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Posted by Knudsen1971 on 12-01-2010 04:00 PM:

quote:
Originally posted by hallza
Another thing to check apart from the cold start injector would be the fuel pump relay.

When you turn to position 2 before you crank, you should hear a buzz from the pump which primes the fuel system and squrts some fuel into each cylinder. If you dont hear a buzz, the fuel pump relay 1st stage is at fault and a new relay would be required........

With the first stage of the relay at fault, the pump will run ok but when cranking, it will take a bit longer due to that initial fuel supply not at the engine......

Regards,
Rob.



This is not true for MFI MkII Granada, only on MkIII Granada Scorpio EFI.

As said before, chck valve clearance, ignition timining, sparks, plugs, fuel filter, air leak in the MFI system.
After that, we can continue...


Posted by hallza on 12-01-2010 05:40 PM:

quote:
Originally posted by Knudsen1971
This is not true for MFI MkII Granada, only on MkIII Granada Scorpio EFI.


Knudsen1971, before you start saying what I have described is not true, please look up the fact's first

All MFI injection systems use a relay only system to control the inital squirt of petrol before the pump kicks in to enable the engine to run. On EFI injection systems, the ECU contols the inital squirt of petrol, then the ECU allows the fuel pump relay to energise, therefore allowing the pump to run while the engine is running!

On most MFI systems, there at that age where many people don't realise about the inital squire of petol before cranking, the fault, well the yellow tantalon inside the relay becomes open circuit, making the first stage of the relat inopp, but the main feed via the relay still works.........

Ask any genuine Bosch service centre to clarify my above post.


Posted by mk2 cossie on 12-01-2010 08:06 PM:

also, the standard ford timing settings will be for leaded fuel. unleaded fuel has a lower octane rating and will cause pinking if used. either retard the timing a couple of degrees, or use posh superunleaded


Posted by Knudsen1971 on 13-01-2010 08:03 AM:

quote:
Originally posted by hallza
Knudsen1971, before you start saying what I have described is not true, please look up the fact's first

On most MFI systems, there at that age where many people don't realise about the inital squire of petol before cranking, the fault, well the yellow tantalon inside the relay becomes open circuit, making the first stage of the relat inopp, but the main feed via the relay still works.........

Ask any genuine Bosch service centre to clarify my above post.



Well, thak you for your explanation, I will search for this info. My experience comes form Ford workshop manual Granada and Capri, where this pre-initial squirt is not mentioned. The purple relay should feed the pump only when the dizzy rotates, (so called safety precaution), so it sounded logical to me, that all MFI cars I had (about 10 Granadas)operates the fuel pump only when the starter is operable or engine runs....

I want to ask you, If you are sure, that this relay was mounted to MkII Granada, as I have in my depo also this purple relay form some RS Escort, that looks exactly same as the one from granada, but the inside circuit looks a bit different... that may be the improvemetnt you menioned, but occurs in later MFI Fords....


Posted by Knudsen1971 on 13-01-2010 09:21 AM:

To prove my words, here is the principle of operation form Bosch describing the K-Jetronic principle of operation:
The Fuel Pump Relay
This type of relay is known as a tachometric relay, which means that it only responds and sends a voltage to the pump when the engine is cranking or running. The relay receives a signal from the negative terminal of the coil - this confirms that the engine is turning.
This type of relay is used as a safety device: if the vehicle is involved in an accident when there is a possibility of a fuel line being fractured, the engine will stop due to a lack of fuel, the signal from the coil stops and the supply voltage to the pump is removed.
Typical fuel pump relay connections are as follows:
Terminal Number Connection
30 Permanent battery live
31 Earth
1 or 31b Coil negative
15 Switched 'Ignition on ' voltage
87 Output to fuel pump
NOTE :- while the connections are correct for certain vehicles, the appropriate pins must be identified before testing. Certain relays also perform a pressurisation purge by allowing the pump to run for a second before shutting off, to prime the system.
The location of the relay will vary between motor manufacturers and is in no set position.
When fault finding or fuel pressure testing it will be necessary to have the pump running when the engine is stationary, this can be achieved by bridging terminals 30 and 87 with a small length of wire. For safety reasons it is good practice to insert a ten amp fuse into the bridging wire.
If the engine runs for a while but then stops, failing to restart for a few minutes, feel the relay to see if it is getting warm as this could be the faulty area. Bridging with the fused link wire will confirm the problem.
CAUTION :- do not be tempted to by-pass the relay by bridging between terminal 15 (switched live) and 87 (fuel pump) as this will start the car, but is potentially dangerous.

