Technical Fuel Cut Defender for turbo cinq

[fordcosworth]

right,,,,,,,for those of you that dont no ive had an ongoing problem with the turbo that has been apparent since day 1, some days its fairly good and others its terrible to drive because the fueling runs weak on light throttle before the boost comes in (feels like ive hit a brick wall) or just very hesitant and jumpy.
after reading the ECU live data with a diagnostics reader i discovered that the ECU was seeing 210 mmgh (6 psi) on tick over!!! and this figure rises as i slowly raize the revs, now the MAP sensor in its self is ok and gives out the correct voltage at all stages of vacume and the rest of the engines sensors etc are ok, for a while i have thought it may be ECU related but ive since spoken with a few other forum members and technical advisers who think this could be down to the FCD fitted by Vanaaken, as this is the only reason i can think of why the ECU is seeing positive pressure at all, i have now decided to try a new FCD but there appears to be a few out there, the one fitted now is very small and sealed up, but there is adjutable ones on the net from the likes of greddy, hks, turbosmart etc.
what i want to now is can any of these be fitted to mine and where can i get an origonal one from?? the thor racing one seems to have gone out of production!?

i have had a good look around the foum to see what i could find on info but didnt have much look, maybe not looking hard enough

any help would be great cheers

jason

 

[J333EVO]

Any of the fuel cut defenders mentioned should be fine to use.

VAD themselves used another manufactures one before they made there own very small sealed unit. Mine failed on my car and I bought a new VAD one as they were inexpensive at about £60.

I have read on here of someone who rather than using a FCD just plugged in another Webber Marreli map sensor i.e 2bar as fitted to Fiat Coupes, Lancia integrale, Ford Cosworths, or 2.5 as fitted to Cosworths of even 3 bar as fitted to integrale EVO's they are all sahre same generic plug.

Having not done this myself I can't assure this will work, but 2bar map sensors from Cosworths crop up on ebay all the time cheap from folk who have upgraded to 3bar, often less than £15 and may be worth a try before shelling out on an expensive FCD.

 

[arc]

no, that won't work. Fit an FCD unless you are going to remap the stock ECU to suit the new MAP sensor.

The MAP sensor converts pressure to a voltage signal. The stock MAP sensor can sense from -1bar to 1bar (ie atmosphere). At -1bar, the MAP sensor is giving a 0v signal. At 1bar it is giving 5v. If you replace that with a sensor capable of measuring boost then you'll screw that up. A 3bar sensor for example, might read 0v at -1bar, 2.5v at 1bar and then 5v at bar. Unless the lookup tables on the ECU are reprogrammed to suit the new sensor, then it'll just get confused. The sensor will be reading 2.5v at 1bar, and the ECU will be expecting 5v at 1bar.

edit; or just build one - its essentially just 3 OP amps, which u can have on one chip quite neatly;

http://www.graphics.cornell.edu/~v/fcd/

 

[Slosei]

A 2bar map sensor will work but the fuel map as already stated will be all over the place so needs bit more time and money stick to the fcd route.
Evidence for it working is my sei mpi turbo but thinking back to costs it would be cheaper to use mega squirt
Zak

 

[Slosei]

Forgot to put im still on a standard map

 

[arc]

Evidence for it working is my sei mpi turbo but thinking back to costs it would be cheaper to use mega squirt
Zak

didn't that one blow up though using that kind of setup?

 

[Slosei]

Yes blown it loads of times lol once i have had the head off and on 5 times in a week trying to get it running after the bottom pully on the crank shaft sheared off its woodruff key imagine rest luckyly i only bent 4 valves iirc,
Piston rings are badly worn due to the bore wash with it running so rich on boost.
it managed to drive to york about 50miles away, spend a day driving it on the drag strip and make it back home still running might be on to a winner.
Its running 1bar of boost now with a t2 turbo which is slightly bigger and flow bit more air than a gt15@same boost pressure? And its running with a standard head gasket. I have been through atleast 4radiators with the turbo hitting radiator which is all sorted now with a punto turbo diesel radiator squeezed in more surface area less depth and i do have an oil cooler but not plumbed it in yet. its made a trip from west yorkshire to norwhich and back in a day in record time lol. Need to cover
when i cover 90k miles without a rebuild then id say the car is reliable

 

[Brooky]

Sounds like your car has been thrown together.

