Fordmods Logo

Fuel cut and lean cruise 

 

Page 2 of 3 [ 39 posts ] Go to page Previous  1, 2, 3  Next

 
 Post subject: Re: Fuel cut and lean cruise
Posted: Fri Apr 18, 2014 8:58 pm 
Stock as a Rock
Offline
User avatar

Age: 47

Posts: 178

Joined: 23rd Aug 2012

Gallery: 2 images

Ride: EF Fairmont

Location: Port Macquarie
NSW, Australia

SWC wrote:
Ford quote 470mm of Hg at idle in neutral. This equals 18.5in of Hg. This converts to 9 psi of Vacuum. Are you sure you are measuring inches of mercury or psi.

If you are pulling 11in of Hg at idle, then that is only 5.5psi of vacuum.

If this is the case then this will explain your fuel issue and lack of closed loop. If this is so then you have a vacuum leak and not necessarily on the intake, it could be through your exhaust valves.

Is the cam and head stock?


Yeah, even with a long duration cam I still get around 15-16inHg at idle.
If you have less than that you definitely have either a bad vacuum leak or valve/cam timing problem.

 

_________________

Ported ED XR6 head shaved too much, AU gasket, custom Crow Cam, Pacemaker 4480's, 5-speed conversion, billet aluminium flywheel, GT clutch, T.I. Performance J3 chip, custom water/methanol injection, modified BA throttle body. Paint&Panel by Barbed Wire Fence.

Top
 Profile  
 
 
 Post subject: Re: Fuel cut and lean cruise
Posted: Fri Apr 18, 2014 9:08 pm 
Getting Side Ways
Offline

Age: 41

Posts: 1110

Joined: 27th Dec 2011

Gallery: 6 images

Ride: ef falcon futura

Power: 154 rwkw

Location: Koo Wee Rup
VIC, Australia

SWC wrote:
Ford quote 470mm of Hg at idle in neutral. This equals 18.5in of Hg. This converts to 9 psi of Vacuum. Are you sure you are measuring inches of mercury or psi.

If you are pulling 11in of Hg at idle, then that is only 5.5psi of vacuum.

If this is the case then this will explain your fuel issue and lack of closed loop. If this is so then you have a vacuum leak and not necessarily on the intake, it could be through your exhaust valves.

Is the cam and head stock?

unless he is measuring in in/hgA, then 11in/hga is equal to about 19in/hg

 

_________________

ef futura, pacemakers, 2.5inch catback, k&n panel filter and 3.45 lsd. extractors/cat, ticky head, custom cam grind, t5. now onto cosmetics.

Top
 Profile  
 
 
 Post subject: Re: Fuel cut and lean cruise
Posted: Fri Apr 18, 2014 9:12 pm 
Smokin em up
Offline
User avatar

Age: 34

Posts: 236

Joined: 4th Jan 2009

Ride: ED XR6, AUII XR8

Location: Melbourne
VIC, Australia

I'm measuring MAP, not vacuum, I think that's where the confusion is. I get 11 MAP at idle which is equal to 18 vacuum since atmospheric is 29 today.

 

_________________

ED XR6, LeMans Red, 5-Speed
AUII XR8, Silhouette, 5-Speed

Top
 Profile  
 
 
 Post subject: Re: Fuel cut and lean cruise
Posted: Fri Apr 18, 2014 9:26 pm 
Technical Contributor
Offline

Age: 67

Posts: 6815

Joined: 22nd Jun 2005

Gallery: 8 images

Ride: EF Fairmont

Location: Campbelltown
NSW, Australia

shyun wrote:
I'm measuring MAP, not vacuum, I think that's where the confusion is. I get 11 MAP at idle which is equal to 18 vacuum since atmospheric is 29 today.


If that is the case, then yes you are around 18inhg

barometric pressure - (minus) MAP = intake manifold vacuum.

Can I ask how you are measuring MAP.
Top
 Profile  
 
 
 Post subject: Re: Fuel cut and lean cruise
Posted: Fri Apr 18, 2014 9:31 pm 
Smokin em up
Offline
User avatar

Age: 34

Posts: 236

Joined: 4th Jan 2009

Ride: ED XR6, AUII XR8

Location: Melbourne
VIC, Australia

SWC wrote:
shyun wrote:
I'm measuring MAP, not vacuum, I think that's where the confusion is. I get 11 MAP at idle which is equal to 18 vacuum since atmospheric is 29 today.


If that is the case, then yes you are around 18inhg

barometric pressure - (minus) MAP = intake manifold vacuum.

Can I ask how you are measuring MAP.


Got a crappy GM 1-bar map sensor hooked upto a datalogger and the laptop.