Here is the schema form Capri 2,8 Ford workshop manual 01/1981:


Posted by Knudsen1971 on 13-01-2010 09:23 AM:

I think personaly you mixed up the principle of operation on K-Jetronic and KE-Jetronic systems, so you can proof Im wrong now, If you can...


Posted by hallza on 13-01-2010 09:36 AM:

Early MFI systems had a saftey switch fitted to the metering unit, but on the later version MFI, (Facelift MK2's) the saftey switch was removed and added to the internal workings of the purple relay. The diagram you've posted is for the pre facelift MK2 NOT the facelift MK2 and MFI fuel systems for 1981 and before......

The MK2 in question at the start of this thread would have the above built into the relay and the saftey switch removed from the metering unit!

I've had an injection MK2 and can confirm the above, i also have a 1984 MK3 capri and too can confirm the above is built into the purple relay.


Posted by Scorpio90 on 13-01-2010 09:39 AM:

Post

hallza is quite right in his post about the violet relay on the MFI system...on first turn of the ignition key..the violet relay primes the fuel system for first starting...yes the violet relay also is a safety device in that for the engine to run the relay gets a voltage from the coil...if the engine should stall or the car be involved in an accident..and the engine stops running..the fuel pump will also stop running...as we dont want fuel all over the place...if the violet relay is faulty....the engine wont run..while knudsen1971 is right in his post about the relays function...hallza is right in his post regarding engine starting procedure and the violet relay. .


Posted by Scorpio90 on 13-01-2010 09:47 AM:

Post

and again hallza is right in his post...the pre-facelift MFI has a safety switch built into the metering unit...and knudsons diagram is showing a pre-facelift system...so to me..hallza did not mix up the operating systems of the MFI and EFI. .


Posted by Knudsen1971 on 13-01-2010 10:26 AM:

quote:
Originally posted by hallza
Early MFI systems had a saftey switch fitted to the metering unit, but on the later version MFI, (Facelift MK2's) the saftey switch was removed and added to the internal workings of the purple relay. The diagram you've posted is for the pre facelift MK2 NOT the facelift MK2 and MFI fuel systems for 1981 and before......

The MK2 in question at the start of this thread would have the above built into the relay and the saftey switch removed from the metering unit!

I've had an injection MK2 and can confirm the above, i also have a 1984 MK3 capri and too can confirm the above is built into the purple relay.


Boys boys.
Yes, you are right, the pics shows prefacelift setup. But the only change to facelift model was, that the safety circuit was switched to the dizzy (colil impulse to relay), nothing else no change to the relay itself I think.
I will go trough the schema I have at home, I have all extensions of Workshop manual till the end of Granada MkII production.
I'm saying, you mixed up K-Jetro and KE-Jetro, not EFI
And again, prove it, show me some schema or Bosch declaration, the same I did. Bosch is not saying anything else than me. And its speaking about the K-Jetronic in general, not only about Ford cars... maybye somebody added the later type of relay to your Capri, but I dont believe it was a factory solution.


Posted by Scorpio90 on 13-01-2010 10:34 AM:

knudsen...have a read of a book written by Mr Ben Watson..its called 'how to tune and modify bosch fuel injection systems'...it covers everything that bosch made..i have a copy..its good reading...tells you how it all works..from MFI..to KE to EFI.... .


