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

Help!?

Views : 1563

Replies : 29

Users Viewing This Thread :  

Reply
 
Thread Tools Display Modes
Old Oct 27th, 2020, 22:50   #21
Laird Scooby
Premier Member
 
Laird Scooby's Avatar
 

Last Online: Today 13:32
Join Date: May 2012
Location: Lakenheath
Default

Quote:
Originally Posted by B10B View Post
All the bins are available on Jetronic Wiki.
Thanks for the heads-up on the existence of that site! Found the site and also found the information i've been trying to remember and/or find to refresh my memory for a while now.

All of that just for an extra 3 deg advance!
__________________
Cheers
Dave

Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........
Laird Scooby is offline   Reply With Quote
The Following User Says Thank You to Laird Scooby For This Useful Post:
Old Oct 27th, 2020, 23:18   #22
B10B
Bald
 
B10B's Avatar
 

Last Online: Aug 10th, 2023 20:15
Join Date: Jun 2010
Location: Ipswich
Default

Quote:
Originally Posted by Laird Scooby View Post
All of that just for an extra 3 deg advance!
Yes it's quite funny, more so when you consider the EZK reverts to the map at WOT negating any bridging of the pins anyway!

I know this as I tried retarding 3 degs to cure some knock only to find it didn't,
Once I got the chippable EZK and made a map using the 148 bin reducing it by the same 3 degs problem solved.
B10B is offline   Reply With Quote
The Following User Says Thank You to B10B For This Useful Post:
Old Oct 27th, 2020, 23:33   #23
Laird Scooby
Premier Member
 
Laird Scooby's Avatar
 

Last Online: Today 13:32
Join Date: May 2012
Location: Lakenheath
Default

Quote:
Originally Posted by B10B View Post
Yes it's quite funny, more so when you consider the EZK reverts to the map at WOT negating any bridging of the pins anyway!

I know this as I tried retarding 3 degs to cure some knock only to find it didn't,
Once I got the chippable EZK and made a map using the 148 bin reducing it by the same 3 degs problem solved.
I assume it reverts to the standard map to protect the engine under WOT then? There is another way round it on n/asp cars and that's disconnect the WOT connection at the TPS, i guess on turbo'd cars that facility isn't available.

The reason i'm after 3 deg advance is also the reason why the WOT reversion won't matter too much, firstly i always run Super Unleaded and secondly (the main reason) i'm converting to LPG so the extra 3 deg will improve the economy and make it a bit livelier too.
The general plan is a DPST relay to link pins 18 & 19 to 0V when the LPG is on, that way i can use one pole of the relay contacts per pin so they are only linked when the relay is operational.

Meanwhile i'll see if adding the 3 deg advance improves the economy.

It's a lot easier on my other beast, the engine management is designed to automatically advance the timing until it detects knock then retards it slightly so it's always running at optimum advance.
__________________
Cheers
Dave

Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........
Laird Scooby is offline   Reply With Quote
The Following User Says Thank You to Laird Scooby For This Useful Post:
Old Oct 27th, 2020, 23:49   #24
B10B
Bald
 
B10B's Avatar
 

Last Online: Aug 10th, 2023 20:15
Join Date: Jun 2010
Location: Ipswich
Default

The turbo cars have the same TPS, problem is taking it out of the loop means the ECU doesn't know when to resume idle fuel which causes over-fueling and a high idle, the WOT connection is used for fuel enrichment, on turbos at least.
It's unknown as to why they resort to the standard map but protection would be my best guess too.
It's also worth noting that having the pins grounded with a switchable toggle or relay to change modes so to speak, will cause problems if you do it with the motor running.
You would have to choose what 'mode' you wanted based on what fuel you are running on each time before you turn the key.
Lighter loads should work and in practice you should see small gains in economy.

Last edited by B10B; Oct 28th, 2020 at 00:26.
B10B is offline   Reply With Quote
The Following User Says Thank You to B10B For This Useful Post:
Old Oct 28th, 2020, 00:55   #25
Laird Scooby
Premier Member
 
Laird Scooby's Avatar
 

Last Online: Today 13:32
Join Date: May 2012
Location: Lakenheath
Default

Quote:
Originally Posted by B10B View Post
The turbo cars have the same TPS, problem is taking it out of the loop means the ECU doesn't know when to resume idle fuel which causes over-fueling and a high idle, the WOT connection is used for fuel enrichment, on turbos at least.
It's unknown as to why they resort to the standard map but protection would be my best guess too.
It's also worth noting that having the pins grounded with a switchable toggle or relay to change modes so to speak, will cause problems if you do it with the motor running.
You would have to choose what 'mode' you wanted based on what fuel you are running on each time before you turn the key.
Lighter loads should work and in practice you should see small gains in economy.
Hmmm, i was always led to believe there was no connection to the WOT switch on turbo cars.

Interested as to why you think switching "modes" as it were with the engine running will cause problems? Should certainly be possible to leave the pins grounded permanently given that not only do i run 98RON unleaded normally but also at present have a very basic but working water injection system that will also boost the octane rating somewhat.

I'm guessing here that the inputs on those two pins and the 4 different settings that selects are fed an electronic switch/logic gate rather than controlling things directly so the map would then alter at the next available opportunity.

