Volvo Community Forum. The Forums of the Volvo Owners Club

Forum Rules Volvo Owners Club About VOC Volvo Gallery Links Volvo History Volvo Press
Go Back   Volvo Owners Club Forum > "Technical Topics" > 700/900 Series General

Notices

700/900 Series General Forum for the Volvo 740, 760, 780, 940, 960 & S/V90 cars

Information
  • VOC Members: There is no login facility using your VOC membership number or the details from page 3 of the club magazine. You need to register in the normal way
  • AOL Customers: Make sure you check the 'Remember me' check box otherwise the AOL system may log you out during the session. This is a known issue with AOL.
  • AOL, Yahoo and Plus.net users. Forum owners such as us are finding that AOL, Yahoo and Plus.net are blocking a lot of email generated from forums. This may mean your registration activation and other emails will not get to you, or they may appear in your spam mailbox

Thread Informations

B230ET Motronic Testing v B23ET - Haynes

Views : 3662

Replies : 21

Users Viewing This Thread :  

Reply
 
Thread Tools Display Modes
Old Jan 22nd, 2007, 07:32   #1
765-Turbo-1989
Junior Member
 

Last Online: Dec 17th, 2012 12:43
Join Date: Mar 2006
Location: Norwich
Default B230ET Motronic Testing v B23ET - Haynes

The purpose of this thread is to share experience testing the Motronic system (electrical side, not fuel side) on a B230ET using the Haynes instructions for the B23ET which is 'believed to be similar'.
All according to my Haynes Volvo 740 and 760 (petrol) 1982-1989 Owners Workshop Manual dated 1993 ISBN 1 85010540 5. The spine of the book is numbered 1258.

Testing Procedure Electrical side (page 155)

See www.autoelectric.ru/auto/volvo/740/1989/740-89.htm for the correct wiring diagram and location of all the components and connectors etc.

Item 4, No earth continuity on pin 16 or 17. There is however earth continuity on pin 6, but only when the ECU is plugged in to the harness.

Item 15 does not apply. No Air Conditioning Advance Relay on B230ET.

Items 16 and 17 do not apply as there is a separate 'Power Stage, Motronic' which is specifically for the Fuel injectors.
This is NOT to be confused with the separate 'Ignition amplifier' on the B230FT and mentioned liberally in the FAQ. On the B230ET this amplifier is integrated in to the ECU itself so don't go looking for it.

I have not tested the Fuel injector resistances but it appears straightforward from the web site information above.

There is additionally the ' Radio Interference Supression Relay'
765-Turbo-1989 is offline   Reply With Quote
Old Oct 20th, 2010, 15:00   #2
AncientTurbo
New Member
 

Last Online: Nov 8th, 2010 17:33
Join Date: Oct 2010
Location: Tetbury
Default Still no spark

Hi, thank you for the comments on the differences between the 230ET and 230FT control boxes - I was looking for the Ignition Control Box! I've been working outwards from the non-sparking plugs and am happy with the coil - the distributor and rotor arm - and the TDC/rotation output. But there my knowledge and testing have hit a brick wall. I have run all the 'Haynes' tests (from page 157/158) and they seem OK. What I can't resolve is which of those tests actually prove the ignition amplification that pushes a decent VAC through to the coil primary wiring - which clearly I am not getting. One flow chart I have followed says that the Power Stage is the culprit. But the Power Stage in our cars seems only to cover the fuel injectors? Just wondered if you had any thoughts?
AncientTurbo is offline   Reply With Quote
Old Oct 20th, 2010, 17:57   #3
765-Turbo-1989
Junior Member
 

Last Online: Dec 17th, 2012 12:43
Join Date: Mar 2006
Location: Norwich
Default

Quote:
Originally Posted by AncientTurbo View Post
Hi, thank you for the comments on the differences between the 230ET and 230FT control boxes - I was looking for the Ignition Control Box! I've been working outwards from the non-sparking plugs and am happy with the coil - the distributor and rotor arm - and the TDC/rotation output. But there my knowledge and testing have hit a brick wall. I have run all the 'Haynes' tests (from page 157/158) and they seem OK. What I can't resolve is which of those tests actually prove the ignition amplification that pushes a decent VAC through to the coil primary wiring - which clearly I am not getting. One flow chart I have followed says that the Power Stage is the culprit. But the Power Stage in our cars seems only to cover the fuel injectors? Just wondered if you had any thoughts?
You say nothing about the LV side.
The Radio Suppression relay on the 760 Turbo is also in circuit for the ignition although not shown on the Haynes diagram as that is for the 740. It is under the bonnet on nearside on my car and identical to the electic fan relay if you have air conditioning so they can be swapped for testing.

In addition the Motronic relay is in circuit, on the main relay board inside the car.
Then there is the ECU itself which contains a built in power amplification stage. I bought a second hand one to test with on a swap out basis.

If those are all working ok and there is no wiring problem, you should be getting the corect LV feed to the coil as far as I know.
765-Turbo-1989 is offline   Reply With Quote
Old May 22nd, 2019, 15:57   #4
rogerthechorister
Rogerthechorister
 

Last Online: Dec 16th, 2023 03:15
Join Date: May 2006
Location: Rochester
Default Hot days!

I realise that this is the resurrection of ancient history but maybe somebody can help me with an intermittent fault on my Motronic B230ET 760T. On very hot days, when slow moving (sticky traffic) she will splutter and die. She also worryingly did it on a not very hot day recently just as emerging (slowly) from the Rotherhithe tunnel. Leave her 20 minutes and she will run perfectly - and if kept above 35 mph continue to run perfectly.