Posted by hallza on 13-01-2010 10:38 AM:

The "How to tune and modify bosch fuel injection systems" is an excellent read and will prove what myself and Scorpio90 has said.

The capri i own hasn't been modified at all, its 100% factory standard!

I think it's time you had a closer look at the early and later MFI systems..........


Posted by Knudsen1971 on 13-01-2010 10:52 AM:

Ok, I will have try to find that book.
Or you can send me some copied part, where is explained, from where the purple relay takes power (impulse) when in the second position and "squirting"? That would be helpfull for me...
And as I said, I will go through the schema of Granada. Thanx!


Posted by Knudsen1971 on 13-01-2010 11:11 AM:

quote:
Originally posted by Scorpio90
ok kev.just though knudsen needed a little help in the understanding of the system.. .regards mate...den.


Ok, so please help me (us) and prove your words, only thing you say is find the book. I apollogise for a bit off-topic, but I would like know where the truth is too...


Posted by davew on 13-01-2010 11:42 AM:

Hmmmmm.. is this a private argument or can anyone join in ??

Looks to me like a 'misunderstanding' ... as stated (and repeated) above the purple (fuel pump) relay primes (pressurises) the fuel line feed to the injectors, and then the *ECU* instructs them to 'squirt'...... (and presumably does this in 'position 2' of the ignition switch ?)

I suspect that the problem arose because the Ford 'Principle Of Operation' diagram above is just a (basic) *schematic*, not the *full* circuit diagram, either..... (?)... and so is open to misinterpretation, too (Yes, let's blame Ford !!)

__________________
Owner of Mk2 2.8 GL Estate, Champagne Gold Metallic, Ghia Alloys
X Reg, 74,000 miles from new.


Posted by Knudsen1971 on 13-01-2010 01:00 PM:

Anybody can join this "duel" , of course.:-) It was sepeareted form a MkII Granada tech. thread.

My question is, when and how is the relay forced to "squirt", hence there is any ECU in K-Jetronic system and also Bosch says, that the engine must turn to operate the pump. And the relay itself is earthened just by the neg. form coil... Thats all, when this will be cleared, I can accept this "sqirting" thesis.
The full schema for K-Jetronicis here.


Posted by davew on 13-01-2010 01:49 PM:

Well, I would hope that it is not a 'duel' anyway, just a nice friendly (informed) 'debate' (which somehow it seems escaped from a Mk II Tech Thread)... !!

Anyway, I am not a MKII expert [like Hallza/Scorpio90] but let me try and add some more comments to the *debate* (anyway).....

In the 'normal' operation of starting a car with EFI (and an ECU) then the ECU would be monitoring a number of things, such as 'is the ignition on?' and 'is the engine actually running yet?' etc of course, and it is conceivable that if the answers to these are YES + NO then it (- the ECU -) would 'squirt' some fuel in the cylinders to 'prime' them prior to the engine turning/starting....

As for the diagram above, again it is difficult to see how it works without having the *full* circuit diagram, including the injectors. As I mentioned, Ford (and Haynes too !) do not always give the *full* diagram when they produce such 'schematics', and which can be misleading.

[However I can not see why the *coil* earth is used for the fuel pump relay, as this will be pulsed in time with the 'points/timing' circuit....
or would initially be a 'hard' earth anyway whilst the ignition was in position II.....?]

__________________
Owner of Mk2 2.8 GL Estate, Champagne Gold Metallic, Ghia Alloys
X Reg, 74,000 miles from new.


Posted by Knudsen1971 on 14-01-2010 07:45 AM:

It is friendly debate, however both sides are strong in their oinions :-) As I said it was movede here by Admin form MkII fora, but I dont know why...