However, it's all software controlled and software is not my strong point so i'm no help on that score.
__________________
Cheers
Dave

Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........
Laird Scooby is offline   Reply With Quote
The Following User Says Thank You to Laird Scooby For This Useful Post:
Old Oct 28th, 2020, 20:22   #26
B10B
Bald
 
B10B's Avatar
 

Last Online: Aug 10th, 2023 20:15
Join Date: Jun 2010
Location: Ipswich
Default

Yes you may well be correct about the WOT on later turbos, earlier 2.4lh had fuel enrichment, the map for it exists in the bins I've looked through.
It was noted by a guy in the USA who had a 240 that changing the setting between grounded and not while the engine was running caused him issues such as hesitant acceleration etc.
I can only assume it's as you say software, all Volvo EZKs for whatever reason have the map duplicated four times within the bin usually pulling from the third in the bin.
It's possible grounding it while running causes something to go iffy.
As you say running super unleaded means you can just leave it grounded at all times anyway.
I wasn't sure if you intended to have the option between both standard and advanced with a switchable toggle when turning LPG on.
B10B is offline   Reply With Quote
The Following User Says Thank You to B10B For This Useful Post:
Old Oct 28th, 2020, 20:35   #27
Laird Scooby
Premier Member
 
Laird Scooby's Avatar
 

Last Online: Today 13:32
Join Date: May 2012
Location: Lakenheath
Default

Quote:
Originally Posted by B10B View Post
Yes you may well be correct about the WOT on later turbos, earlier 2.4lh had fuel enrichment, the map for it exists in the bins I've looked through.
It was noted by a guy in the USA who had a 240 that changing the setting between grounded and not while the engine was running caused him issues such as hesitant acceleration etc.
I can only assume it's as you say software, all Volvo EZKs for whatever reason have the map duplicated four times within the bin usually pulling from the third in the bin.
It's possible grounding it while running causes something to go iffy.
As you say running super unleaded means you can just leave it grounded at all times anyway.
I wasn't sure if you intended to have the option between both standard and advanced with a switchable toggle when turning LPG on.
The original idea was to have a relay that was energised in parallel with the LPG tank and reducer solenoids so it altered the timing as the LPG came in. However if it really does confuse the system it would be better to have it from start up.

That said i wonder if the guy you mention in the USA had a seriously modified system or something else that was out of the normal set up so when he altered it dynamically it sent things into confusion?

Alternatively, there are 4 different timing settings available, 4 maps apparently duplicated but maybe each is very slightly different somewhere?

If it runs on the third normally that kind of ties in if you assume the 1st is -6 deg, the second is -3 deg, third is standard and the fourth is +3 deg - would also go some way to explaining why it freaked out when dynamically changed.

Just an idea!
__________________
Cheers
Dave

Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........
Laird Scooby is offline   Reply With Quote
The Following User Says Thank You to Laird Scooby For This Useful Post:
Old Oct 28th, 2020, 20:58   #28
B10B
Bald
 
B10B's Avatar
 

Last Online: Aug 10th, 2023 20:15
Join Date: Jun 2010
Location: Ipswich
Default

Yes such issues may have other things involved plus it's just what one person has reported.
As far as I have seen looking though various bins all of the raw data within each of the duplicates remains exactly identical, so although the theory would seem sound that each one might be different for said settings it's not.
There would be no reason not to try your initial setup just because of some guy in the states and my rambling, however should you have an issue it will save chasing a red herring.
B10B is offline   Reply With Quote
The Following User Says Thank You to B10B For This Useful Post:
Old Oct 28th, 2020, 21:15   #29
Laird Scooby
Premier Member
 
Laird Scooby's Avatar
 

Last Online: Today 13:32
Join Date: May 2012
Location: Lakenheath
Default

Quote:
Originally Posted by B10B View Post
Yes such issues may have other things involved plus it's just what one person has reported.
As far as I have seen looking though various bins all of the raw data within each of the duplicates remains exactly identical, so although the theory would seem sound that each one might be different for said settings it's not.
There would be no reason not to try your initial setup just because of some guy in the states and my rambling, however should you have an issue it will save chasing a red herring.
I wonder if the different selections also change a value somewhere else that the main map looks at to find the right values?

It could just be that the system finds the first program that boots without a problem and defaults to number 3 as the start.

I think i might find a switch and try that as a first attempt to see if it throws a wobbler then decide from there whether to hard-wire a switch that can only be changed with the engine off or to put in a relay for dynamic change.
__________________
Cheers
Dave

Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........
Laird Scooby is offline   Reply With Quote
The Following User Says Thank You to Laird Scooby For This Useful Post:
Old Nov 27th, 2020, 23:24   #30
Lolvo 940
Member
 

Last Online: Oct 8th, 2022 20:34
Join Date: Sep 2016
Location: Basingstoke
Default Resolved

Made a new downpipe and had it tig welded properly.
Found my on had fallen apart .
Now my afrs are spot on at idle .!
Couldn't see how bad my downpipe was blowing until I unbolted it and it literally fell in two halves .
Gearbox was stopping it coming apart haha.
Thanks all!
Lolvo 940 is offline   Reply With Quote
The Following 2 Users Say Thank You to Lolvo 940 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 15:00.


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