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With the 14CUX (Hotwire) injection system how is the "speed" sensor information provided in vehicles that have an old style speedo cable rather than a more modern electronic speedo.
Also - in a D1 or RRC with Hotwire injection, where does the ECU take its ignition signal from? The low tension side of the ignition coil?
Thanks
Garry
Yep, picks up from the ignition coil. Apart from that all you need is B+ and switched B+, and an earth - very simple setup to retrofit.
The speed sensor controls injection cut off at more than 1500RPM and throttle less than 0.49 volts and positive speed . IE down hill.Quote:
With the 14CUX (Hotwire) injection system how is the "speed" sensor information provided in vehicles that have an old style speedo cable rather than a more modern electronic speedo.
It also controls idle stepper at low speed (under 1500RPM ) when approaching stop ie throttle below 0.49. It holds revs to approx. 1200 to smooth the change to first in the auto.
It takes the signal from the speedo sensor. If you were really nerdy you could get a driveshaft sensor for a cruise control and set it up to give a pulse I guess, although the math may be interesting although I suspect it is only pulse vs no pulse.
But really the penalty for not having the injector cutoff and idle up is not all that great. My TPS was disconnected for about a year and I didn't notice ( although I did notice no injector cutoff as it was very pronounced with the Thor manifold) , but I had O2 sensors fitted which do all the mixture control at less than 1/2 throttle. I had over crimped a join in the TPS wires which cut a wire and negated the TPS signal.
Regards Philip A
Thanks Philip and Gav,
Philip - on the speed sensor thing - I did read that the 14CUX ECU expects to see about 8000 pulses per mile but as usual cannot finds the reference right now - but I assume all it needs is to see lots of pulses when at speed and no pulses when stopped. I have an old cruise control kit at home that has tailshaft magnets and a pickup - might be suitable - also I believe signal generators that go on the speedo cable are available so some options there.
I dont have a dizzy on my engine and ignition is going to be controlled by EDIS 8 and Megajolt. I need to work out what the equivalent of B+ is on a traditional coil. My system has two coil packs (4 coils in all) but they are fed with a a common 12v positive with the system switching through the relevant coil low tension side to earth (just like B+ on a traditional coil) - so the number pulses going into the coil system is basically the same as a traditional dissy and coil setup.
Another aspect is to take a signal from what is called the SAW signal from the Megajolt unit. Basically, crankshaft sensor signals are received by the EDIS unit and then sent to the Megajolt Control unit (called a PIP signal) where this signal is delayed or advanced (normally advanced to advance ignition timing with increased revs etc) and this SAW signal is sent back to the EDIS system where it then fires the coils (wasted spark). This SAW signal should also work with the 14 CUX ECU but it may not be a 12v signal - dont know yet.
For those who do not know EDIS is a Ford system fitted to many late 90s - early 2000 cars - comes in 4, 6 and 8 cylinder versions - in Aust fitted to 90s Mustangs, 2000s Festivas, Focus and Modeos. The beauty of the Edis system is that it can still work if the car's ECU has failed as it is capable of running in a default mode of a fixed 10 BTDC. I dont have the Megjolt ignition module as yet but have been driving my 101 around on LPG (carbs not working) and EDIS in default mode with no issues - it is amazing that with fixed ignition timing all seems to work as per normal.
Plan is to get the carbs working - full ignition control then swap out the carbs for the 14CUX injection system - and injected LPG. I want each component to be working so that when I make changes I am only testing on new item not the whole lot.
Thanks
garry
I looked at EDIS for my 3.9 but By that stage I already had a Unichip fitted which took over the vacuum advance portion of the dizzy ( which I completely deleted) but left the centrifugal advance in effect electronically controlling advance and creating an electronic advance profile/map . I don't know why they didn't lock the dizzy at the same time but that was how it was done. I think you can buy a crank pulley sensor and Megajolt as a full kit from the UK
I would have fitted EDIS to the crank pulley but you would have a crank sensor position on a 4.6 along with a slotted flywheel/flex plate.
You get most fuel economy from the level of advance at light throttle/lower revs and the RV8 can take lots more advance. Apparently they limited advance at lower revs to reduce NOX emissions. So locked at 10degrees is not ideal as it can take 30 on light throttle.
Regards Philip A
Hi Philip - you seem to be the resident expert on the 14CUX. [smilebigeye]Quote:
Originally Posted by PhilipA
I was speaking to a friend that has a 14CUX in his 101 and he confirmed that he does not have a speed sensor and his system works fine - idles etc with no issues however he was not sure of the specifics.
From you comments above you seem to think it is not all that important.
I am thinking of proceeding without it and see what happens. I am looking at getting one of Homestars GPS speedos for the 101 so will not need a speedo drive and Justinc has advised a TD5(LT230) speedo transducer will fit a LT95 so provide the speed pulses if the ECU actually needs them.
Cheers
Garry