This if a full schema, MFI is Mechanical Fuel Injection, there is no ECU, injector is opedned by the pressure of the fuel, all wires and relays etc. included in the system you can see in the schema... and as mentioned before, I have Ford Workshop manuals with all updates of the circuit till 1985.
I was wrong in my previous post, there is "hard" negative earth on term 31, but still Im curious about the "squirt" function of the purple relay. I asked few Granada guys around here and nobody ever heard of such a function on MFI Granada/Capri.
There was a mechanical capacitator on MFi, that kept the main system pressurized, while the car was not in operation, so the meaning od such a function is not necessary, even I would like to be wrong, as such feature is improvemet of the startup of the car...


Posted by davew on 14-01-2010 08:11 AM:

Ok, now we are getting somewhere..... you mean a basic, mechanical, fuel injection system.... So Bosch K, not KE...

Then, according to this information [www.diagnostic-assistance.co.uk/mech_inj.htm ] the initial 'squirting' is not implemented
by a relay in fact but by the thermo-timer + cold start injector, yes ??


So, this is the standard arrangement unless Ford did it differently (as they sometimes do) :-

__________________
Owner of Mk2 2.8 GL Estate, Champagne Gold Metallic, Ghia Alloys
X Reg, 74,000 miles from new.


Posted by Knudsen1971 on 14-01-2010 08:41 AM:

Yes, I mean K, not KE..., the cold-start injector is switched by thermo-time switch, all this system is operated via green relay.
But it just opens the electromagnetic injector to allow the additional mixtuere to come to the intake to improve cold starts.
And of course, the fuel can flow only when the pump is on and the pump is on when the engine is turning (cranking).

What Hallza na Scorpio90 are saying is, that the MFI system has the same ability of activating the fuel pump for short time to pressurize the system when the car is not started yet to improve starting the engine same as on EFI, when the key is in the II.position...

Me, my friends, Bosch manual, Ford workshop manuals and my 10 years of experience says this is nonsense.... but I'm open to new things and as far I know that sometimes can white be black and boys has different opinion and I can accep it. I just asked to prove their thoughts by posting a passage form book they use as source called "How to tune and modify bosch fuel injection systems".

I can understand, that the funciton they mention is "tuning" or improvement, but I'm still 99% sure, that this was not generaly avalaible on Ford MFI Boch K-Jetronic Granadas or Capris.


Posted by davew on 14-01-2010 08:55 AM:

A-ha - the thread moved back again !!

Yes, I meant 'squirting' was 'not done by a *purple* relay' !!.... Obviously there are electronic components involved (although not an ECU with the basic 'K' System).

As I said before, I am not so familiar with the Mk.II arrangements, and exactly how Ford implemented (and maybe modified) the 'K/KE/etc' methods into the MFI... (Hallza/Scorpio90 ?) but I do know that several maunfacturers did not use the 'pure' K system for a number of reasons (mainly emissions ?).

Looks like you have good 'debates/arguments' over in the Mk.II Tech Threads so I will visit again !! The best thing about a *good* debate/argument is that we all learn something, too !

__________________
Owner of Mk2 2.8 GL Estate, Champagne Gold Metallic, Ghia Alloys
X Reg, 74,000 miles from new.


Posted by Knudsen1971 on 14-01-2010 08:59 AM:

Yes, I hope I will learn something new too, but till now I'm just hoping


Posted by LIMEY on 14-01-2010 01:50 PM:

Ok ok......
I have in my possession ( borrowed from hallza) the original ford workshop manuals that cover everything .
I have had a good look over and also double checking the schematic the diagrams and I can assure you both..................I haven't got a clue what any of it means
Maybe the wotsit is playing up or perhaps its the thingymajig at fault.....who knows.

__________________

Old cars have character????
So then I guess character means.......leaks fluids ,terrible handling,rusty ,lousy mpg useless lights and bolts that sheer off


Posted by mk2 cossie on 14-01-2010 02:15 PM:

im gonna guess its the thingymajig personally

ive got a 1600 page ford manual for the mk2 with loadsa wiring diagrams in it. if i get a chance, (or remember to) i'll have a nose at that and see what it says

ive got a mk2 with EEC IV, not any kind of Bosch, so not much help with that part


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