Help with EEC IV
Discussion
Righ o
EEC IV didn't actually do a lot for making the spark, EDIS (electronic distributorless ignition system) did that, but it used a few of the EEC IV signal wires, most importantly was the crank position sensor and the cable from EEC IV to EDIS which carries the SAW signal (spark advance word)
Does the fuel pump prime when you first key on?
Does the car have an aftermarket immobiliser which might be at fault?
but first off, can we have a little more details, how have you decided it's an ignition fault?
If you have access to a noid light it saves hours of messing about, if so, get it plugged into the crank sensor and see if it flashes as the voltage is induced, worn out thrust washers on the crank can create an excessive air gap killing the signal.
EEC IV didn't actually do a lot for making the spark, EDIS (electronic distributorless ignition system) did that, but it used a few of the EEC IV signal wires, most importantly was the crank position sensor and the cable from EEC IV to EDIS which carries the SAW signal (spark advance word)
Does the fuel pump prime when you first key on?
Does the car have an aftermarket immobiliser which might be at fault?
but first off, can we have a little more details, how have you decided it's an ignition fault?
If you have access to a noid light it saves hours of messing about, if so, get it plugged into the crank sensor and see if it flashes as the voltage is induced, worn out thrust washers on the crank can create an excessive air gap killing the signal.
nighthawk said:
Righ o
EEC IV didn't actually do a lot for making the spark, EDIS (electronic distributorless ignition system) did that, but it used a few of the EEC IV signal wires, most importantly was the crank position sensor and the cable from EEC IV to EDIS which carries the SAW signal (spark advance word)
Does the fuel pump prime when you first key on?
Does the car have an aftermarket immobiliser which might be at fault?
but first off, can we have a little more details, how have you decided it's an ignition fault?
If you have access to a noid light it saves hours of messing about, if so, get it plugged into the crank sensor and see if it flashes as the voltage is induced, worn out thrust washers on the crank can create an excessive air gap killing the signal.
yes we have fuel pump
no there is no immobeliser
Engine has just had a rebuild including pistons/rebore/rings/crank grind new big ends mains and oil pump thrust washers etc
i have power to the coil and also have power down both wires to the crank sender also had the gear box off to measuere the gap between the cps and fly wheel and is 4mm
Whats a noid light were do i get one
>> Edited by jimmyfish on Sunday 7th August 11:23
>> Edited by jimmyfish on Sunday 7th August 16:46
A noid light is a small LED lamp which can be inserted into the multiplugs.
very handy for checking injector harnesses, coil signals and the like.
Lucas used to market one as an injector lead tester, not sure how much though. I bought 3 off snap on about 12 years ago.
I'll see if I can find any diagnostic stuff for EDIS when I go back into work.
Power feeds and earths to edis can be checked with a meter...once I can find something with the pin numbers on
very handy for checking injector harnesses, coil signals and the like.
Lucas used to market one as an injector lead tester, not sure how much though. I bought 3 off snap on about 12 years ago.
I'll see if I can find any diagnostic stuff for EDIS when I go back into work.
Power feeds and earths to edis can be checked with a meter...once I can find something with the pin numbers on
You say that the noid light showed nothing when plugged into either the injector harness connectors or the coil pack?
That would point to loss of signal from the crank position sensor..
on that car, find the EDIS module and check the pins.
pin 1 should be the digitised signal to the EEC IV module's pin 56....thats the profiled ignition pickup (PIP)
Pin 2 is the EDIS diagnostic monitor, pin 4 0r 28 EEC Iv depending on spec
Pin 3 is rather important as it's the Spark Advance word (SAW) from the EEC IV module, without it the timing is frozen at 10 degrees btdc
Pin 4 and 9 are connected internally and then go to earth via pin 9
Pin 5 and 6 are the crank position sensor signal wires, you can check the CPS signal here with a multi meter, cranking should show around 1.5Vac if the airgap and sensor are Ok. Resistance check down the cables needs to be around 460 ohms Check that AIR GAP if there is no voltage ideally 0.8mm is what your after, if it is at 4MM as you say...thats the problem!!!
pin 7 is the screening around the CPS wiring to sheild noise, shouldn't really be a problem.
