |
May 29th, 2020, 17:22 | #2 |
Premier Member
Last Online: Apr 9th, 2024 21:44
Join Date: Jul 2009
Location: Holywood
|
The fuel ECU pulls the ground side down to zero to actuate the injector, the 12V is permanent (via the radio supression fuel relay).
All the injector leads are connected in paralell, they should all show identical voltages, and should both show close to 12V if you have at least 1 injector coil still attached. Seems you have a faulty loom. |
The Following 2 Users Say Thank You to TonyS9 For This Useful Post: |
May 29th, 2020, 17:41 | #3 |
940 Noob
Last Online: Yesterday 20:48
Join Date: Jul 2015
Location: Birmingham
|
Swap the injectors about, you might have a blocked injector. It's a bit of a messy job, especially if the fuel rail is still pressurised (release the pressure using the valve found at the bottom of the fuel rail). You could also check the resistance of each injector. Assuming you have the original 0 280 150 804 injectors, resistance should between 2-3 ohms per injector.
If you're going to remove the injectors, it would be worth flashing a torch into the tops of them to see if the filter basket looks clogged.
__________________
96 945 Classic 2.3 LPT with some mods... To do: Install upper brace, Catch can, install sound deadening (50% done), Fit electric leather seats, repaint! List is endless... 16 BMW 330e Last edited by Chooch84; May 29th, 2020 at 17:46. |
The Following 2 Users Say Thank You to Chooch84 For This Useful Post: |
May 29th, 2020, 18:25 | #4 | |
940 LPT Est/V70XC AWD
Last Online: Mar 23rd, 2024 13:25
Join Date: Dec 2003
Location: Waterlooville
|
Quote:
I left the linngs out and then had to suffer clouds of steam from water evaporating on the bonnet when it rained and I was stopped in traffic. Will investigate with a torch. He/She might be back as a result of the lockdown. Just to clarify - should both injector plug wires show the same Voltage when grounding them via the Voltmeter or at least the same Voltages for each separate lead wire IYSWIM? |
|
The Following 2 Users Say Thank You to clandyuk For This Useful Post: |
May 29th, 2020, 18:29 | #5 |
940 LPT Est/V70XC AWD
Last Online: Mar 23rd, 2024 13:25
Join Date: Dec 2003
Location: Waterlooville
|
|
The Following 2 Users Say Thank You to clandyuk For This Useful Post: |
May 29th, 2020, 22:30 | #6 | |
Premier Member
Last Online: Today 12:22
Join Date: May 2012
Location: Lakenheath
|
Quote:
Start it up and see if it's back on all 4 pots. If so, there's either dirt on the connector inside the injector plug on the one with the low reading or a break in the cable. It will help you narrow down the problem more quickly anyway.
__________________
Cheers Dave Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........ |
|
The Following 3 Users Say Thank You to Laird Scooby For This Useful Post: |
May 29th, 2020, 23:17 | #7 | |
940 LPT Est/V70XC AWD
Last Online: Mar 23rd, 2024 13:25
Join Date: Dec 2003
Location: Waterlooville
|
Quote:
Thank you. |
|
The Following 2 Users Say Thank You to clandyuk For This Useful Post: |
May 29th, 2020, 23:59 | #8 |
Premier Member
Last Online: Today 12:22
Join Date: May 2012
Location: Lakenheath
|
You're welcome, hopefully it gives a few ponters as to where the problem lies.
__________________
Cheers Dave Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........ |
The Following User Says Thank You to Laird Scooby For This Useful Post: |
May 30th, 2020, 02:30 | #9 | |
Premier Member
Last Online: Apr 9th, 2024 21:44
Join Date: Jul 2009
Location: Holywood
|
Quote:
So with multimeter in voltage mode between chassis ground and either injector pin it should show both as near 12V. An injector just like an open ended coil with 12V at one side. The other side will also be at 12V also because there is no current runing though it. (Vdrop=IR) If you unplug all the injectors you will see 12V only one 1 pin of the connector, the other side I'm not sure what it will be at because it connected to an open collector output of a power electronic stage in the ECU, it could be at any voltage when its not trying to actuate the injector. |
|
The Following 2 Users Say Thank You to TonyS9 For This Useful Post: |
May 30th, 2020, 12:53 | #10 | |
Premier Member
Last Online: Today 12:22
Join Date: May 2012
Location: Lakenheath
|
Quote:
The +12V will be on the pin with the green wire on the injector plug.
__________________
Cheers Dave Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........ |
|
The Following User Says Thank You to Laird Scooby For This Useful Post: |
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
|
|