 

_________________

ED XR6, LeMans Red, 5-Speed
AUII XR8, Silhouette, 5-Speed

Top
 Profile  
 
 
 Post subject: Re: Fuel cut and lean cruise
Posted: Fri Apr 18, 2014 9:39 pm 
Technical Contributor
Offline

Age: 67

Posts: 6815

Joined: 22nd Jun 2005

Gallery: 8 images

Ride: EF Fairmont

Location: Campbelltown
NSW, Australia

shyun wrote:
SWC wrote:
shyun wrote:
I'm measuring MAP, not vacuum, I think that's where the confusion is. I get 11 MAP at idle which is equal to 18 vacuum since atmospheric is 29 today.


If that is the case, then yes you are around 18inhg

barometric pressure - (minus) MAP = intake manifold vacuum.

Can I ask how you are measuring MAP.


Got a crappy GM 1-bar map sensor hooked upto a datalogger and the laptop.


Fair enough :D .

So with your Vacuum basicly spot on, that throws the vacuum issue out.

Have you checked your O2 sensor in relation to your fuel issues?

Last edited by SWC on Fri Apr 18, 2014 10:16 pm, edited 1 time in total.

Top
 Profile  
 
 
 Post subject: Re: Fuel cut and lean cruise
Posted: Fri Apr 18, 2014 10:05 pm 
Getting Side Ways
Offline

Age: 29

Posts: 3344

Joined: 19th Dec 2008

Gallery: 1 images

Ride: el fairmont ghia

Location: Farleigh
QLD, Australia

SWC wrote:
Ford quote 470mm of Hg at idle in neutral. This equals 18.5in of Hg. This converts to 9 psi of Vacuum. Are you sure you are measuring inches of mercury or psi.

If you are pulling 11in of Hg at idle, then that is only 5.5psi of vacuum.

If this is the case then this will explain your fuel issue and lack of closed loop. If this is so then you have a vacuum leak and not necessarily on the intake, it could be through your exhaust valves.

Is the cam and head stock?


my DOHC read around the minus 20 area in PSI when at idle

 

_________________

Muts EL Fairmont Ghia
Image
did someone call 9 1 HOLY s**t?

Top
 Profile  
 
 
 Post subject: Re: Fuel cut and lean cruise
Posted: Fri Apr 18, 2014 10:12 pm 
Technical Contributor
Offline

Age: 67

Posts: 6815

Joined: 22nd Jun 2005

Gallery: 8 images

Ride: EF Fairmont

Location: Campbelltown
NSW, Australia

mitchell g wrote:
SWC wrote:
Ford quote 470mm of Hg at idle in neutral. This equals 18.5in of Hg. This converts to 9 psi of Vacuum. Are you sure you are measuring inches of mercury or psi.

If you are pulling 11in of Hg at idle, then that is only 5.5psi of vacuum.

If this is the case then this will explain your fuel issue and lack of closed loop. If this is so then you have a vacuum leak and not necessarily on the intake, it could be through your exhaust valves.

Is the cam and head stock?


my DOHC read around the minus 20 area in PSI when at idle


That is 40in of hg.

Is your gauge reading PSI or Inches Hg?

If it is reading PSI, then your gauge is stuffed Mitch.
Top
 Profile  
 
 
 Post subject: Re: Fuel cut and lean cruise
Posted: Fri Apr 18, 2014 10:35 pm 
Getting Side Ways
Offline

Age: 29

Posts: 3344

Joined: 19th Dec 2008

Gallery: 1 images

Ride: el fairmont ghia

Location: Farleigh
QLD, Australia

psi but was a boost guage, so might read diffrently?

 

_________________

Muts EL Fairmont Ghia
Image
did someone call 9 1 HOLY s**t?

Top
 Profile  
 
 
 Post subject: Re: Fuel cut and lean cruise
Posted: Fri Apr 18, 2014 10:39 pm 
Technical Contributor
Offline

Age: 67

Posts: 6815

Joined: 22nd Jun 2005

Gallery: 8 images

Ride: EF Fairmont

Location: Campbelltown
NSW, Australia

No, Boost gauge works just like a Vacuum Gauge.

Mechanical or electronic gauge?
Top
 Profile  
 
 
 Post subject: Re: Fuel cut and lean cruise
Posted: Fri Apr 18, 2014 10:40 pm 
Stock as a Rock
Offline
User avatar

Age: 47

Posts: 178

Joined: 23rd Aug 2012

Gallery: 2 images

Ride: EF Fairmont

Location: Port Macquarie
NSW, Australia

Do you know what your dashpot gain is set to?
I got much better engine braking and much faster return to idle by changing dashpot gain and modifying dashpot decay rate. I've managed to get it to the point where it performs similar to having isc unplugged above 1200rpm.
I don't think I've ever seen less than 4l/100km in my EF on decel.
I'm pretty sure my fuel cut is working though because there is a noticeable difference in engine braking if neutral switch is connected to ecu or not.