Pin 8 is the 12v feed to the module, this comes via the power hold relay.
pin 10 and 12 are the switching signals to the coil pack, these should have been making the noid light flash during cranking.
Pin 11 is the signal for the tachometer on EDIS 4, if it was EDIS 6 it's be used to fire the 3rd coil.
Briefly speaking
Loss of Crank Position Sensor will cause NO SPARK, NO INJECTOR FIRING and NO FUEL PUMP while cranking
Loss of PIP will cause NO FUEL PUMP during cranking BUT you will have SPARK and INJECTORS
Loss of SAW will freeze the timing at 10degrees, will still start and run !!!!
Loss of the Edis Diagnostic Monitor (EDM) will still run.
Some expanded details will be helpful for further help, you need to know that the fuel is being delivered to the fuel rail...messy but needed during cranking, not just for the initial 2seconds when the key is switched to POSII
>> Edited by nighthawk on Tuesday 16th August 20:24
That would point to loss of signal from the crank position sensor..
on that car, find the EDIS module and check the pins.
pin 1 should be the digitised signal to the EEC IV module's pin 56....thats the profiled ignition pickup (PIP)
Pin 2 is the EDIS diagnostic monitor, pin 4 0r 28 EEC Iv depending on spec
Pin 3 is rather important as it's the Spark Advance word (SAW) from the EEC IV module, without it the timing is frozen at 10 degrees btdc
Pin 4 and 9 are connected internally and then go to earth via pin 9
Pin 5 and 6 are the crank position sensor signal wires, you can check the CPS signal here with a multi meter, cranking should show around 1.5Vac if the airgap and sensor are Ok. Resistance check down the cables needs to be around 460 ohms Check that AIR GAP if there is no voltage ideally 0.8mm is what your after, if it is at 4MM as you say...thats the problem!!!
pin 7 is the screening around the CPS wiring to sheild noise, shouldn't really be a problem.
Pin 8 is the 12v feed to the module, this comes via the power hold relay.
pin 10 and 12 are the switching signals to the coil pack, these should have been making the noid light flash during cranking.
Pin 11 is the signal for the tachometer on EDIS 4, if it was EDIS 6 it's be used to fire the 3rd coil.
Briefly speaking
Loss of Crank Position Sensor will cause NO SPARK, NO INJECTOR FIRING and NO FUEL PUMP while cranking
Loss of PIP will cause NO FUEL PUMP during cranking BUT you will have SPARK and INJECTORS
Loss of SAW will freeze the timing at 10degrees, will still start and run !!!!
Loss of the Edis Diagnostic Monitor (EDM) will still run.
Some expanded details will be helpful for further help, you need to know that the fuel is being delivered to the fuel rail...messy but needed during cranking, not just for the initial 2seconds when the key is switched to POSII
>> Edited by nighthawk on Tuesday 16th August 20:24
my car is a 1995 model Escort Cosworth small turbo.
As the car is now 10 years old many wires are brittle and cracking. The car is used for hillclimbs and so the complete wiring loom was removed and checked. I am now fitting a custom loom, however the EDIS and EEC terminals are hard to find. Also some of the connections to the EEC module ar enot 100% clear.
Any help here would be appreciated.
cheers.
As the car is now 10 years old many wires are brittle and cracking. The car is used for hillclimbs and so the complete wiring loom was removed and checked. I am now fitting a custom loom, however the EDIS and EEC terminals are hard to find. Also some of the connections to the EEC module ar enot 100% clear.
Any help here would be appreciated.
cheers.
Kenny
After checking the system for the info you need, i'm afraid we don't have anything that covers the entire system in 1 go, I picked up your email this evening with the attached document, i'll have a bash at filling in the blanks tomorrow for you. The progress so far looks spot on.
After checking the system for the info you need, i'm afraid we don't have anything that covers the entire system in 1 go, I picked up your email this evening with the attached document, i'll have a bash at filling in the blanks tomorrow for you. The progress so far looks spot on.
s2turbodave said:
Hi guys been reading your posts I have got the same trouble on my escort rs turbo we have fitted a 2.1 zvh and converted it over to efi but got no spark which colour wire was the earth on the edis unit was it the black earth wire which was broken on ours?
Check this diagram outhttp://i27.photobucket.com/albums/c163/Safechav/Ra...
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