I had a similar fault on one of my B230FT 940 Sports, and that turned out to be the crank position sensor. New despite some experts saying that the Motronics did NOT have a CPS, my garage changed the CPS and it has not effected a cure.

Others said "ignition amplifier, needs fresh thermal paste" - which is why Mr Google led me here - but from this thread it seems that I have not got an ignition amplifier - save for the power stage for the injectors. Can anybody pls post a picture of the power stage so I can find it, and check that it has proper heat dissipation?

Another possibility might be overheating of the coil - possibly to be cured by new coil and thermal paste in the securing strap.

A third possibility could be fuel vaporisation, but what could have changed to affect that?

I do NOT want to have to replace the ECU, so I hope it will not be that. And it's one of the parts I have not got a spare for!

Of course a fault that only crops up once or twice a year is a real bathmat to find.

What does the team think?
__________________
B234F estate, H reg 100k miles. RIP melted B280E.
760T estate, F reg 133k miles.
940 Sport M90 estate, N reg 170k miles.
940 Sport M90 estate, N reg 100k miles, ex Lovejoy.
960 Estate, N reg, 56k miles, blown up and sold.
rogerthechorister is offline   Reply With Quote
Old May 22nd, 2019, 16:27   #5
360beast
Go redblock or go home
 
360beast's Avatar
 

Last Online: Today 22:08
Join Date: Feb 2012
Location: UK
Default

Isn't the powerstage the black box in the engine bay in front of the N/S strut tower? Been a few years since I looked at Motronic as I'm yet to fit the ET in to my 360.

Fuel vapourisation could be caused because fuel has gone to a 15% ethanol content.
360beast is online now   Reply With Quote
Old May 22nd, 2019, 18:53   #6
rogerthechorister
Rogerthechorister
 

Last Online: Dec 16th, 2023 03:15
Join Date: May 2006
Location: Rochester
Default Ethanol

Ah, interesting. Which has more ethanol, super or ordinary? And how to treat that if it were to be the problem? Try to wiggle a further heatshield in by the fuel rail?
__________________
B234F estate, H reg 100k miles. RIP melted B280E.
760T estate, F reg 133k miles.
940 Sport M90 estate, N reg 170k miles.
940 Sport M90 estate, N reg 100k miles, ex Lovejoy.
960 Estate, N reg, 56k miles, blown up and sold.
rogerthechorister is offline   Reply With Quote
Old May 22nd, 2019, 19:39   #7
360beast
Go redblock or go home
 
360beast's Avatar
 

Last Online: Today 22:08
Join Date: Feb 2012
Location: UK
Default

I'm not sure which has more, I don't think they would have a different Ethanol content to be honest as it would be the petrol part that is different and I think it is law now that petrol has 15% ethanol.

I know the cars at work old 1950's and 60's Bentleys have an overflow pipe in the fuel system, once it has got to temp and you turn the car off the ethanol carries on bubbling away as it has a lower boiling point and drips out of the overflow pipe. So yeah I have ethanol dripping on me daily haha.
360beast is online now   Reply With Quote
The Following User Says Thank You to 360beast For This Useful Post:
Old May 23rd, 2019, 16:22   #8
rogerthechorister
Rogerthechorister
 

Last Online: Dec 16th, 2023 03:15
Join Date: May 2006
Location: Rochester
Default Found the power stage

I've found the power stage. But I can't get it out to see how it is heatsinked and how to remove old thermal paste and insert new paste. 10mm headed bolt on top easily removed - but it's still solid. It mounts to a bracket with a bolt to the inner wing and a nut onto a stud on the wheel tub - I MIGHT be able to get at them if I took the battery out. There is a big plug on one edge and that looks as if it should spin out upwards - but with the amount of force I have used so far it does not budge...
__________________
B234F estate, H reg 100k miles. RIP melted B280E.
760T estate, F reg 133k miles.
940 Sport M90 estate, N reg 170k miles.
940 Sport M90 estate, N reg 100k miles, ex Lovejoy.
960 Estate, N reg, 56k miles, blown up and sold.
rogerthechorister is offline   Reply With Quote
The Following User Says Thank You to rogerthechorister For This Useful Post:
Old May 23rd, 2019, 23:20   #9
Laird Scooby
Premier Member
 
Laird Scooby's Avatar
 

Last Online: Today 21:57
Join Date: May 2012
Location: Lakenheath
Default

Quote:
Originally Posted by rogerthechorister View Post
I've found the power stage. But I can't get it out to see how it is heatsinked and how to remove old thermal paste and insert new paste. 10mm headed bolt on top easily removed - but it's still solid. It mounts to a bracket with a bolt to the inner wing and a nut onto a stud on the wheel tub - I MIGHT be able to get at them if I took the battery out. There is a big plug on one edge and that looks as if it should spin out upwards - but with the amount of force I have used so far it does not budge...
From your description of the location, it sounds suspiciously liek the injector resistor pack on the inside wing. Should be able to check it with a multimeter on resistance to see if it's failed.

Any pics so i can say yes, it is the resistor pack or no, not seen one those before?
__________________
Cheers
Dave

Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........
Laird Scooby is online now   Reply With Quote
The Following User Says Thank You to Laird Scooby For This Useful Post:
Old May 24th, 2019, 07:24   #10
360beast
Go redblock or go home
 
360beast's Avatar
 

Last Online: Today 22:08
Join Date: Feb 2012
Location: UK
Default

It looks the same as on a 940 Dave, it has some wires going in to cylindrical looking objects all joined together in a small metal cage.

https://www.ebay.co.uk/itm/Volvo-940...-/401642493511
360beast is online now   Reply With Quote
The Following User Says Thank You to 360beast For This Useful Post:
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 22:28.


Powered by vBulletin
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.