 

[Slosei]

Yes it has been thrown together lol its only a seicento lol i bought a high milage p75 engine and took it from there in trying different stuff like finding an ideal compression ratio for the turbo i am using to keep detonation away evan if using 95ron fuel if not available for whatever reason.for safety
stuff like that takes time would be a lot cheaper to get someone who has the time and experience to build a reliable fast sei but i dont learn anything from that do i.
Compare the power and torque from my power graph to the standard p75 running lean off boost means more power with increased amount of heat car is easy to drive, drivers like a standard 1242 mpi sei oh and i have never had a holy piston! But i have melted rings twice and now bore wash is killing the rings no boost exhaust is restrictive as hell at the back box the 2inch stainless middle section reduces to 1-3/4 inch and it also has a middle box in to keep the noise down so at first glance it looks like a standard sei with a normal looking pipe out the rear no shiny stainless tail pipe a dull 2inch silver tail pipe standard looking only give away is the over sized punto radiator and looking closer can see the punto gt intercooler so front bumper has been chopped up to hell with stuff being changed around and space
cant forget the dent in the tail gate and rear bumper lol do have a silver sei s tail gate same but no spoiler waiting to get fitted as well as the other engine i have in organised bits awaiting some work on head skimming etc block needs deglazing or honing dont know what weight fly wheel to use etc etc i get my licence back in oct so got untill then

 

[Brooky]

dont know what weight fly wheel to use

Light as possible

 

[Slosei]

Thats the thing i have never really tried a light fly wheel yes it will rev quicker but cos of me still using standard management it would keep stalling but will try it eventually. Been thinking hard if i should keep it as it is or stripped out.
Stripping it out costs nothing relativly simple task but like the back seat, like a quiet car standard looking car.
Maybe later when it the main second car,
but like the look of. wolf in a nasty looking sheep outfit lol
id evan say that the power graph is wrong but look at the torque curve lol nice gradual increase, still have bit more torque over the standard punto75 max torque at 4k rpm
with such a low compression.
All i need now is traction control like a race logic or a lsd

 

[Slosei]

Sorry for hijacking it.
Here is one i found from ages ago the dent is not on this shot but tail pipe is visible

 

[fordcosworth]

thanks everyone for the replys,,,,well i think im going to go down the simple root of just replacing the current FCD with a new one from one of the names mensioned above, just really wanted to no that any would work really, ive seen some advertised that say only suitable for skyline gtr, supra etc.s want sure what to do.
they range in price a fair bit, from 60-140 quid!! dont no which one to go for yet.

cheers

 

[gazzaman2k]

i used to use a HKS one on mine that i found on ebay for £40 that worked atreat 4 wire version adjustable too.

Tricker uses just a resistor places between the map sensor pins on his turbo setup to stop the car seeing boost its a mod for less then £1

 

[fordcosworth]

i used to use a HKS one on mine that i found on ebay for £40 that worked atreat 4 wire version adjustable too.

Tricker uses just a resistor places between the map sensor pins on his turbo setup to stop the car seeing boost its a mod for less then £1

brilliant cheers mate
i actually have one of those variable resistors (adjustable with a nob) of ebay,,,,its one of those daft ones that clame to give 20 bhp :yuck:

but dont worry i didnt buy it for that i bought it for testing things like sensor for guages in cars etc at work, i still have it but wouldnt no where to start in terms of fitting it to the map sensor

 

[allanhelen]

The point of the FCD is to clamp the MAP voltage at WOT so basically they will all do that, the MF2 then picks up any additional fueling.

The more expensive ones have other features but they are not really required for this application

As an aside one of the reasons i'm installing the e-manage is that it does this as std

 

[Whiley]

go for the thor racing one, so much better than the others imo if i was gonna break my bits up would have let you have mine but not an option at the mo

 

[randomizered]

A resistor to reduve the voltage on the map sensor is a real bodge, unless you get a total remap.

It may reduce voltage at WOT enough to not trigger the fuel cut, but it will also reduce the output across ALL the sensor output, so you'd need a rempa to compensate.

A circuit that allows the MAP sensor to operate normally, but limits the total voltage output, is what you need, as these FCD's do...don't skim on a relatively simple component.

The thing i don't like about these FCD's, is that you are still on the stock ecu map in boost, using a NA ignition map. Timings are probably a lot higher than an aftermarket or remapped system would run, which can lead to loss of power or pinking.

Unless I a missing something?

Cheers,

Kristian

 

[arc]

*throws this drawing at Kristian*

The thing i don't like about these FCD's, is that you are still on the stock ecu map in boost, using a NA ignition map. Timings are probably a lot higher than an aftermarket or remapped system would run, which can lead to loss of power or pinking.

Unless I a missing something?

thats why the MF2 approach is, well, flawed. iirc some of the vad cars had the stock ECU remapped with a 'better' spark table. but not all (not even many) did.

 

[fingers99]

Yep, Arc has it. Add to that that there's no safety whatsoever and that on SPI set ups no.4 plug can get very hot.............