 

_________________

Ported ED XR6 head shaved too much, AU gasket, custom Crow Cam, Pacemaker 4480's, 5-speed conversion, billet aluminium flywheel, GT clutch, T.I. Performance J3 chip, custom water/methanol injection, modified BA throttle body. Paint&Panel by Barbed Wire Fence.

Top
 Profile  
 
 
 Post subject: Re: Fuel cut and lean cruise
Posted: Fri Apr 18, 2014 10:51 pm 
Smokin em up
Offline
User avatar

Age: 34

Posts: 236

Joined: 4th Jan 2009

Ride: ED XR6, AUII XR8

Location: Melbourne
VIC, Australia

SWC wrote:

Fair enough :D .

So with your Vacuum basicly spot on, that throughs the vacuum issue out.

Have you checked your O2 sensor in relation to your fuel issues?


Yeah got a wideband with the datalogger (not currently connected)... I've ran both the narrowband sim off that, and now run a separate bung with the narrowband. No problems there always circles around 14.7.

Did a bit of a search and saw a quote on fiends thread that the neutral switch on the gearbox will disable lean cruise and decal fuel cut...so going to try look into that. It seems to work fine like I said before 5V in gear, 0V in neutral. Although the same quote about it says it should be the opposite?

the-garage-f53/futurlane-ultimate-budget-stories-t69180.html?hilit=lean&start=1680




roughredXR6 wrote:
Do you know what your dashpot gain is set to?
I got much better engine braking and much faster return to idle by changing dashpot gain and modifying dashpot decay rate. I've managed to get it to the point where it performs similar to having isc unplugged above 1200rpm.
I don't think I've ever seen less than 4l/100km in my EF on decel.
I'm pretty sure my fuel cut is working though because there is a noticeable difference in engine braking if neutral switch is connected to ecu or not.


I tried unplugging it but drove the same? I noticed unplugged it reads 5v on the neutral wire to the ECU (pin 30), which doesn't really make sense since there's no circuit unplugged according to the wiring I've seen. Do you know what voltage you get on pin30?

 

_________________

ED XR6, LeMans Red, 5-Speed
AUII XR8, Silhouette, 5-Speed

Last edited by shyun on Fri Apr 18, 2014 10:54 pm, edited 1 time in total.

Top
 Profile  
 
 
 Post subject: Re: Fuel cut and lean cruise
Posted: Fri Apr 18, 2014 10:53 pm 
Getting Side Ways
Offline

Age: 41

Posts: 1110

Joined: 27th Dec 2011

Gallery: 6 images

Ride: ef falcon futura

Power: 154 rwkw

Location: Koo Wee Rup
VIC, Australia

roughredXR6 wrote:
Do you have the neutral switch wired to the ecu? If so check that it's working. If the ecu thinks it's in neutral fuel cut won't work.

neutral switch was mentioned in this thread on the first page

 

_________________

ef futura, pacemakers, 2.5inch catback, k&n panel filter and 3.45 lsd. extractors/cat, ticky head, custom cam grind, t5. now onto cosmetics.

Top
 Profile  
 
 
 Post subject: Re: Fuel cut and lean cruise
Posted: Sat Apr 19, 2014 12:34 am 
Getting Side Ways
Offline

Age: 29

Posts: 3344

Joined: 19th Dec 2008

Gallery: 1 images

Ride: el fairmont ghia

Location: Farleigh
QLD, Australia

SWC wrote:
No, Boost gauge works just like a Vacuum Gauge.

Mechanical or electronic gauge?

electric

 

_________________

Muts EL Fairmont Ghia
Image
did someone call 9 1 HOLY s**t?

Top
 Profile  
 
 
 Post subject: Re: Fuel cut and lean cruise
Posted: Sat Apr 19, 2014 6:41 am 
Technical Contributor
Offline

Age: 67

Posts: 6815

Joined: 22nd Jun 2005

Gallery: 8 images

Ride: EF Fairmont

Location: Campbelltown
NSW, Australia

mitchell g wrote:
SWC wrote:
No, Boost gauge works just like a Vacuum Gauge.

Mechanical or electronic gauge?

electric

Senders f**k.
Top
 Profile  
 
Display posts from previous:
Sort by  
 Page 2 of 3  [ 39 posts ]  Go to page Previous  1, 2, 3  Next

Who is online

Users browsing this forum: No registered users and 35 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

 

 

It is currently Sun Nov 24, 2024 12:22 am All times are UTC + 11 hours

 

 

(c)2014 Total Web Solutions Australia - Australian Web Hosting and Domain Names