MFI?
Moderators: hot66, impmad2000, Barry, Viv_Surby, Derek, Mike Usiskin
-
- I need to get out more!
- Posts: 3277
- Joined: Mon Apr 26, 2004 7:51 am
- Location: Selby
MFI?
OK have now got my RS Replica. What a car!! Stunning performance compared to my 'late' 3.2.
But........
A few challenges ahead:
1. Need to get fuel consumption into double figures!! - if only to save the planet. Symptoms: When warm, tickover was about 3000rpm. Seem to have cured that by resetting all the operating rods on the MFI but now barely ticks over!
2. Looking through the Haynes manual I think I'm missing some bits. Mainly the regulator housing (the piece that mixes hot/cold air and connects to the air filter housing) and associated hoses - is this REALLY needed? At a guess I'd say that this part has never been fitted on this hybrid. The Haynes manual suggests that if this regulator is not fitted then the engine will always run rich, thinking it's cold outside.
3. Popping/crackling through the exhaust at tickover and on overrun. System fitted is a fairly 'open' stainless steel 2 central pipe set up. Although it's quite an intoxicating noise I guess it's pretty annoying to non-DDK'ers.
All of the above points to the MFI - right?
Having spent all day 'fiddling' I decided to read and research before doing anything else. Glad I did - information gleaned (via Pelican) suggests that there is a set sequence to setting up the MFI (check - think - repair)
Once set up what mpg should I expect (once I've got over the fist flush and remove the lead boots!)??
But........
A few challenges ahead:
1. Need to get fuel consumption into double figures!! - if only to save the planet. Symptoms: When warm, tickover was about 3000rpm. Seem to have cured that by resetting all the operating rods on the MFI but now barely ticks over!
2. Looking through the Haynes manual I think I'm missing some bits. Mainly the regulator housing (the piece that mixes hot/cold air and connects to the air filter housing) and associated hoses - is this REALLY needed? At a guess I'd say that this part has never been fitted on this hybrid. The Haynes manual suggests that if this regulator is not fitted then the engine will always run rich, thinking it's cold outside.
3. Popping/crackling through the exhaust at tickover and on overrun. System fitted is a fairly 'open' stainless steel 2 central pipe set up. Although it's quite an intoxicating noise I guess it's pretty annoying to non-DDK'ers.
All of the above points to the MFI - right?
Having spent all day 'fiddling' I decided to read and research before doing anything else. Glad I did - information gleaned (via Pelican) suggests that there is a set sequence to setting up the MFI (check - think - repair)
Once set up what mpg should I expect (once I've got over the fist flush and remove the lead boots!)??
Merc B Class diesel
Porsche-less
Porsche-less
-
- I need to get out more!
- Posts: 3277
- Joined: Mon Apr 26, 2004 7:51 am
- Location: Selby
MFI
Should have searched this site first, shouldn't I?
Regulator not required, right?
Good job it's Bank Holiday so I can tinker again - check/correct rod lengths, check/clean thermostat.
Must get it running right for Harewood next weekend!
Any other help/insights would be helpful to this MFI novice.
Thanks
Regulator not required, right?
Good job it's Bank Holiday so I can tinker again - check/correct rod lengths, check/clean thermostat.
Must get it running right for Harewood next weekend!
Any other help/insights would be helpful to this MFI novice.
Thanks
Merc B Class diesel
Porsche-less
Porsche-less
On 'steady' motorway runs my car will get about 22 mpg. On country roads when I'm having fun I can get anything down to 8 mpg
Popping on the over run... could be down to the fuel cut off ( I think thats what its called) switch not be activated. Its located on the left hand side
( looking at the rear of the car) and operated by the linkage. This is meant to be activated when the throttles are shut and cuts off the fuel......although my car still POPS & BANGS if I have been driving steady. The engine behaves a LOT better after it has spent a lot of time near the red line
I have a copy of the MFI manual if you wanted to have a look, although my 'practical' experince of messing with MFI is limited
I can bring the MFI manual to Harewood for you to have a look through or if your up in the Bedale area you could pop in
Popping on the over run... could be down to the fuel cut off ( I think thats what its called) switch not be activated. Its located on the left hand side
( looking at the rear of the car) and operated by the linkage. This is meant to be activated when the throttles are shut and cuts off the fuel......although my car still POPS & BANGS if I have been driving steady. The engine behaves a LOT better after it has spent a lot of time near the red line
I have a copy of the MFI manual if you wanted to have a look, although my 'practical' experince of messing with MFI is limited
I can bring the MFI manual to Harewood for you to have a look through or if your up in the Bedale area you could pop in
James
1973 911 2.4S
1993 964 C2
2010 987 Spyder
1973 MGB Roadster
Its not how fast you go, but how you go fast
1973 911 2.4S
1993 964 C2
2010 987 Spyder
1973 MGB Roadster
Its not how fast you go, but how you go fast
-
- Nurse, I think I need some assistance
- Posts: 9424
- Joined: Sat Nov 08, 2003 6:59 pm
- Location: East Sussex
- Contact:
I had a Carrera 2.7 that lost the 1" hose from the left heat exhanger to the MFI thermostat. Make sure that it connected correctly otherwise the MFI always thinks the motor is running cold and will use loads of fuel.
You do not need the intake valve.
Popping and cracking sounds like an air leak somewhere which will also afftect tickover
I used to get around 17 mpg on the road 10-12 on a track day
You do not need the intake valve.
Popping and cracking sounds like an air leak somewhere which will also afftect tickover
I used to get around 17 mpg on the road 10-12 on a track day
-
- DDK forever
- Posts: 631
- Joined: Sat Jan 31, 2004 10:22 am
- Location: The South Hams
- Contact:
-
- I need to get out more!
- Posts: 3277
- Joined: Mon Apr 26, 2004 7:51 am
- Location: Selby
Guys
Thanks for your replies.
Hot66 - Thanks for the offer of a 'look-see" at the MFI manual. Managing with info from Pelican so far, so will let you drive to Harewood not weighed down! Fuel cut off switch is operating (well it 'clicks' when the actuating arm/thing touches it)
Nick - You seem to have identified the problem! Hose from heat exchanger is missing!! I overlooked this yesterday, as there is a piece of hose from the thermostat down to the tin ware and I assumed that it went through to the H/E. Should have looked under the car! The piece from the tin ware to the H/E is missing - will try & source tomorrow. Assuming this helps towards improving the mpg then I'll start looking for a leak/s. Must say that popping/crackling is much reduced once everything is hot. Perhaps a good few runs to 6000+ have helped clear its' throat?
Bob Salmon (et al) thanks for your mpg info. I still have lead boots on (will the novelty wear off?)!
Thanks for your replies.
Hot66 - Thanks for the offer of a 'look-see" at the MFI manual. Managing with info from Pelican so far, so will let you drive to Harewood not weighed down! Fuel cut off switch is operating (well it 'clicks' when the actuating arm/thing touches it)
Nick - You seem to have identified the problem! Hose from heat exchanger is missing!! I overlooked this yesterday, as there is a piece of hose from the thermostat down to the tin ware and I assumed that it went through to the H/E. Should have looked under the car! The piece from the tin ware to the H/E is missing - will try & source tomorrow. Assuming this helps towards improving the mpg then I'll start looking for a leak/s. Must say that popping/crackling is much reduced once everything is hot. Perhaps a good few runs to 6000+ have helped clear its' throat?
Bob Salmon (et al) thanks for your mpg info. I still have lead boots on (will the novelty wear off?)!
Merc B Class diesel
Porsche-less
Porsche-less
You can get the MFI manual "Check, Measure, Adjust" by downloading it but I can't remember where from. If you can't find it PM me and I'll email it to you.
Richness can also be caused by your injectors being worn out. You end up with a car that's difficult to set up. Mine are worn and it runs too rich at idle to keep it running well at high revs. I think injectors are about £80 each!!!
Richness can also be caused by your injectors being worn out. You end up with a car that's difficult to set up. Mine are worn and it runs too rich at idle to keep it running well at high revs. I think injectors are about £80 each!!!
I'm sure you've already looked on here:
http://www.pelicanparts.com/techarticle ... TipMFI.htm
There is the link for the 'check measure adjust' manual
http://www.pelicanparts.com/techarticle ... TipMFI.htm
There is the link for the 'check measure adjust' manual
James
1973 911 2.4S
1993 964 C2
2010 987 Spyder
1973 MGB Roadster
Its not how fast you go, but how you go fast
1973 911 2.4S
1993 964 C2
2010 987 Spyder
1973 MGB Roadster
Its not how fast you go, but how you go fast
-
- I need to get out more!
- Posts: 3277
- Joined: Mon Apr 26, 2004 7:51 am
- Location: Selby
Double-figure mpg!
MFI report:
As suggested by Nick Moss - putting in the piece of hose from the H/E to the tinware DOES make a difference. Gone is the smell of unburnt fuel AND I even managed the trip to Harewood without having to buy more fuel!
At the moment the 'repair' is cobbled up using a piece of aluminised heater ducting, awaiting proper parts from JCT600. Dave 'The Legend' Sutherland at Strasse will be treating the MFI to a proper set-up soon.
As suggested by Nick Moss - putting in the piece of hose from the H/E to the tinware DOES make a difference. Gone is the smell of unburnt fuel AND I even managed the trip to Harewood without having to buy more fuel!
At the moment the 'repair' is cobbled up using a piece of aluminised heater ducting, awaiting proper parts from JCT600. Dave 'The Legend' Sutherland at Strasse will be treating the MFI to a proper set-up soon.
Merc B Class diesel
Porsche-less
Porsche-less
Glad it's sorted, the "check measure adjust" manual is invaluable.
In case you haven't done this already it is worthwhile taking the bi-metalic swich in the thermostat housing apart and cleaning it up with some carb cleaner so your cold start switch works correctly. Be very careful when you take the end cap off as the switch is spring loaded and you DO NOT want to lose any of the discs or get them in the wrong order.
It's also worth ensuring the fuel microswitch that James mentioned is adjusted as per the description in "check measure adjust" to cut down on those backfires (mind you mine still backfires on over-run every now and then)
In case you haven't done this already it is worthwhile taking the bi-metalic swich in the thermostat housing apart and cleaning it up with some carb cleaner so your cold start switch works correctly. Be very careful when you take the end cap off as the switch is spring loaded and you DO NOT want to lose any of the discs or get them in the wrong order.
It's also worth ensuring the fuel microswitch that James mentioned is adjusted as per the description in "check measure adjust" to cut down on those backfires (mind you mine still backfires on over-run every now and then)
Porscheless but still aircooled
-
- I need to get out more!
- Posts: 3277
- Joined: Mon Apr 26, 2004 7:51 am
- Location: Selby
Progress
Have had the car at Strasse for "The Legend" to give it the benefit of his experience. Result.............
Re-timed ('bit out')
Points gap re-set ('almost closed')
Air screws (intakes) balanced
One disc added to thermostat 'thing' (?)
Mixture weaked (7 'clicks' - ?)
Faulty cut-off relay (on order)
Driving result.......
Tickover steady at 900/100 rpm
Smell of unburned fuel gone
Minor popping through exhaust on overrun (should go when relay obtained)
It's now even more of a 'screamer'! Rev limiter works!
All-in-all satisfactory so far. At least it's given me a baseline to work from for future tinkering. Interesting remark from DS - keep checking the oil, the level MIGHT rise, due to unburned fuel passing the piston rings (cut off not working) and diluting the oil. Change oil regularly if this starts to happen. A problem DS had when looking after Jack Todoff's "rally car" (a 'proper' RS if I remember correctly) in the early 70's
Hope this helps any other DDK'ers that might have similar problems
Re-timed ('bit out')
Points gap re-set ('almost closed')
Air screws (intakes) balanced
One disc added to thermostat 'thing' (?)
Mixture weaked (7 'clicks' - ?)
Faulty cut-off relay (on order)
Driving result.......
Tickover steady at 900/100 rpm
Smell of unburned fuel gone
Minor popping through exhaust on overrun (should go when relay obtained)
It's now even more of a 'screamer'! Rev limiter works!
All-in-all satisfactory so far. At least it's given me a baseline to work from for future tinkering. Interesting remark from DS - keep checking the oil, the level MIGHT rise, due to unburned fuel passing the piston rings (cut off not working) and diluting the oil. Change oil regularly if this starts to happen. A problem DS had when looking after Jack Todoff's "rally car" (a 'proper' RS if I remember correctly) in the early 70's
Hope this helps any other DDK'ers that might have similar problems
Merc B Class diesel
Porsche-less
Porsche-less